Medicinski pregled
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ADVERSE EFFECTS OF OXYGEN: Adverse effect of oxygen on anaerobes implies oxidation of the basic cell constituents NAD(P)H, thiols, iron-sulphur proteins, pteridines and others) and inactivation of the essential components of the active site of enzymes. Oxygen can also adversely affect the aerobes, especially if long-term influence is taken into consideration, while exposition to high-pressure oxygen causes considerable damages. Direct influence of oxygen on aerobes due to slow and limited enzyme inactivation (for example glutamate decarboxylase) and small number of affected "targets" is not responsible for total adverse effects of oxygen. ⋯ OXIDATIVE STRESS: Protection of an organism from oxygen free radicals implies activity of enzymatic (catalase, SOD, glutathione peroxidase, glutathione reductase etc.) and nonenzymatic (vitamin E. vitamin C. glutathione, uric acid etc.) systems of protection. Disturbance of the balance between production of oxygen free radicals (or some other radical species) and activity of antioxidative system of protection causes the so called oxidative stress. An organism can tolerate a mild oxidative stress but a higher disturbance between the production of free radicals and the activity of the antioxidative protection results in lipid protein and DNA as well as numerous diseases.
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Wound healing is a complex process involving interactions among a variety of different cell types. The normal wound repair process consists of three phases--inflammation, proliferation, and remodeling that occur in a predictable series of cellular and biochemical events. Wounds are classified according to various criteria: etiology, lasting, morphological characteristics, communications with solid or hollow organs, the degree of contamination. In the last few years many authors use the Color Code Concept, which classifies wounds as red, yellow and black wounds. This paper presents conventional methods of local wound treatment (mechanical cleansing, disinfection with antiseptic solutions, wound debridement--surgical, biological and autolytic; wound closure, topical antibiotic treatment, dressing), as well as general measures (sedation, antitetanous and antibiotic protection, preoperative evaluation and correction of malnutrition, vasoconstriction, hyperglycemia and steroid use, appropriate surgical technique, and postoperative prevention of vasoconstriction through pain relief, warming and adequate volume resuscitation). ⋯ Growth factors play a role in cell division, migration, differentiation, protein expression, enzyme production and have a potential ability to heal wounds by stimulating angiogenesis and cellular proliferation, affecting the production and the degradation of the extracellular matrix, and by being chemotactic for inflammatory cells and fibroblasts. There are seven major families of growth factors: epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), interleukins (ILs), and colony-stimulating factor (CSF). Acute wounds contain many growth factors that play a crucial role in the initial phases of wound healing. The events of early wound healing reflect a finely balanced environment leading to uncomplicated and rapid wound healing. Chronic wounds, for many reasons, have lost this fine balance. Multiple studies have evaluated the effect that exogenously applied growth factors have on the healing of chronic wounds. In the study conducted by Knighton and colleagues, topical application of mixture of various growth factors (PDGF, TGF-beta, PDAF, PF4, PDEGF) demonstrated increased wound healing over controls. Brown and associates demonstrated a decrease in skin graft donor site healing time of 1 day using topically applied EGF. Herndon and ass. used systemic growth hormone in burned children and reduction in healing time made a significant clinical difference by allowing earlier wound coverage and decreasing the duration of hospitalization. The TGF family of growth factors is believed to be primarily responsible for excessive scar formation, especially the beta 1 and beta 2 isoforms. TGF-beta 3 isoform has recently been described and may have an inhibitory function on scar formation by being a natural antagonist to the TGF-beta 1 and TGF-beta 2 isoforms. Cytokines, especially interferon-alpha (INF-alpha), INF-alpha, and INF-alpha 2b, may also reduce scar formation. These cytokines decrease the proliferation rate of fibroblasts and reduce the rate of collagen and fibronectin synthesis by reducing the production of mRNA. Expression of nitric oxide synthase (NOS) and heat shock proteins (HSP) have an important role in wound healing, as well as trace elements (zinc, copper, manganese). Applications of some drugs (antioxidants--asiaticoside, vitamin E and ascorbic acid; calcium D-pantothenate, exogenous fibronectin; antileprosy drugs--oil of hydnocarpus; alcoholic extract of yeast) accelerate wound healing. Thymic peptide thymosin beta 4 (T beta 4R) topically applicated, increases collagen deposition and angiogenesis and stimulates keratinocyte migration. Thymosin alpha 1 (T alpha 1R), peptide isolated from the thymus, is a potent chemoattractant which accelerates angiogenesis and wound healing. On the contrary, steroid drugs, hemorrhage and denervation of wounds have negative effect on the healing process.
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Cataract extraction in children has improved and became more popular over the past few decades but, due to particular features of children's eyes, still remains controversial--especially regarding the intraocular lens implantation. ⋯ The functional results after pediatric cataract surgery depend not only on the anatomic success of the operation and postoperative maintenance of a clear optical axis, but even more on aphakic visual rehabilitation. Children's eyes with cataract severe enough to require cataract extraction usually have some degree of amblyopia already present prior to surgery. In unilateral pseudophakia amblyopia develops postoperatively unless the fellow eye is occluded or optically and/or pharmacologically penalized. Immediate optical correction is desirable because prevention and/or therapy of amblyopia should be initiated directly after surgery. Parental compliance with occlusion therapy and not successful surgery are major determinants of a good visual outcome in unilateral aphakic/pseudophakic children.
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Congenital adrenal hyperplasia is generally considered to be a rare disease; however, the incidence of severe forms of CAH is probably greater than 1 in 10,000 people and the incidence of milder forms is probably 10 times higher. It is a group of autosomal recessive disorders of adrenal steroidogenesis caused by a genetic disorder in one of the steroidogenic enzymes. These disorders impair cortisol synthesis, resulting in stimulation of pituitary proopiomelanocortin and hypersecretion of adrenocorticotropin, which in turn causes adrenal growth. ⋯ In "classic" form, affected newborns present with symptoms and sings of adrenal insufficiency of varying degree and ambiguous genitalia in both sexes. The "late onset" form is a mild type of disorder. It has been described in women with hirsutism and menstrual abnormalities and may be quite common. (ABSTRACT TRUN
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This paper deals with basic rational antiepileptic therapeutic procedures in children with special consideration of numerous specificities which occur in childhood: difficulties in establishing correct syndrome diagnosis, predominantly after the first or first few seizures which makes it difficult to decide about appropriate syndrome-specific therapy in regard to efficacy, mechanism of action and range of antiepileptic action; difficulties in assessment of subjective factors (their adverse effects and recognition of seizures with subjective symptoms), children's vulnerability in regard to drug toxicity; age-specific pharmacokinetics of these drugs. ⋯ Only a complex approach to child suffering from epilepsy may provide optimal development, quality of life improvement and complete social integration. Rational therapy of epilepsy in children requires good knowledge not only of age-specific syndromes, clinical pharmacology of anticonvulsants, their efficacy and range of action, but also specificity of their metabolism in children, profile of adverse effects as well as facing numerous nonmedical problems.