By C. Silas. California State University, Bakersfield. 2018.
The intravenous infusion of 5% glucose (5 g of glucose per 100 mL of solution) discount nimotop 30mg fast delivery, which had been started earlier buy nimotop 30 mg cheap, was increased to 10% cheap nimotop 30mg fast delivery. In addition discount nimotop 30 mg free shipping, 50 g glucose was given over 30 seconds through the intravenous tubing. STRUCTURE OF GLYCOGEN Muscle Glycogen, the storage form of glucose, is a branched glucose polysaccharide com- Glycogen posed of chains of glucosyl units linked by -1,4 bonds with -1,6 branches every 8 to 10 residues (see Fig. In a molecule of this highly branched structure, Glucose–1–P only one glucosyl residue has an anomeric carbon that is not linked to another glu- cose residue. This anomeric carbon at the beginning of the chain is attached to the protein glycogenin. The other ends of the chains are called nonreducing ends (see Glucose–6–P Chapter 5). The branched structure permits rapid degradation and rapid synthesis Glycolysis of glycogen because enzymes can work on several chains simultaneously from the multiple nonreducing ends. ATP Lactate Glycogen is present in tissues as polymers of very high molecular weight 7 8 CO2 (10 –10 ) collected together in glycogen particles. The enzymes involved in glyco- gen synthesis and degradation, and some of the regulatory enzymes, are bound to the surface of the glycogen particles. FUNCTION OF GLYCOGEN IN SKELETAL MUSCLE AND LIVER Glycogen Glycogen is found in most cell types, where it serves as a reservoir of glucosyl Liver units for ATP generation from glycolysis. Glucose–1–P Glycogen is degraded mainly to glucose 1-phosphate, which is converted to glu- cose 6-phosphate. In skeletal muscle and other cell types, the glucose 6-phosphate Glucose–6–P enters the glycolytic pathway (Fig. Glycogen is an extremely important fuel glucose 6glucose 6––phosphatasephosphatase source for skeletal muscle when ATP demands are high and when glucose 6-phos- Gluconeo- Glucose phate is used rapidly in anaerobic glycolysis. In many other cell types, the small genesis glycogen reservoir serves a similar purpose; it is an emergency fuel source that Blood Glucose supplies glucose for the generation of ATP in the absence of oxygen or during restricted blood flow. In general, glycogenolysis and glycolysis are activated Fig. Glycogenolysis in skeletal muscle together in these cells. Glycogen stores serve different func- Glycogen serves a very different purpose in liver than in skeletal muscle and other tions in muscle cells and liver. Liver glycogen is the first and immediate source of glucose and most other cell types, glycogen stores for the maintenance of blood glucose levels. In the liver, the glucose 6-phosphate that serve as a fuel source for the generation of is generated from glycogen degradation is hydrolyzed to glucose by glucose 6-phos- ATP. In the liver, glycogen stores serve as a phatase, an enzyme present only in the liver and kidneys. Futile cycling refers coneogenesis, the synthesis of glucose from amino acids and other gluconeogenic pre- to a situation in which a substrate is con- cursors (discussed in detail in Chapter 31), also forms glucose 6-phosphate, so that glu- verted to a product through one pathway, cose 6-phosphatase serves as a “gateway” to the blood for both pathways (see Fig. Because the biosynthetic pathway is energy-requir- III. SYNTHESIS AND DEGRADATION OF GLYCOGEN ing, futile cycling results in a waste of high- energy phosphate bonds. Thus, glycogen Glycogen synthesis, like almost all the pathways of glucose metabolism, begins synthesis is activated when glycogen degra- with the phosphorylation of glucose to glucose 6-phosphate by hexokinase or, in the dation is inhibited, and vice versa. Glucose 6-phosphate is the precursor of glycolysis, the pentose phosphate pathway, and of pathways for the synthesis of other sugars. In the pathway for glycogen synthesis, glucose 6-phosphate is converted to glucose 1-phosphate by phosphoglucomutase, a reversible reaction. Glycogen is both formed from and degraded to glucose 1-phosphate, but the biosynthetic and degradative pathways are separate and involve different enzymes (see Fig.
There remain disagreements among authors on the need for bracing nimotop 30mg on line, brace type and duration of use (when used) discount 30mg nimotop mastercard, and the diagnostic evaluation necessary before the initiation of treatment nimotop 30mg low price. The largest series published is 14 that of d’Hemecourt et al buy 30mg nimotop amex. The authors retrospectively assessed 73 adolescent athletes who had been treated with a Boston Overlap Brace for the diagnosis of spondylolysis. The diagnosis was established by the use of plain radiographs, nuclear imaging (bone scan with SPECT), and CT if no fracture was visible on plain films. As the authors note that 14 of the 73 patients had negative “bone scans” and all 73 patients had CT scans, it is uncertain what the “gold standard” for establishing the diagnosis was, however. The patients in this study were advised to wear their orthosis 23 hours per day for 6 months with a weaning period of several months. Physical therapy emphasizing a flexion bias was also provided, and athletes were allowed to return to sport at 4–6 weeks if they had no pain with extension provided that they wore the brace and remained pain free. The authors noted several predictors of poor outcome, including being female and participating in “high risk” sports, such as gymnastics, dance, soccer, and football. The lack of controls, retrospective design, limited data on outcomes, and unclear diagnostic criteria are all significant limitations of this study. Conclusions Overall, there has been no data published to alter our recommendations for diagnosis and treatment from those in the original publication of Evidence-based Sports 1,2 Medicine. As before, there remains a substantial need for controlled trials of different treatment methods (for example, relative rest with or without a brace) and for studies that directly compare the relative sensitivity and specificity of different imaging modalities, especially for SPECT v MRI. Until these are available, a rational approach to treatment will have to be based upon a thorough understanding of all the available science on the natural history, pathogenesis, diagnosis, and treatment of spondylolysis. The prevalence of spondylolysis and spondylolisthesis in symptomatic elite athletes: radiographic findings. Back injuries in young fast bowlers—a radiologic investigation of the healing of spondylolysis and pedicle sclerosis. Hollenberg GM, Beattie PF, Meyers SP, Weinberg EP, Adams MJ. Stress reactions of the lumbar pars interarticularis. Lighting up spondylolysis to identify stress fractures with the capacity for healing. Hollenberg GM, Beitia AO, Tan RK, Weinberg EP, Adams MJ. Spondylolysis and spondylolisthesis in the child and adolescent athlete. Spondylolysis and spondylolisthesis in the pediatric and adolescent population. Current evaluation and management of spondylolysis and spondylolisthesis. Spondylolysis: Returning the athlete to sports participation with brace treatment. Sys J, Michielsen J, Bracke P, Martens M, Verstreken J. Nonoperative treatment of active spondylolysis in elite athletes with normal X-ray findings: literature review and results of conservative treatment. Update for Chapter 16: Are corticosteroid injections as effective as physiotherapy for the treatment of a painful shoulder? Koes, PhD Professor of General Practice Faculty of Medicine and Health Sciences, Department of General Practice Erasmus University Rotterdam, The Netherlands Are corticosteroid injections as effective as physiotherapy for the treatment of a painful shoulder? Introduction In this review we systematically summarize the available evidence on the effectiveness of physiotherapy and corticosteroid injections for shoulder pain. The review is an update of Chapter 16 of Evidence-based Sports Medicine. For the update of this review the search was extended to include the period January 2001 to October 2003, using the same keywords and selection criteria. Quality assessment The internal validity of each trial was scored by two reviewers independently, using the validity criteria of the Amsterdam-Maastricht Consensus List for Quality Assessment. Data extraction and analysis Details on selection criteria, interventions, outcome assessment, adverse reactions, and results were extracted for each trial.
Siegfried and Lippitz were among the ﬁrst to report the use of DBS for continuously stimulating the ventroposterolateral pallidum purchase 30 mg nimotop with mastercard. They implanted bilateral GPi electrodes in three PD patients discount 30 mg nimotop visa. Follow-up in these three patients ranged from 3 months to 1 year discount 30mg nimotop with amex. They reported improvement in Webster Rating Scale scores and on-off motor ﬂuctuations cheap nimotop 30 mg free shipping. Since then, multiple studies have reported the efﬁcacy of GPi stimulation for PD (see Table 2). All studies reported a small number of patients, and follow-up has ranged from days to a maximum of 30 months. The patients have been implanted unilaterally and bilaterally. The improvement in the off medication state in activities of daily living ranged from 19 to 68%, and the UPDRS Motor score improvement ranged from 24 to 50%. The improvement in activities of daily living in the on medication state ranged from 22 to 60%, and UPDRS Motor scores ranged from 1 to 60%. All studies reported signiﬁcant reductions in dyskinesias, resulting in improvement in on time during the day. Three patients had bilateral implants, and two had unilateral implants. Four patients were markedly improved, and one was moderately improved after surgery. The activities of daily living subscores of the UPDRS improved by 19% in the off-medication state and by 42% in the on- TABLE 2 Selected Studies of Deep Brain Stimulation of the Globus Pallidus Author Number of patients Follow-up UPDRS improvement Pahwa et al. Patient diaries demonstrated an increase in on-time with a decrease in both off-time and on-time with dyskinesias. A review by the American Academy of Neurology identiﬁed reports on 64 patients who had undergone DBS of the globus pallidus (23). An approximately equal number of patients underwent unilateral and bilateral implantations. Beneﬁt was reported in all aspects of PD with a marked attenuation of motor ﬂuctuations and dyskinesias. In unilateral implants, the beneﬁts were most pronounced on the contralateral side. Evaluations performed in the off-medication state at 6 months reported a 32% improvement in UPDRS motor scores, 40% improvement in UPDRS activities of daily living scores, and 23% improvement in dyskinesias. When the evaluations were repeated in the medication ‘‘on state,’’ UPDRS motor scores improved by 1%, UPDRS activities of daily living scores improved by 30%, and dyskinesias improved by 68%. The Deep Brain Stimulation for Parkinson’s Disease Study Group reported a multinational, prospective study of bilateral GPi stimulation in PD (25). Forty-one patients were enrolled; electrodes were implanted in 38 patients (two patients had cerebral hemorrhage and one patient had intraoperative confusion). In comparison to baseline, there was a signiﬁcant improvement in the UPDRS motor scores in the off-medication state and a smaller improvement in the on-medication state. In the off-medication state, all the subscales of the UPDRS also improved. Tremor scores improved by 59%, rigidity improved by 31%, bradykinesia improved by 26%, gait by 35%, and postural instability by 36%. In the on-medication state, tremor scores improved by 85%, rigidity and bradykinesia by 22%, gait by 33%, and postural instability by 50%. Patient diaries revealed that the percentage of on time without dyskinesias during the awake time increased from 28 to 64%, and the off time reduced from 37 to 24%. The mean daily dose in levodopa equivalents was unchanged between baseline and 6 months. Long-term results of DBS of the globus pallidus have been lacking. The mean improvement in the UPDRS motor ‘‘off’’ scores and the ADL scores was more than 50%.
Factor XIII cross-links strands of polymerized fibrin monomers to form a stable clot (the secondary hemostatic plug) cheap 30 mg nimotop overnight delivery. The blood coagulation cascade consists of a series of enzymes (such as Factor X) purchase nimotop 30mg without a prescription, which are inactive until proteolytically cleaved by the preceding enzyme in the cascade buy 30 mg nimotop otc. Other proteins (Factor V and Factor VIII) serve as bind- ing proteins cheap nimotop 30 mg on-line, which assemble factor complexes at the site of injury. Ca 2+ and - carboxyglutamate residues in the proteins (formed by a vitamin K–dependent process in the liver) attach the factor complexes to phospholipids exposed on platelet membranes. Consequently, thrombus formation is rapidly accelerated and localized to the site of injury. Regulatory mechanisms within the blood coagulation cascade and antifibri- nolytic mechanisms prevent random coagulation within blood vessels that might obstruct blood flow. An x-ray showed no fractures, but a soft tissue swelling, consistent with a hematoma (bleeding into the tissues), was noted. Sloe’s mother related that soon after he began to crawl, his knees occasionally became swollen and seemed painful. The pediatrician suspected a disorder of coagulation. A screening coagulation profile suggested a possible deficiency of Factor VIII, a protein involved in the for- mation of blood clots. Sloe’s plasma Factor VIII level was found to be only 3% of the average level found in normal subjects. PLASMA PROTEINS MAINTAIN PROPER DISTRIBUTION OF WATER BETWEEN BLOOD AND TISSUES When the cells are removed from the blood, the remaining plasma is composed of water, nutrients, metabolites, hormones, electrolytes, and proteins. Plasma has essentially the same electrolyte composition as other extracellular fluids and con- stitutes approximately 25% of the body’s total extracellular fluid. The plasma pro- teins serve a number of functions, which include maintaining the proper distribution of water between the blood and the tissues, transporting nutrients, metabolites, and hormones throughout the body, defending against infection, and maintaining the integrity of the circulation through clotting. Many diseases alter the amounts of plasma proteins produced and, hence, their concentration in the blood. These The hydrostatic pressure in an changes can be determined by electrophoresis of plasma proteins over the course of arteriole is the force that “pushes” a disease. Body Fluid Maintenance between Tissues and Blood osmotic pressure, plus the tissue pressure, is the force that “pulls” water from intersti- As the arterial blood enters the capillaries, fluid moves from the intravascular space tial spaces into the venular side of the capil- into the interstitial space (that surrounding the capillaries) because of what are lary. Thus, if the hydrostatic pressure is known as Starling’s forces. The hydrostatic pressure in the arteriolar end of the cap- greater than the osmotic pressure, fluid will illaries (~37 mm Hg) exceeds the sum of the tissue pressure (~1 mm Hg) and the leave the circulation; if it is less, fluid will osmotic pressure of the plasma proteins (~25 mm Hg). At the venous end of the capillaries, the hydrostatic pressure falls to approximately 17 mm Hg while the osmotic pres- In cases of severe protein malnutri- sure and the tissue pressure remain constant, resulting in movement of fluid back tion (kwashiorkor), the concentra- from the extravascular (interstitial) spaces and into the blood. Thus, most of the tion of the plasma proteins decreases, as a result of which the osmotic force bringing water back from the tissues is the osmotic pressure mediated by the pressure of the blood decreases. The distended bellies of famine vic- As indicated in Table 45. The major protein synthesized is albumin, the extravascular tissues because of the severely decreased concentration of plasma which constitutes approximately 60% of the total plasma protein, but because of its proteins, particularly albumin. Albumin syn- relatively small size (69 kDa) is thought to contribute 70 to 80% of the total osmotic thesis decreases fairly early under condi- pressure of the plasma. Albumin, like most plasma proteins, is a glycoprotein and is tions of protein malnutrition. CHAPTER 45 / BLOOD PLASMA PROTEINS, COAGULATION AND FIBRINOLYSIS 829 Table 45. Specific Plasma Binding Proteins Synthesized in the Liver Ceruloplasmin Binds copper; appears to be more important as a copper storage pool than as a transport protein; integrates iron and copper homeostasis Corticosteroid-binding globulin Binds cortisol Haptoglobin Binds extracorpuscular heme Lipoproteins Transport cholesterol and fatty acids Retinol-binding protein Binds vitamin A Sex hormone–binding globulin Binds estradiol and testosterone Transferrin Transports iron Transthyretin Binds thyroxine (T4); also forms a complex with retinol- binding protein Many drugs also bind to albumin, which may have important pharmacologic impli- In spite of the importance of albu- cations. For example, when a drug binds to albumin, such binding will likely lower min in the maintenance of osmotic pressure in the blood, individuals the effective concentration of that drug and may lengthen its lifetime in the circula- lacking albumin (analbuminemia) have only tion. Drug dosimetry may need to be recalculated if a patient’s plasma protein con- moderate edema. The fre- quency of analbuminemia is less than one II.
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