By B. Benito. Blue Mountain College.
The thigh–foot alignment gives a measurement of the overall alignment of the leg and foot discount viagra professional 50 mg with mastercard. A more specific measurement of tibial torsion is measuring the transmalle- olar to thigh angle 50 mg viagra professional fast delivery. This age is also when a standing program should be started. Most children should be followed every 6 months for a musculoskeletal evaluation. By the time these children have scoliosis corrected at puberty, much less change occurs over time and the follow-up can be lengthened, often to 1 year or more. Usually, solid ankle-foot orthoses (AFOs) are fitted at approximately 24 months of age so weight bearing in a stander, with a goal of standing for at least 1 hour per day, can begin. Children with adequate motor control of their head should be started in a prone stander, and those who do not have good head control should be placed in a supine stander. As these children enter late childhood to prepuberty, scoliosis becomes the main concern. As these children go through puberty, their increased height and weight often make their care much more difficult for caretakers, causing anxiety about how they will be cared for as they become full adult size. This issue should be addressed by a social worker familiar with state laws and avail- able resources. Because of multiple medical problems and total custodial care requirements, the parents or caretakers often have significant periods of stress or just fatigue. Parents should be educated on the available options, espe- cially what options they have if they get to the point where they acutely can- not cope with their growing child. If available, this resource should ideally be through a prearranged respite care provider, but few of these are avail- able. The only option may be the hospital; however, it often helps the parents just to know what their options are. The problems the caretakers focus on may not be the problems the physi- cian focuses on, and often they are diametrically opposed. Nutrition and feeding are areas physicians are often concerned with, especially when a child is very small and malnourished; however, from the parents’ perspective, oral feeding of the child may be the most positive interactive experience the child and parent have. Also, the parents may be happy for the child to stay small, so that they are easier to lift and transfer. For these reasons, parents may re- sist interventions, such as gastrostomy tubes, to make the child grow heavier and make feeding easier, all of which would be very positive from the physi- cian’s perspective. Feeding, Growth, and Weight Problems A major problem for many children with CP is poor nutrition. Many pri- mary care physicians in the community do not have the physical equipment in their offices to weigh and measure children who cannot walk, and many do not have a good knowledge base or an available nutritionist to help them assess current food intake or dietary needs. Part of the evaluation in a CP clinic should be to measure the height and weight of these children. Weight is easy to get with an appropriate scale, which should always be available in this type of clinic environment. Height measurement is more difficult and less reliable for individuals who cannot stand. If scoliosis is present, stand- ing height is also not reliable. In these children, armspan measurement, which needs no conversion if children are able to fully abduct the shoulders and extend the elbows, wrists, and fingers, should be used. However, for many children with CP, this abduction and extension is not possible and there are several other measures for doing segmental heights. The forearm ruler is calibrated in such a way that the elbow is flexed 90° and the hands and fingers are extended (A). The patterns of involvement will not be growing at a normal rate and may have 4 height can then be read at the tip of the long quite abnormal caloric needs. Most children should gain some weight from finger (B). This ruler is easy to use, requires 1 year to the next during childhood. If not, a nutritional assessment should no conversion math, and allows the height to be considered by evaluating the nutritional intake through a formal calorie be plotted on a standard growth chart. This count and, in some cases, measuring the caloric requirement. Children over age 2 years, other measures of height. Gingival hyperplasia is widely blamed on antiepileptic medications, especially Dilantin5; however, this prob- lem is widespread in children with oral motor problems because of poor clearance of saliva. This gingivitis needs good dental care and treatment to prevent dental caries, which are also more common in children with abnor- mal motor function. The bones tend to be thin with an overall decreased bone mass, called osteoporosis, and a decreased bone mineral den- sity, described as osteomalacia. The cause of poor bone formation is multi- factorial and occurs primarily in nonambulatory children because bones do not develop normal strength and size unless a normal amount of stress is applied to them. The diameter of the tubular bones, such as the femur, and the bone’s cortical width largely grow to their determined size based on the stress the bone experiences during growth. The exact required amount and nature of this stress is unknown, but it probably requires a combination of maximal compressive and torsional stress as well as a stress-time history. Bones need to have a stress of approximately one to two times body weight applied at least a certain number of times every day. Also, bones need to ex- perience at least body weight for a certain number of hours, such as 3 hours, in every 24-hour period.
She was continued in her physical therapy trauma of the surgery trusted viagra professional 100mg, neither she nor her mother was program to work on balance and motor control issues purchase viagra professional 50mg amex. This case is also a good example of She continued to make good progress until age 6 years, a family that is happy because of the excellent gains, even when she plateaued in her motor skills development. At though the surgeon would grade this outcome as dis- that time she had a full evaluation. On physical exami- appointing because of the severe stiff knee gait, which nation she was noted to have hip abduction of 25°, and should have been treated at the initial procedure. Hip external rotation was 5° on the right and 12° on the left. Popliteal angles were 65° on the right and 73° on the left. Extended knee ankle dorsiflexion was −8° on the right and −10° on the left. Flexed knee ankle dorsiflexion was 5° on the right and 3° on the left. Observation of her gait demonstrated that she was efficient in ambulating with a posterior walker. However, she had severe internal rotation of the hips, with knee flexion at foot contact and in midstance, and a toe strike without getting flat foot at any time. The kinematics confirmed the same and the EMG showed sig- nificant activity in swing phase of the rectus muscles. There was minimal motion at the knee with ankle equi- nus and lack of hip extension and internal rotation of the hip (Figure C7. She had femoral derotation osteo- tomies, distal hamstring lengthenings, and gastrocnemius lengthenings. A rectus transfer was also recommended, but because of the fear of causing further crouch, she did Figure C7. Another error is in not considering the energy cost of walking. Children who use 2 ml oxygen per kilogram per meter walking are not going to be com- munity ambulators, and judgment has to be directed as to their real function, which will primarily be sitting in a wheelchair. Also, children’s general con- dition should be considered as the complaints related to walking may be in part result from very poor conditioning and not specific deformities. Interrelated Effect of Multiple Procedures When interpreting gait data, there should be an awareness of the impact of adding procedures together. Most procedures are relatively independent of each other; however, there are some interactions. Understanding the impact of multiple concurrent procedures is somewhat like understanding drug inter- 7. Some specific combinations to watch out for include tibial derotation for internal tibial torsion in the ipsilateral side of a foot that is having pos- terior tibial tendon surgery for equinovarus. In a small series of 10 limbs, 8 failed and required repeat surgery, all with overcorrection. Another procedure interaction is planovalgus foot correc- tion so that the heel is in neutral through the use of a subtalar fusion, then doing a supramalleolar osteotomy to correct ankle valgus. This combination of procedures will leave the heel with a residual varus deformity, which is highly undesirable. Another interaction of procedures is that patients who have external tibial torsion that is not being corrected should not have only medial hamstring lengthening, as this will further imbalance the external rotation torque by allowing the biceps femoris muscle to create additional external torque through the knee joint. Complications of Surgical Execution The most common complication of surgical execution is overcorrection of a deformity, especially in correction of femoral anteversion. The reason undercorrection occurs is that the femur is somewhat square, and often the plate used for fixation wants to set on the corner, but as the screws are tightened, it may rotate 10° or 15° in one direction or the other. Careful intraoperative evaluation after the fixation is important, and if the rotation is not corrected, it can be corrected immedi- ately. Other intraoperative problems are specific to the procedure, such as rec- ognizing that the foot will never look better than it does immediately after the surgery has been performed in the operating room; therefore, if the foot is still in valgus, it will be so when the cast is removed. Three months and 12 months after surgery, this valgus will only get worse, not better. Correcting residual problems in the operating room is much easier than deciding to come back and correct them with a separate surgical procedure or a revision procedure. Complications of Rehabilitation The major problem with rehabilitation is the lack of follow-through by fam- ilies, or failure of families to be able to pay or get their insurance companies to pay for the therapy that is required. Most children can be rehabilitated as outpatients; however, there are a few especially complicated cases that really benefit from inpatient rehabilitation. The need for postoperative rehabilita- tion should be discussed with families, and an understanding of how and who will provide this is important even before undertaking the surgery. It is important to have therapists who clearly understand the goals for these chil- dren’s function, as it is of little benefit to have therapists spend a great deal of time working on sitting transfers when the goal of the surgery was to get the children walking. Postoperatively, the physical therapy has to be directed at the goal that was preoperatively defined through communication with the surgeon, who should be able to clearly articulate what the goals of the sur- gery were. Other issues in the postoperative period that may cause problems are postoperative pain and subsequent depression. Postoperative pain and de- pression need to be treated aggressively if they are interfering with the ability of patients to cooperate with the rehabilitation program.
The carbons for cysteine synthesis come from glucose discount 100 mg viagra professional free shipping; the methionine only donates the sulfur cheap viagra professional 50 mg. The carbon skeletons of the 10 nonessential amino acids derived from glucose are produced from intermediates of glycolysis and the tricarboxylic acid (TCA) cycle (see Fig 39. Four amino acids (serine, glycine, cysteine, and alanine) are produced from glucose through components of the glycolytic pathway. TCA cycle intermediates (which can be produced from glucose) provide carbon for synthesis of the six remaining nonessential amino acids. Oxaloacetate pro- vides carbon for the synthesis of aspartate and asparagine. The regulation of individual amino acid biosynthesis can be quite complex, but the overriding feature is that the pathways are feedback regulated such that as the concentration of free amino acid increases, a key biosynthetic enzyme is allosterically or transcriptionally inhibited. Amino acid levels, however, are 712 CHAPTER 39 / SYNTHESIS AND DEGRADATION OF AMINO ACIDS 713 Glucose Glycine Phosphoglycerate Methionine (S) Asparagine Serine Cysteine TA Pyruvate Alanine Glutamine TA Aspartate Oxaloacetate Acetyl CoA Phenylalanine Tyrosine Citrate Glutamine Isocitrate TA α–Ketoglutarate Glutamate Glutamate semialdehyde GDH Proline Arginine Fig. Overview of the synthesis of the nonessential amino acids. The carbons of 10 amino acids may be produced from glucose through intermediates of glycolysis or the TCA cycle. The 11th nonessential amino acid, tyrosine, is synthesized by hydroxylation of the essential amino acid phenylalanine. Only the sulfur of cysteine comes from the essential amino acid methionine; its carbons and nitrogen come from serine. Transamination (TA) reactions involve pyridoxal phosphate (PLP) and another amino acid/ -keto acid pair. Degradation of amino acids: The degradation pathways for amino acids are, in general, distinct from biosynthetic pathways. This allows for separate regulation of the anabolic and catabolic pathways. Because protein is a fuel, almost every amino acid will have a degradative pathway that can generate NADH, which is used as an electron source for oxidative phosphorylation. However, the energy- generating pathway may involve direct oxidation, oxidation in the TCA cycle, con- version to glucose and then oxidation, or conversion to ketone bodies, which are then oxidized. The fate of the carbons of the amino acids depends on the physiologic state of the individual and the tissue where the degradation occurs. For example, in the liver during fasting, the carbon skeletons of the amino acids produce glucose, ketone bodies, and CO2. In the fed state, the liver can convert intermediates of amino acid metabolism to glycogen and triacylglycerols. Thus, the fate of the car- bons of the amino acids parallels that of glucose and fatty acids. The liver is the only tissue that has all of the pathways of amino acid synthesis and degradation. As amino acids are degraded, their carbons are converted to (a) CO2, (b) com- pounds that produce glucose in the liver (pyruvate and the TCA cycle intermedi- ates -ketoglutarate, succinyl CoA, fumarate, and oxaloacetate), and (c) ketone bodies or their precursors (acetoacetate and acetyl CoA) (Fig. For simplic- ity, amino acids are considered to be glucogenic if their carbon skeletons can be converted to a precursor of glucose and ketogenic if their carbon skeletons can be directly converted to acetyl CoA or acetoacetate. Some amino acids contain car- bons that produce a glucose precursor and other carbons that produce acetyl CoA or acetoacetate. These amino acids are both glucogenic and ketogenic. The amino acids synthesized from intermediates of glycolysis (serine, alanine, and cysteine) plus certain other amino acids (threonine, glycine, and tryptophan) 714 SECTION SEVEN / NITROGEN METABOLISM A Tryptophan Alanine Alanine Blood Serine Threonine Glycine Cysteine Pyruvate Acetyl CoA Arginine Histidine Oxaloacetate Glutamine Muscle Aspartate Proline Gut Asparagine Kidney Glutamate TCA Liver cycle Glucose Malate α–Ketoglutarate Fumarate Succinyl CoA Aspartate Tyrosine Phenylanine Methylmalonyl CoA Valine Threonine Isoleucine Propionyl CoA Methionine B Leucine Acetyl CoA + Acetoacetyl CoA HMG CoA Acetoacetate Threonine (ketone bodies) Lysine Isoleucine Tryptophan Phenylalanine, Tyrosine Fig. Amino acids that produce pyruvate or intermediates of the TCA cycle. These amino acids are consid- ered glucogenic because they can produce glucose in the liver. The fumarate group of amino acids produces cytoplasmic fumarate. Potential mechanisms whereby the cytoplasmic fumarate can be oxidized are presented in section III. Amino acids that produce acetyl CoA or ketone bodies. The amino acids synthesized from TCA cycle intermediates (aspartate, asparagines, glutamate, glutamine, proline, and arginine) are reconverted to these intermediates during degradation. Histidine is converted to glutamate and then to the TCA cycle intermediate -ketoglutarate. Methionine, threonine, valine, and isoleucine form succinyl CoA, and pheny- lalanine (after conversion to tyrosine) forms fumarate. Because pyruvate and the TCA cycle intermediates can produce glucose in the liver, these amino acids are glucogenic. Some amino acids with carbons that produce glucose also contain other car- bons that produce ketone bodies. Tryptophan, isoleucine, and threonine produce acetyl CoA, and phenylalanine and tyrosine produce acetoacetate. These amino acids are both glucogenic and ketogenic. Two of the essential amino acids (lysine and leucine) are strictly ketogenic. They do not produce glucose, only acetoacetate and acetyl-CoA. CHAPTER 39 / SYNTHESIS AND DEGRADATION OF AMINO ACIDS 715 THE WAITING ROOM Piquet Yuria, a 4-month-old female infant, emigrated from the Soviet Union with her French mother and Russian father 1 month ago. She was normal at birth but in the last several weeks was less than normally attentive to her surroundings.
On examining the gel himself discount 50mg viagra professional overnight delivery, the husband became concerned that he might not be the biologic father of one or both of the children cheap viagra professional 100 mg without prescription. From the pattern on the gel, you can reasonably conclude which of the following? An alcoholic is brought to the Emergency Room for a hypoglycemic coma. Because alcoholics are frequently malnourished, which of the following enzymes can be used to test for a thiamine deficiency? Intravenous fructose feeding can lead to lactic acidosis caused by which of the following? The polyol pathway of sorbitol production and the HMP shunt pathway are linked by which of the following? The pathways for oxidation of fatty acids, Krebs first formulated its reactions glucose, amino acids, acetate, and ketone bodies all generate acetyl CoA, into a cycle. It is also called the “citric acid which is the substrate for the TCA cycle. As the activated 2-carbon acetyl cycle” because citrate was one of the first group is oxidized to two molecules of CO2, energy is conserved as NADH, compounds known to participate. The most common name for this pathway, the tricar- FAD(2H), and GTP (Fig. NADH and FAD(2H) subsequently donate boxylic acid or TCA cycle, denotes the electrons to O2 via the electron transport chain, with the generation of ATP involvement of the tricarboxylates citrate from oxidative phosphorylation. Thus, the TCA cycle is central to energy gen- and isocitrate. Within the TCA cycle, the oxidative decarboxylation of -ketoglutarate is cat- The major pathways of fuel oxida- alyzed by the multisubunit -ketoglutarate dehydrogenase complex, which con- tion generate acetyl CoA, which is tains the coenzymes thiamine-pyrophosphate, lipoate, and FAD. In plex, the pyruvate dehydrogenase complex (PDC), catalyzes the oxidation of the first step of the TCA cycle, the acetyl por- pyruvate to acetyl CoA, thereby providing a link between the pathways of glycoly- tion of acetyl CoA combines with the 4- sis and the TCA cycle (see Fig. In the next two oxidative transferred to NAD and FAD and also the carbon in the two CO2 molecules that decarboxylation reactions, electrons are are produced. Oxaloacetate is used and regenerated in each turn of the cycle (see transferred to NAD to form NADH, and 2 Fig. However, when cells use intermediates of the TCA cycle for molecules of electron-depleted CO2 are released. Subsequently, a high- energy phosphate bond in GTP is generated from Glucose Fatty acids substrate level phosphorylation. In the Pyruvate remaining portion of the TCA cycle, succi- Ketone bodies nate is oxidized to oxaloacetate with the generation of one FAD(2H) and one NADH. CO2 The net reaction of the TCA cycle, which is the sum of the equations for individual Acetate Acetyl CoA Amino acids steps, shows that the two carbons of the CoASH acetyl group have been oxidized to two mol- OxaloacetateOxaloacetate + (4c)(4c) ecules of CO2, with conservation of energy NADH + H Citrate (6c)Citrate (6c) as three molecules of NADH, one of Malate (4c)Malate (4c) Isocitrate (6c)Isocitrate (6c) FAD(2H), and one of GTP. Fumarate (4c)Fumarate (4c) Tricarboxylic acid NADH + H+ FAD (2H) (TCA) cycle Succinate (4c)Succinate (4c) CO 2 αα-Ketoglutarate (5c)-Ketoglutarate (5c) GTP Succinyl-Succinyl- NADH + H+ GDP CoACoA (4c) CO2 Net reaction Acetyl CoA + 3NAD+ + FAD 2CO + CoASH + 3NADH + 3H+ 2 + GDP + P + 2Hi 2O + FAD (2H) + GTP Fig. The TCA cycle occurs in the mitochondrion, where its flux is tightly coordi- nated with the rate of the electron transport chain and oxidative phosphorylation through feedback regulation that reflects the demand for ATP. The rate of the TCA cycle is increased when ATP utilization in the cell is increased through the response of several enzymes to ADP levels, the NADH/ NAD ratio, the rate of FAD(2H) oxidation or the Ca2 concentration. For example, isocitrate dehydro- genase is allosterically activated by ADP. There are two general consequences to impaired functioning of the TCA cycle: (1) an inability to generate ATP from fuel oxidation, and (2) an accumulation of TCA cycle precursors. For example, inhibition of pyruvate oxidation in the TCA cycle results in its reduction to lactate, which can cause a lactic acidosis. The most common situation leading to an impaired function of the TCA cycle is a rela- tive lack of oxygen to accept electrons in the electron transport chain. THE WAITING ROOM Otto Shape, a 26-year-old medical student, has faithfully followed his diet and aerobic exercise program of daily tennis and jogging (see Chapter 19). He has lost a total of 33 lb and is just 23 lb from his college weight of 154 lb. His exercise capacity has markedly improved; he can run for a longer time at a Vitamins and minerals faster pace before noting shortness of breath or palpitations of his heart. Even his required for the TCA cycle test scores in his medical school classes have improved. In Riboflavin (FAD) addition to a low body weight, decreased muscle mass, glycogen, and fat Pantothenate (CoA) stores, she has iron-deficiency anemia (see Chapter 16). She has started to Thiamine gain weight, and is trying a daily exercise program. However, she constantly feels weak Biotin Mg2 and tired. On this visit to her nutri- Ca2 tionist, they discuss the vitamin content of her diet, and its role in energy metabolism. Fe2 Phosphate Al Martini has been hospitalized for congestive heart failure (see Chapter 8) and for head injuries sustained while driving under the influence of alco- hol (Chapters 9 and 10). He completed an alcohol detoxification program, O H enrolled in a local Alcoholics Anonymous (AA) group, and began seeing a psy- •• H C ••C~SCoA chologist. During this time, his alcohol-related neurologic and cardiac manifesta- •• H tions of thiamine deficiency partially cleared. However, in spite of the support he Acetyl CoA was receiving, he began drinking excessive amounts of alcohol again while eating poorly. Three weeks later, he was readmitted with symptoms of “high output” heart Fig. Acetyl CoA donates eight electrons to the TCA cycle, which are shown in blue, and two carbons. The acetyl group is the ultimate source of the carbons in the two molecules of CO2 that In the TCA cycle, the 2-carbon acetyl group of acetyl CoA is oxidized to 2 CO2 mol- are produced, and the source of electrons in the ecules (see Fig.
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