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1.
Amino Acids ; 45(5): 1133-42, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23904096

RESUMO

Exercise raises brain serotonin release and is postulated to cause fatigue in athletes; ingestion of branched-chain amino acids (BCAA), by competitively inhibiting tryptophan transport into brain, lowers brain tryptophan uptake and serotonin synthesis and release in rats, and reputedly in humans prevents exercise-induced increases in serotonin and fatigue. This latter effect in humans is disputed. But BCAA also competitively inhibit tyrosine uptake into brain, and thus catecholamine synthesis and release. Since increasing brain catecholamines enhances physical performance, BCAA ingestion could lower catecholamines, reduce performance and thus negate any serotonin-linked benefit. We therefore examined in rats whether BCAA would reduce both brain tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis. Sedentary and exercising rats received BCAA or vehicle orally; tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis rates were measured 1 h later in brain. BCAA reduced brain tryptophan and tyrosine concentrations, and serotonin and catecholamine synthesis. These reductions in tyrosine concentrations and catecholamine synthesis, but not tryptophan or serotonin synthesis, could be prevented by co-administering tyrosine with BCAA. Complete essential amino acid mixtures, used to maintain or build muscle mass, were also studied, and produced different effects on brain tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis. Since pharmacologically increasing brain catecholamine function improves physical performance, the finding that BCAA reduce catecholamine synthesis may explain why this treatment does not enhance physical performance in humans, despite reducing serotonin synthesis. If so, adding tyrosine to BCAA supplements might allow a positive action on performance to emerge.


Assuntos
Aminoácidos de Cadeia Ramificada/metabolismo , Encéfalo/metabolismo , Catecolaminas/metabolismo , Exercício Físico/fisiologia , Serotonina/metabolismo , Animais , Suplementos Nutricionais/análise , Humanos , Ratos , Ratos Sprague-Dawley
2.
J Food Eng ; 109(1): 76-86, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22523440

RESUMO

Measuring food volume (portion size) is a critical component in both clinical and research dietary studies. With the wide availability of cell phones and other camera-ready mobile devices, food pictures can be taken, stored or transmitted easily to form an image based dietary record. Although this record enables a more accurate dietary recall, a digital image of food usually cannot be used to estimate portion size directly due to the lack of information about the scale and orientation of the food within the image. The objective of this study is to investigate two novel approaches to provide the missing information, enabling food volume estimation from a single image. Both approaches are based on an elliptical reference pattern, such as the image of a circular pattern (e.g., circular plate) or a projected elliptical spotlight. Using this reference pattern and image processing techniques, the location and orientation of food objects and their volumes are calculated. Experiments were performed to validate our methods using a variety of objects, including regularly shaped objects and food samples.

3.
Neurochem Res ; 36(3): 559-65, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21207140

RESUMO

Serotonin (5HT) synthesis in brain is influenced by precursor (tryptophan (TRP)) concentrations, which are modified by food ingestion. Hence, in rats, a carbohydrate meal raises brain TRP and 5HT; a protein-containing meal does not, but little attention has focused on differences among dietary proteins. Recently, single meals containing different proteins have been shown to produce marked changes in TRP and 5HT. The present studies evaluate if such differences persist when rats ingest such diets chronically. Male rats were studied that ingested diets for 9 days containing zein, wheat gluten, soy protein, casein, or α-lactalbumin (17% dry weight). Brain TRP varied up to eightfold, and 5HT synthesis fivefold among the different protein groups. TYR and LEU concentrations, and catecholamine synthesis rate in brain varied much less. The effects of dietary protein on brain TRP and 5HT previously noted after single meals thus continue undiminished when such diets are consumed chronically.


Assuntos
Encéfalo/metabolismo , Dieta , Proteínas Alimentares/metabolismo , Serotonina/biossíntese , Triptofano/metabolismo , Animais , Peso Corporal , Leucina/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley
4.
Nutr Neurosci ; 14(6): 260-7, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22053757

RESUMO

OBJECTIVES: Previous studies have shown that brain tyrosine (TYR) levels and catecholamine synthesis rate increase in rats as chronic dietary protein content increases from 2 to 10% (% weight). A single protein, casein, was examined. The present study explores how TYR levels and catecholamine synthesis (and tryptophan (TRP) levels and serotonin synthesis) change when different proteins are ingested chronically over the same range of dietary protein contents. METHODS: Male rats ingested for 8 days diets contain 2 or 10% protein (zein, gluten, casein, soy protein, or alpha-lactalbumin). On the last day, they were killed 2.5 hours into the dark period, 30 minutes after receiving an injection of m-hydroxybenzylhydrazine, an inhibitor of aromatic l-amino acid decarboxylase. Brain samples were analyzed for amino acids, including 5-hydroxytryptophan (index of serotonin synthesis rate) and dihydroxyphenylalanine (index of catecholamine synthesis rate), by HPLC-electrochemical detection. RESULTS: TYR levels and catecholamine synthesis rate in brain were unaffected by the particular protein ingested. However, TRP levels and serotonin synthesis rate varied markedly, depending on the protein ingested, with effects being most prominent in the 10% protein groups. The effect of dietary protein on brain TRP correlated very highly with its effect on serotonin synthesis. DISCUSSION: The results indicate that the protein ingested can chronically modify TRP levels and serotonin synthesis in brain, but not TYR levels or catecholamine synthesis, with effects most distinct at an adequate level of protein intake (10%).


Assuntos
Encéfalo/metabolismo , Catecolaminas/metabolismo , Proteínas Alimentares/administração & dosagem , Serotonina/metabolismo , Triptofano/metabolismo , Tirosina/metabolismo , 5-Hidroxitriptofano/metabolismo , Animais , Inibidores das Descarboxilases de Aminoácidos Aromáticos , Encéfalo/efeitos dos fármacos , Caseínas/administração & dosagem , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Dieta com Restrição de Proteínas/efeitos adversos , Di-Hidroxifenilalanina/metabolismo , Inibidores Enzimáticos/farmacologia , Hidrazinas/farmacologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Masculino , Deficiência de Proteína/sangue , Deficiência de Proteína/metabolismo , Ratos , Ratos Sprague-Dawley , Triptofano/sangue , Tirosina/sangue
5.
Aesthet Surg J ; 28(2): 195-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19083527

RESUMO

The anatomic and physiological changes resulting from bariatric surgery can affect both nutrition and psychological attitudes. Modifications of the gastrointestinal tract lead to a diminished ability to absorb nutrients, electrolytes, and bile salts, as well as deficiencies in iron, calcium, and other vitamins and minerals. Dehydration, lactose intolerance, and protein calorie malnutrition are other common sequelae. Alterations in bone metabolism increase long-term risk for osteopenia and osteoporosis. Noncompliance with postsurgical nutritional regimens has been estimated to occur in from one third to almost two thirds of cases and can exacerbate these complications. Psychological issues are often present in patients with morbid obesity and can affect surgical outcomes. These issues include mood and personality disorders, destructive eating behaviors, and poor body image. Nearly one third of patients undergoing bariatric surgery also have a history of substance abuse disorder. The literature suggests that although the mental health of patients improves as a result of bariatric surgery, the benefits may be transient, and problems such as negative personality profiles, detrimental eating patterns, and negative body image persist to some extent. Identification of presurgical psychiatric problems can help identify those patients more likely to achieve lasting weight loss when surgery is combined with long-term follow-up to minimize medical and psychological complications.


Assuntos
Cirurgia Bariátrica/efeitos adversos , Obesidade Mórbida , Redução de Peso , Adaptação Psicológica , Cirurgia Bariátrica/psicologia , Imagem Corporal , Dieta Redutora , Humanos , Estilo de Vida , Fenômenos Fisiológicos da Nutrição , Obesidade Mórbida/dietoterapia , Obesidade Mórbida/psicologia
6.
Aesthet Surg J ; 28(3): 331-4, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19083545

RESUMO

In recent years, a growing number of severely obese adolescents and their families have sought out surgical treatment because behavioral or medical therapies were not successful. A number of reports have suggested that bariatric surgery for this patient group is safe and can provide durable weight loss. However, most of these reports have been retrospective studies with short-term outcomes, and more long-term, prospective studies are needed to optimize care for these patients. Evaluation of the severely obese patient for surgery involves multiple factors, including the overall maturity of the patient; joint discussions with the patient and his or her family; a complete medical evaluation; evaluation by a child psychologist or psychiatrist; and a minimum of 6 months of private, interdisciplinary, multifaceted lifestyle preparation. Surgical options are restricted to severely overweight adolescents without endocrine disorders who have achieved puberty and have failed more conservative therapies. The Roux-en-Y gastric bypass is the most commonly performed procedure in adolescents, but the laparoscopic adjustable gastric band procedure is growing in popularity. Postoperatively, patients are evaluated 2 weeks after surgery and then every 1 to 2 months for the first postoperative year; every 2 months to 6 months in the second year, depending on the individual case; and then annually for life. A careful diet plan backed by continuing family support is essential. Short- and long-term complications are similar to those seen in adults, and include bowel obstruction, bleeding, blood clots, nausea, gallstones, hernia, and vitamin and iron deficiencies.


Assuntos
Cirurgia Bariátrica , Obesidade/cirurgia , Cuidados Pré-Operatórios/métodos , Redução de Peso , Adolescente , Humanos , Obesidade/dietoterapia , Período Pós-Operatório , Fatores de Tempo , Estados Unidos
7.
Arch Surg ; 141(3): 276-83, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16549693

RESUMO

HYPOTHESIS: Systolic and diastolic pressure and the incidence of hypertension in very obese patients decline after bariatric surgery and do not rebound. DESIGN: Chart review. SETTING: Surgical practice in a university medical center. PATIENTS: Women and men, 18 years or older, with a body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) of 40 or greater, having no previous surgical intervention for extreme obesity. INTERVENTION: Vertical-banded gastroplasty or Roux-en-Y gastric bypass. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressure, BMI, and antihypertensive medications. RESULTS: Patients underwent Roux-en-Y gastric bypass (n = 285; mean initial BMI, 55.7) or vertical banded gastroplasty (n = 62; mean initial BMI, 48.5); half of each group was hypertensive at evaluation. The BMI dropped in both groups after surgery and stabilized at about 35 within 18 months. Systolic pressure changes were generally modest, although diastolic pressure declined significantly after surgery. In patients with untreated stage 1 hypertension, marked reductions in systolic and diastolic pressures occurred after surgery. Many patients taking antihypertensive medications before surgery discontinued them after surgery and remained normotensive. CONCLUSIONS: Blood pressure reductions that occur after bariatric surgery and substantial weight loss depend on the blood pressure status of patients before surgery: normotensive patients and hypertensive patients taking antihypertensive medications show small postsurgical pressure reductions, while patients with elevated blood pressure before surgery show notable postsurgical pressure drops. The overall incidence of hypertension after bariatric surgery declines substantially and remains low.


Assuntos
Pressão Sanguínea , Gastroplastia , Adulto , Fatores Etários , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Comorbidade , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/epidemiologia , Obesidade Mórbida/fisiopatologia , Obesidade Mórbida/cirurgia , Período Pós-Operatório , Estudos Retrospectivos
8.
J Clin Endocrinol Metab ; 89(3): 1061-5, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15001587

RESUMO

Little is known about the effects on the skeleton of laparoscopic Roux-en-Y gastric bypass (LRGB) surgery for morbid obesity and subsequent weight loss. We compared 25 patients who had undergone LRGB 11 +/- 3 months previously with 30 obese controls matched for age, gender, and menopausal status. Compared with obese controls, patients post LRGB had significantly lower weight (92 +/- 16 vs. 133 +/- 20 kg; P < 0.001) and body mass index (31 +/- 5 vs. 48 +/- 7 kg/m(2); P < 0.001). Markers of bone turnover were significantly elevated in patients post LRGB compared with controls (urinary N-telopeptide cross-linked collagen type 1, 93 +/- 38 vs. 24 +/- 11 nmol bone collagen equivalents per mmol creatinine; and osteocalcin, 11.6 +/- 3.4 vs. 7.6 +/- 3.6 ng/ml; both P < 0.001). Fifteen patients were studied prospectively for an average of 9 months after LRGB. They lost 37 +/- 9 kg and had a 29 +/- 8% fall in body mass index (both P < 0.001). Urinary N-telopeptide cross-linked collagen type 1 increased by 174 +/- 168% at 3 months (P < 0.01) and 319 +/- 187% at 9 months (P < 0.01). Bone mineral density decreased significantly at the total hip (7.8 +/- 4.8%; P < 0.001), trochanter (9.3 +/- 5.7%; P < 0.001), and total body (1.6 +/- 2.0%; P < 0.05), with significant decreases in bone mineral content at these sites. In summary, within 3 to 9 months after LRGB, morbidly obese patients have an increase in bone resorption associated with a decrease in bone mass. Additional studies are needed to examine these findings over the longer term.


Assuntos
Densidade Óssea , Remodelação Óssea , Derivação Gástrica/efeitos adversos , Obesidade Mórbida/cirurgia , Adulto , Osso e Ossos/metabolismo , Cálcio da Dieta/administração & dosagem , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Vitamina D/administração & dosagem , Redução de Peso
9.
Clin Nutr ; 32(6): 1073-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23395255

RESUMO

BACKGROUND & AIMS: The ingestion by rats of different proteins causes large differences in the plasma ratio of tryptophan to other large neutral amino acids, which predicts brain tryptophan uptake and serotonin synthesis. We evaluated in humans whether ingesting these proteins also produces large excursions in the tryptophan ratio. METHODS: Fasting males (n = 6) ingested V-8 Juice containing 40 g of α-lactalbumin, gluten, zein or starch. Blood was drawn before and at 30 min intervals after ingestion for 4 h; tryptophan and other large neutral amino acids were quantitated. RESULTS: Pre-meal plasma tryptophan was ~50 nmol/ml; the tryptophan ratio was ~0.010. α-Lactalbumin increased plasma tryptophan (3-fold) and the tryptophan ratio (50%); starch did not change either tryptophan variable, while gluten caused a modest (25%) and zein a large reduction (50%) in plasma tryptophan. Gluten and zein reduced the tryptophan ratio. The maximal difference in the tryptophan ratio occurred between α-lactalbumin and zein and was large (~3-fold). CONCLUSION: Since the plasma tryptophan ratio predicts brain tryptophan uptake and serotonin synthesis in rats, the differences in the ratio produced in humans by these proteins may modify serotonin synthesis, and perhaps elicit serotonin-linked changes in behavior.


Assuntos
Encéfalo/metabolismo , Proteínas Alimentares/administração & dosagem , Serotonina/biossíntese , Triptofano/sangue , Triptofano/farmacocinética , Adolescente , Adulto , Índice de Massa Corporal , Carboidratos da Dieta/administração & dosagem , Glutens/administração & dosagem , Humanos , Insulina/sangue , Lactalbumina/administração & dosagem , Masculino , Refeições , Adulto Jovem , Zeína/administração & dosagem
10.
Nutr Rev ; 70(5): 301-10, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22537216

RESUMO

Non-communicable diseases (NCDs), which include cardiovascular disease, cancer, and diabetes, all of which are associated with the common risk factors of poor diet and insufficient physical activity, caused 63% of all deaths globally in 2008. The increasing discussion of global NCDs, including at the 2011 United Nations General Assembly High-level Meeting on the Prevention and Control of Non-communicable Diseases, and a request for multi-stakeholder engagement, prompted the International Food Information Council Foundation to sponsor the Global Diet and Physical Activity Communications Summit: "Insights to Motivate Healthful, Active Lifestyles" on September 19, 2011, in New York City. The Summit brought together a diverse group of stakeholders, representing 34 nations from governments; communication, health, nutrition, and fitness professions; civil society; nonprofits; academia; and the private sector. The Summit provided expert insights and best practices for the use of science-based, behavior-focused communications to motivate individuals to achieve healthful, active lifestyles, with the goal of reducing the prevalence of NCDs. Presented here are some of the highlights and key findings from the Summit.


Assuntos
Doença Crônica/prevenção & controle , Comunicação , Dieta/normas , Exercício Físico/fisiologia , Saúde Global , Doença Crônica/epidemiologia , Congressos como Assunto , Humanos , Estilo de Vida , Prevalência
11.
Plast Reconstr Surg ; 126(2): 602-610, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20679842

RESUMO

BACKGROUND: Assessment of nutritional status in the growing postbariatric patient population remains controversial. Previous literature suggests that these patients have poor nutrition that may have adverse effects on surgical outcomes. The authors sought to determine the optimal method of nutritional assessment in postbariatric patients. METHODS: One hundred patients presenting for body contouring after bariatric surgery were consecutively enrolled in an institutional review board-approved prospective study. A trained nutritionist assessed protein and calorie intake. All patients underwent baseline laboratory assessment. RESULTS: Eighteen percent of subjects had less than the recommended daily protein intake. Hypoalbuminemia was observed in 13.8 percent of subjects, with hypoprealbuminemia in 6.5 percent. Nearly forty percent of all patients had evidence of iron deficiency, with vitamin B12 deficiency present in 14.5 percent. Ten percent of subjects (all women) were confirmed to have iron deficiency anemia. Impaired fasting glucose was seen in 6.2 percent of subjects, whereas 3.6 percent had hemoglobin A1c levels greater than 6.5. Increasing age (odds ratio, 1.07) and greater change in body mass index (odds ratio, 1.11) were predictors of low protein intake. Dumping syndrome led to 13.3 times increased odds of low albumin levels. CONCLUSIONS: The results suggest that inadequate nutrition is common among postbariatric patients presenting for body contouring. The lack of correlation between methods of nutritional assessment supports the combination of multiple methods in determining overall nutritional status. The presence of dumping syndrome, a large change in body mass index, and advanced age may help to identify patients with an increased risk of nutritional deficiency.


Assuntos
Cirurgia Bariátrica/efeitos adversos , Desnutrição/diagnóstico , Avaliação Nutricional , Obesidade Mórbida/cirurgia , Cirurgia Plástica/métodos , Adulto , Fatores Etários , Análise de Variância , Anemia/diagnóstico , Anemia/etiologia , Deficiência de Vitaminas/diagnóstico , Deficiência de Vitaminas/etiologia , Cirurgia Bariátrica/métodos , Índice de Massa Corporal , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Desnutrição/etiologia , Pessoa de Meia-Idade , Necessidades Nutricionais , Obesidade Mórbida/diagnóstico , Cuidados Pré-Operatórios/métodos , Probabilidade , Estudos Prospectivos , Medição de Risco , Fatores Sexuais , Resultado do Tratamento
12.
Physiol Behav ; 98(1-2): 156-62, 2009 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-19454292

RESUMO

Carbohydrate ingestion raises tryptophan uptake and serotonin synthesis in rat brain. The addition of protein is generally believed only to block such increases. However, some recent evidence suggests dietary protein may not be limited to this action. In the present studies, we fed rats single meals containing one of 5 proteins (zein, wheat gluten, soy protein isolate, casein, lactalbumin, 17% by weight) or no protein, and killed them 2.5 h later, 30 min after the injection of m-hydroxybenzylhydrazine, to allow serotonin and catecholamine synthesis rates to be measured in brain. Blood and cerebral cortex samples were analyzed for tryptophan and other large, neutral amino acids; 5-hydroxytryptophan and dihydroxyphenylalanine were measured in hypothalamus, hippocampus and cerebral cortex as indices of serotonin and catecholamine synthesis, respectively. An 8-fold variation occurred in cortex tryptophan: a marked decline followed zein ingestion, and modest reductions after casein or gluten. A large rise in cortex tryptophan occurred after lactalbumin consumption, and smaller increases after soy protein or carbohydrate (no protein). In the brain regions examined, a 4-8-fold range in serotonin synthesis occurred which closely followed the tryptophan alterations. No effects were observed in regional catecholamine synthesis rates. Cortical concentrations of leucine showed small changes; leucine has been linked to mTOR (mammalian target of rapamycin) signaling in brain circuits regulating food intake. The data suggest that tryptophan concentrations and serotonin synthesis in brain neurons are remarkably sensitive to which protein is present in a meal. Conceivably, this relationship might inform the brain about the nutritional quality of the protein ingested.


Assuntos
Aminoácidos/metabolismo , Química Encefálica/fisiologia , Catecolaminas/biossíntese , Proteínas Alimentares/farmacologia , Ingestão de Alimentos/fisiologia , Neurotransmissores/metabolismo , Serotonina/biossíntese , 5-Hidroxitriptofano/biossíntese , Animais , Química Encefálica/efeitos dos fármacos , Caseínas/farmacologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Dieta , Glutens/farmacologia , Cinética , Leucina/sangue , Leucina/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Proteínas de Soja/farmacologia , Triptofano/sangue , Triptofano/metabolismo , Tirosina/biossíntese , Tirosina/sangue
13.
Artigo em Inglês | MEDLINE | ID: mdl-19162795

RESUMO

Overweight and obesity have become an epidemic in many parts of the world threatening the health of over one billion people. In order to combat this epidemic effectively, it is desirable to develop new methods to monitor individual's food intake and provide quantitative information about the nutrients and calories consumed in people's daily life. We present an electronic photographic approach and associated image processing algorithms to estimate food portion size, which is then utilized to obtain the required information. Our experiments show that our approach is accurate, providing an effective tool for people to track their nutritional and energy intake.


Assuntos
Dieta , Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Análise de Alimentos/métodos , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Fotografação/métodos , Algoritmos , Inteligência Artificial , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
J Nutr ; 137(6 Suppl 1): 1539S-1547S; discussion 1548S, 2007 06.
Artigo em Inglês | MEDLINE | ID: mdl-17513421

RESUMO

Aromatic amino acids in the brain function as precursors for the monoamine neurotransmitters serotonin (substrate tryptophan) and the catecholamines [dopamine, norepinephrine, epinephrine; substrate tyrosine (Tyr)]. Unlike almost all other neurotransmitter biosynthetic pathways, the rates of synthesis of serotonin and catecholamines in the brain are sensitive to local substrate concentrations, particularly in the ranges normally found in vivo. As a consequence, physiologic factors that influence brain pools of these amino acids, notably diet, influence their rates of conversion to neurotransmitter products, with functional consequences. This review focuses on Tyr and phenylalanine (Phe). Elevating brain Tyr concentrations stimulates catecholamine production, an effect exclusive to actively firing neurons. Increasing the amount of protein ingested, acutely (single meal) or chronically (intake over several days), raises brain Tyr concentrations and stimulates catecholamine synthesis. Phe, like Tyr, is a substrate for Tyr hydroxylase, the enzyme catalyzing the rate-limiting step in catecholamine synthesis. Tyr is the preferred substrate; consequently, unless Tyr concentrations are abnormally low, variations in Phe concentration do not affect catecholamine synthesis. Unlike Tyr, Phe does not demonstrate substrate inhibition. Hence, high concentrations of Phe do not inhibit catecholamine synthesis and probably are not responsible for the low production of catecholamines in subjects with phenylketonuria. Whereas neuronal catecholamine release varies directly with Tyr-induced changes in catecholamine synthesis, and brain functions linked pharmacologically to catecholamine neurons are predictably altered, the physiologic functions that utilize the link between Tyr supply and catecholamine synthesis/release are presently unknown. An attractive candidate is the passive monitoring of protein intake to influence protein-seeking behavior.


Assuntos
Encéfalo/metabolismo , Catecolaminas/biossíntese , Fenilalanina/biossíntese , Tirosina/biossíntese , Animais , Di-Hidroxifenilalanina/biossíntese , Hidroxilação , Cinética , Ratos , Retina/metabolismo
15.
Ann Plast Surg ; 58(1): 54-6, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17197942

RESUMO

Postbariatric body contouring is an expanding and rapidly evolving specialty within plastic surgery. To best address the many clinical issues related to the safe and effective care of the postbariatric patient, the authors have established a dedicated multidisciplinary treatment center. Team building efforts have brought together attending plastic surgeons who specialize in body contouring, nurses focused on body contouring after weight loss, and an administrative staff well trained in the issues related to managing these specific types of cases. Through core partnerships, nutritionists, lifestyle counselors, and psychologic professionals are present in the clinic to evaluate patients alongside the plastic surgeon. A dedicated physician assistant and body-contouring fellow work in both the clinic and the operating room (OR). This team approach has allowed for the establishment of defined screening procedures and patient care algorithms. Outreach and patient education initiatives have allowed the center to forge strong alliances with the regional bariatric surgeons and make patients aware of the role of plastic surgery as they start the process of weight loss. A strong research mission is demonstrated by an IRB-approved clinical registry and database that facilitate outcomes studies.


Assuntos
Cirurgia Bariátrica , Continuidade da Assistência ao Paciente/organização & administração , Obesidade Mórbida/cirurgia , Algoritmos , Humanos
16.
Obesity (Silver Spring) ; 15(6): 1464-72, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17557984

RESUMO

OBJECTIVE: Our objective was to assess the efficacy and safety of sibutramine with a low-calorie diet (LCD) and commercial meal-replacement product in achieving weight loss and weight-loss maintenance in obese patients. RESEARCH METHODS AND PROCEDURES: Eight U.S. centers recruited 148 obese patients for a 3-month comprehensive weight-loss therapy (Phase I) comprising daily sibutramine 10 mg + LCD (two Slim-Fast meal-replacement shakes, one low-calorie meal; total kcal/d = 1200-1500). Patients (N = 113) who lost > or =5% of initial body weight during Phase I were randomized for a 9-month period (Phase II) to daily sibutramine 15 mg + LCD (one meal-replacement shake; two low-calorie meals: total kcal/d approximately 1200-1500) or daily placebo + three low-calorie meals (total kcal/d approximately 1200-1500). Both phases included behavior modification. Efficacy was assessed by body weight change during each phase and by the number of patients at endpoint maintaining > or =80% of the weight they had lost by the end of Phase I. Other outcomes included changes in cardiovascular and metabolic risk factors, adverse events, and vital signs. RESULTS: Mean body weight change during Phase I was -8.3 kg (p < 0.001). Patients randomized to sibutramine in Phase II had an additional -2.5 kg mean weight loss vs. a 2.8-kg increase in the placebo group (p < 0.001). More sibutramine patients maintained > or =80% of their Phase I weight loss at the end of Phase II (85.5% vs. placebo 36.7%, p < 0.001). Most adverse events were mild or moderate in severity, and all serious adverse events were unrelated to sibutramine. DISCUSSION: Sibutramine plus LCD with meal replacements and behavior modification is a safe and effective strategy for achieving and sustaining weight loss in obese patients.


Assuntos
Depressores do Apetite/uso terapêutico , Ciclobutanos/uso terapêutico , Dieta Redutora , Alimentos Formulados , Obesidade/dietoterapia , Obesidade/tratamento farmacológico , Obesidade/prevenção & controle , Redução de Peso , Adolescente , Adulto , Algoritmos , Depressores do Apetite/efeitos adversos , Terapia Comportamental , Terapia Combinada/efeitos adversos , Ciclobutanos/efeitos adversos , Humanos , Pessoa de Meia-Idade , Obesidade/metabolismo , Placebos , Método Simples-Cego , Redução de Peso/efeitos dos fármacos
17.
J Nutr ; 136(2): 553S-559S, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16424146

RESUMO

Brain tryptophan (TRP) concentrations and serotonin (5HT) synthesis and release increase during running. This increase in 5HT function may promote central fatigue and contribute to suboptimal physical performance. The rise in brain TRP is reputed to result from exercise-induced elevations in serum nonesterified fatty acid (NEFA) concentrations, which dissociate TRP from albumin in blood and increase the serum free TRP pool. But, as discussed in this article, ample evidence exists that the serum free TRP pool does not control brain TRP uptake. The clearest data are dietary, but pharmacologic data in exercising rats also support this conclusion. Changes in the serum levels of amino acids that compete with TRP for brain uptake appear also not to explain the rise in brain TRP. The mechanism is therefore not presently known. The link between the rise in brain TRP and 5HT synthesis/release is not simple: a rise in brain TRP stimulates 5HT synthesis/release in actively firing neurons. Hence, during exercise, only 5HT neurons that are firing should increase 5HT production/release when brain TRP rises. It is not known which 5HT neurons fire during exercise; the 5HT neurons that respond to exercise-induced increases in brain TRP are therefore not known. Hence, it is not possible to conclude which 5HT neurons contribute to the generation of central fatigue. Because some 5HT neurons control specific functions important to physical performance (e.g., respiration), the current understanding of 5HT neuronal function in central fatigue might benefit from the study of specific 5HT pathways during exercise.


Assuntos
Fadiga/sangue , Condicionamento Físico Animal/fisiologia , Triptofano/sangue , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Fadiga/tratamento farmacológico , Ácidos Graxos não Esterificados/sangue , Neurônios/metabolismo , Niacina/farmacologia , Ratos , Serotonina/biossíntese , Serotonina/metabolismo , Triptofano/metabolismo
18.
Plast Reconstr Surg ; 117(1): 15-24, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16404242

RESUMO

BACKGROUND: Characterization of optimal aesthetics in transverse rectus abdominis musculocutaneous (TRAM) breast reconstruction is a challenge that even the most experienced breast surgeon faces. Aesthetic assessment in breast surgery has attempted to evaluate the reconstructed breast either as one cohesive entity or as a sum of its parts. The authors propose that the most advantageous assessment involves looking at the reconstructions in terms of aesthetic components, not necessarily in visual subunits. METHODS: The authors investigated the responses of five physicians and 12 nonphysician evaluators using various methods of aesthetic assessment, including, most importantly, a visual analogue scale survey. Pearson's correlation and intraclass correlation analyses were performed using SAS software. RESULTS: Their analysis determined that while all components of TRAM reconstruction were important, symmetry, contour, and breast positioning were consistently named the most important components of breast reconstruction. When the breast reconstruction was divided into aesthetic subunits, there was a high degree of correlation between the overall score and the subunit scores (r = 0.81: r > 0.6 for good correlation). CONCLUSIONS: From these assessments, the authors derived a set of aesthetic rules for TRAM flap reconstruction. They believe that methodical application of these rules on a consistent basis can lead to the production of maximal aesthetic outcomes in TRAM breast reconstruction.


Assuntos
Mamoplastia , Retalhos Cirúrgicos , Estética , Humanos , Resultado do Tratamento
19.
Obesity (Silver Spring) ; 14(9): 1626-36, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17030974

RESUMO

OBJECTIVE: Because post-bariatric surgery patients undergo massive weight loss, the resulting skin excess can lead to both functional problems and profound dissatisfaction with appearance. Correcting skin excess could improve all these corollaries, including body image. Presently, few data are available documenting body image and weight-related quality of life in this population. RESEARCH METHODS AND PROCEDURES: Eighteen patients who underwent both bariatric surgery and body contouring completed our study. Both established surveys and new surveys designed specifically for the study were used to assess body perception and ideals, quality of life, and mood. Patients were surveyed at the following time-points: pre-body contouring (after massive weight loss) and both 3 and 6 month post-body contouring. Statistical testing was performed using Student's t test and ANOVA. RESULTS: The mean age of the patients was 46 +/- 10 years (standard deviation). Quality of life improved after obesity surgery and was significantly enhanced after body contouring. Three months after body contouring, subjects ascribed thinner silhouettes to both current appearance and ideal body image. Body image also improved with body contouring surgery. Mood remained stable over 6 months. DISCUSSION: Body contouring after surgical weight loss improved both quality-of-life measurements and body image. Initial body dissatisfaction did not correlate with mood. Body contouring improved body image but produced dissatisfaction with other parts of the body, suggesting that as patients become closer to their ideal, these ideals may shift. We further developed several new assessment methods that may prove useful in understanding these post-surgical weight loss patients.


Assuntos
Cirurgia Bariátrica/métodos , Procedimentos Cirúrgicos Dermatológicos , Obesidade Mórbida/psicologia , Obesidade Mórbida/cirurgia , Redução de Peso , Análise de Variância , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/psicologia , Imagem Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Satisfação do Paciente , Qualidade de Vida , Autoimagem , Estatísticas não Paramétricas , Fatores de Tempo , Redução de Peso/fisiologia
20.
Plast Reconstr Surg ; 116(5): 1535-44; discussion 1545-6, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16217505

RESUMO

BACKGROUND: Contour deformities after massive weight loss are diverse and often severe in nature. Current progress has necessitated a valid, accessible, and comprehensive rating system that correlates appearance and appropriate surgical treatment. Presently, no existing rating system addresses the breadth and variety of deformities that can occur or allows for adequate postsurgical evaluation. METHODS: The authors reviewed full-body photographs of over 300 female patients seen between October of 2002 and May of 2004. The authors targeted body areas most frequently demonstrating skin and soft-tissue laxity and ptosis. A 10-region, four-point grading system was designed to describe the common deformities found in each region of the body. To validate the scale, 12 trained observers applied the rating scale to photographs of 25 patients who showed the 10 regions. Each grading scale ranged from 0, indicating normal, to 3, indicating the most severe deformity. Repeat testing was performed at 2 weeks. Interobserver validity and test-retest reliability were determined using weighted kappa analysis. RESULTS: In all 10 categories, the kappa value was 0.6 or higher (0.6 = threshold for good validity), with a mean kappa value of 0.68 (range, 0.61 to 0.78) and an overall agreement of 69 percent over two sessions. All 12 observers scored an individual mean kappa value of greater than 0.6, indicating good interobserver validity. A given observer had a mean 67 percent agreement, indicating reasonable test-retest reliability. CONCLUSIONS: The Pittsburgh Rating Scale is a validated measure of contour deformities after bariatric weight loss. This scale may have applications in preoperative planning and evaluating surgical outcomes.


Assuntos
Tecido Adiposo/cirurgia , Procedimentos Cirúrgicos Dermatológicos , Derivação Gástrica , Abdome/cirurgia , Estética , Feminino , Humanos , Obesidade Mórbida/cirurgia , Variações Dependentes do Observador , Período Pós-Operatório , Reprodutibilidade dos Testes , Redução de Peso
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