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OBJECTIVES: To investigate the histologic characteristics of vulvar tissues before and after completion of fractionated carbon dioxide (CO2 ) laser therapy (FxCO2) for vulvar lichen sclerosus (LS). The secondary objective was to assess subjective improvement in symptoms via the Skindex-16 questionnaire. METHODS: This prospective single-arm study was conducted from April 2021 to August 2022 at one academic medical center. Ten postmenopausal women with biopsy-proven LS planning FxCO2 laser treatment were enrolled. Exclusion criteria included prior transvaginal mesh for prolapse, topical corticosteroid use within 8 weeks, prior pelvic radiation, malignancy, active genital infection, or pregnancy. The vulvovaginal SmartXide2-V2-LR laser system fractionated CO2 laser (DEKA) was utilized to treat visually affected areas of vulvar and perianal LS with a single pass. Subjects underwent three treatments 4-6 weeks apart. Subjects completed the Skindex-16 questionnaire and had vulvar biopsy at baseline and at 4 weeks after completion of fractionated CO2 laser therapy. Blinded histologic slides were scored by one dermatopathologist (Michael A. Cardis) rating from 1 to 5 the degree of dermal sclerosis, inflammation, and epidermal atrophy. Change scores were calculated as the difference between pre- and post-treatment scores for each subject. RESULTS: The 10 subjects enrolled had a mean age of 61 and most were white, privately insured, and had a college/graduate-level education. Post-fractionated CO2 laser treatment vulvar biopsies showed significant improvement in sclerosis and epidermal atrophy compared with pretreatment baseline biopsy specimens (p < 0.05) with no statistically significant change found in inflammation score. Skindex-16 and FSFI scores showed a trend towards improvement (p > 0.05 for both). A statistically significant correlation was found between change in sclerosis and Skindex-16 symptoms scores with an average change of 21.4 units in Skindex-16 symptoms score for every one-point change in histologic sclerosis score (p = 0.03). CONCLUSIONS: In postmenopausal women with vulvar LS undergoing fractionated CO2 laser, symptomatic improvements correlated with histologic change in degree of sclerosis on vulvar biopsy. These results demonstrate FxCO2 laser therapy as a promising option for the treatment of LS and suggest that further studies should assess degree of sclerosis on histopathology.
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Liquen Escleroso y Atrófico , Liquen Escleroso Vulvar , Humanos , Femenino , Persona de Mediana Edad , Liquen Escleroso y Atrófico/complicaciones , Liquen Escleroso y Atrófico/patología , Dióxido de Carbono , Proyectos Piloto , Posmenopausia , Esclerosis/complicaciones , Estudios Prospectivos , Liquen Escleroso Vulvar/complicaciones , Liquen Escleroso Vulvar/patología , Liquen Escleroso Vulvar/terapia , Inflamación , Biopsia , Atrofia/complicacionesRESUMEN
Treatment outcomes associated with the use of novel COVID-19 therapeutics in solid organ transplant recipients (SOTR) are not well described in the literature. The objective of this analysis was to characterize 30-day hospitalization and other key secondary endpoints experienced by outpatient SOTR with mild-moderate COVID-19 treated with nirmatrelvir/ritonavir (NR), sotrovimab, or no SARS-CoV-2 specific treatment. This IRB-approved, retrospective study included 154 SOTR with a documented positive SARS-CoV-2 infection between December 16, 2021 and January 19, 2022 (a predominant Omicron BA.1 period in New York City). Patients who received NR (N = 28) or sotrovimab (N = 51) experienced a lower rate of 30-day hospitalization or death as compared to those who received no specific treatment (N = 75) (p = .009). A total of three deaths occurred, all among patients who initially received no specific treatment prior to hospitalization. These results suggest a role for SARS-CoV-2 specific agents in the treatment of SOTR with COVID-19, and that there does not appear to be any difference in effectiveness when comparing NR versus sotrovimab.
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COVID-19 , Trasplante de Órganos , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Estudios Retrospectivos , Trasplante de Órganos/efectos adversos , Receptores de TrasplantesRESUMEN
There are no guidelines for antibiotic prophylaxis for ureteral stent removal after kidney transplantation. We reviewed the charts of 277 adult kidney transplant recipients with ureteral stents transplanted at our center between September 2014 and December 2015 and investigated whether antibiotic prophylaxis for stent removal was associated with reduced incidence of urinary tract infections (UTI). We defined UTI as a urine culture ≥104 CFU/mL of bacterial isolates irrespective of symptoms. Primary outcome was the incidence of UTI within four weeks of stent removal. Among the 277 recipients, 199 (72%) were on sulfamethoxazole/trimethoprim (SMZ/TMP) as Pneumocystis jirovecii prophylaxis. At the time of ureteral stent removal, 56 recipients (20%) received additional antibiotic prophylaxis (ABX+) and 221 (80%) did not (ABX-). The difference in the incidence of UTI in the ABX(+) group (16%) and ABX(-) group (19%) was not statistically significant (P = 0.85). Variables independently associated with the development of UTI were recipient age (odds ratio [OR] 1.04, [95% confidence interval 1.01-1.07]) and UTI while stents were in situ (OR 3.9 [2.00-7.62]). Use of SMZ/TMP was protective (OR 0.35 [0.18-0.7]). Our study does not show a statistically significant benefit for additional antibiotic prophylaxis for ureteral stent removal. Antibiotic prophylaxis may be beneficial for recipients not on SMZ/TMP at the time of stent removal.
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Profilaxis Antibiótica/métodos , Remoción de Dispositivos/efectos adversos , Rechazo de Injerto/epidemiología , Fallo Renal Crónico/cirugía , Trasplante de Riñón/mortalidad , Stents/efectos adversos , Infecciones Urinarias/epidemiología , Femenino , Estudios de Seguimiento , Rechazo de Injerto/tratamiento farmacológico , Rechazo de Injerto/etiología , Supervivencia de Injerto , Humanos , Incidencia , Masculino , Persona de Mediana Edad , New York/epidemiología , Complicaciones Posoperatorias , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Uréter/cirugía , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/etiologíaRESUMEN
Surgical stress, corticosteroids, and mycophenolate may contribute to gastrointestinal ulcers/bleeding after kidney transplantation. Prophylactic acid suppression with H2RAs or PPIs is often utilized after transplantation, although unclear if truly indicated after early corticosteroid withdrawal (CSWD). PPIs have been associated with increased risks of Clostridium difficile infection (CDI), pneumonia, and acute rejection. This retrospective cohort study investigated benefits and risks of prolonged PPI use following kidney transplantation and included 286 kidney recipients undergoing CSWD within five d of transplant who were maintained on tacrolimus and mycophenolate mofetil/sodium. Patients on PPI before transplant, H2RA before/after transplant, and/or those with pre-transplant GI complications were excluded. A total of 171 patients received PPI>30 d, mean duration 287 ± 120 d (PPI group); 115 patients were not maintained on acid suppression (No-PPI group). GI ulceration and bleeding events were rare in PPI group (1.2% and 2.3%, respectively) and not observed in No-PPI group (p = NS). The incidence of infectious or hematological complications was not significantly different between groups. The PPI group experienced more biopsy-proven acute rejection (9.4% vs. 2.6%, p = 0.03). No direct benefit was observed with PPI in reducing the incidence of GI ulcers and bleeding events in kidney transplant recipients undergoing early CSWD. Further studies are needed to investigate the association of PPI and acute rejection.
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Corticoesteroides/administración & dosificación , Rechazo de Injerto/tratamiento farmacológico , Inmunosupresores/administración & dosificación , Trasplante de Riñón/efectos adversos , Complicaciones Posoperatorias , Inhibidores de la Bomba de Protones/uso terapéutico , Privación de Tratamiento , Adolescente , Adulto , Femenino , Rechazo de Injerto/etiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Receptores de Trasplantes , Adulto JovenRESUMEN
Oceanographic lidar profiles measured in an aerial survey were compared with in situ measurements of water optical properties made from a surface vessel. Experimental data were collected over a two-week period in May 2010 in East Sound, Washington. Measured absorption and backscatter coefficients were used with the volume-scattering function in a quasi-single-scattering model to simulate an idealized lidar return, and this was convolved with the measured instrument response to accurately reproduce the measured temporal behavior. Linear depth-dependent depolarization from the water column and localized depolarization from scattering layers are varied to fine tune the simulated lidar return. Sixty in situ measurements of optical properties were correlated with nearly collocated and coincident lidar profiles; our model yielded good matches (±3 dB to a depth of 12 m) between simulated and measured lidar profiles for both uniform and stratified waters. Measured attenuation was slightly higher (5%) than diffuse attenuation for the copolarized channel and slightly lower (8%) for the cross-polarized channel.
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OBJECTIVE: To assess international shortfall inequality in life expectancy at birth among women and men and the influence of geography and country income group. METHODS: The authors used estimates of life expectancy at birth, by sex, for 12 five-year periods between 1950-1955 and 2005-2010 and estimates of population for the midpoints of each period from the World population prospects, 2008 revision. Shortfall inequality was defined as the weighted average of the deviations of each country's average life expectancy by sex from the highest attained life expectancy by sex for each period. FINDINGS: International shortfall inequalities in life expectancy among men and among women decreased between 1950 and 1975 but stagnated thereafter. International shortfall inequality in life expectancy has been higher in women than in men, ranging from 1.9 to 2.9 years. Women in low-income countries have the biggest shortfall, currently at around 26.7 years. CONCLUSION: International shortfall inequality is higher among women than men primarily because women in low-income and lower-middle-income country groups show larger differences in life expectancy than men. Further investigation is needed to determine the pathways causing these inequalities.
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Países Desarrollados/estadística & datos numéricos , Países en Desarrollo/estadística & datos numéricos , Salud Global/estadística & datos numéricos , Esperanza de Vida/tendencias , Femenino , Humanos , Masculino , Distribución por Sexo , Clase SocialRESUMEN
PURPOSE: To investigate MRI biomarkers of muscle atrophy during cast immobilization of the lower leg. MATERIALS AND METHODS: Eighteen patients (8 male, 10 female), who had one lower leg immobilized in a cast, underwent 3.0 Tesla (T) MR imaging 5, 8, 15, 29, and 43 days after casting. Measurements were made on both lower legs of total muscle volume. Cross-sectional area (CSA), fractional water content, and T(2) were measured in tibialis anterior (TA), gastrocnemius medialis (GM) and lateralis (GL) and soleus (SOL). Fiber pennation angle was measured in GM. RESULTS: Total muscle volume decreased by 17% (P < 0.001) over the 6 weeks of immobilization. The greatest loss in CSA (mean[SD]) was seen in GM (-23.3(8.7)%), followed by SOL (-19.0(9.8)%), GL (-17.1(6.5)%), and TA (-10.7(5.9)%). Significant reductions of CSA were also detectable in the contra-lateral leg. T(2) increased in all muscles: TA 27.0(2.5) ms to 29.6(2.8) ms (P < 0.001), GM 34.6(2.9) ms to 39.8(5.4) ms (P < 0.001) and SOL 34.4 (2.9) ms to 44.9(5.9) ms (P < 0.001). Small reductions were found in fractional water content. Pennation angle decreased in the cast leg (P < 0.001). CONCLUSION: Quantitative MR imaging can detect and monitor progressive biochemical and biophysical changes in muscle during immobilization.
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Traumatismos del Tobillo/patología , Traumatismos del Tobillo/terapia , Fracturas Óseas/patología , Pierna/patología , Imagen por Resonancia Magnética/métodos , Atrofia Muscular/patología , Adulto , Anciano , Análisis de Varianza , Moldes Quirúrgicos , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Estudios Longitudinales , Masculino , Persona de Mediana EdadRESUMEN
We demonstrate generation of Cerenkov radiation at 850 nm in a higher-order-mode (HOM) fiber. The LP02 mode in this solid, silica-based fiber has anomalous dispersion from 690 nm to 810 nm. Cerenkov radiation with 3 nJ pulse energy is generated in this module, exhibiting 60% energy conversion efficiency from the input. The HOM fiber provides a valuable fiber platform for nonlinear wavelength conversion with pulse energies in-between index-guided silica-core photonic crystal fibers and air-core photonic bandgap fibers.
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Fibras Ópticas , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Dispersión de RadiaciónRESUMEN
Pro-inflammatory cytokines induce meniscal matrix degradation and inhibition of endogenous repair mechanisms, but the pathogenic mechanisms behind this are mostly unknown. Therefore, we investigated details of interleukin-1 (IL-1alpha)-induced aggrecan turnover in mature meniscal tissue explants. Fibro-cartilagenous disks (3 mm diameter x 1 mm thickness) were isolated from the central, weight-bearing region of menisci from 2-year-old cattle. After 3 or 6 days of IL-1alpha-treatment, GAG loss (DMMB assay), biosynthetic activity ([(35)SO(4)]-sulfate and [(3)H]-proline incorporation), gene expression (quantitative RT-PCR) and the abundance (zymography, Western blot) of matrix-degrading enzymes and specific aggrecan products were determined. Meniscal fibrocartilage had a 4-fold lower GAG content (per wet weight) than adjacent articular cartilage, and expressed MMPs-1, -2, -3 and ADAMTS4 constitutively, whereas ADAMTS5 m-RNA was essentially undetectable. Significant IL-1 effects were a decrease in biosynthetic activity, an increase in GAG release and in the expression/abundance of MMP-2, MMP-3 and ADAMTS4. Fresh tissue contained aggrecan core protein products similar to those previously described for bovine articular cartilage of this age. IL-1 induced the release of aggrecanase-generated CS-substituted products including both high (>250 kDa) and low molecular weight (about 75 kDa) species. TIMP-3 (but not TIMP-1 and -2 or a broad spectrum MMP inhibitor) inhibited IL-1-dependent GAG loss. In addition, IL-1 induced the release of preformed pools of three known G1-bearing products. We conclude that aggrecanases are responsible for IL-1-stimulated GAG release from meniscal explants, and that IL-1 also stimulates release of G1-bearing products, by a process possibly involving hyaluronan fragmentation.
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Agrecanos/metabolismo , Artritis/inmunología , Glicosaminoglicanos/metabolismo , Mediadores de Inflamación/metabolismo , Interleucina-1alfa/metabolismo , Meniscos Tibiales/inmunología , Proteínas ADAM/efectos de los fármacos , Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Proteína ADAMTS4 , Agrecanos/efectos de los fármacos , Animales , Artritis/metabolismo , Artritis/fisiopatología , Calpaína/efectos de los fármacos , Calpaína/genética , Calpaína/metabolismo , Bovinos , Endopeptidasas/efectos de los fármacos , Endopeptidasas/genética , Endopeptidasas/metabolismo , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Ácido Hialurónico/metabolismo , Mediadores de Inflamación/farmacología , Interleucina-1alfa/farmacología , Metaloproteinasas de la Matriz/efectos de los fármacos , Metaloproteinasas de la Matriz/genética , Metaloproteinasas de la Matriz/metabolismo , Meniscos Tibiales/efectos de los fármacos , Meniscos Tibiales/metabolismo , Modelos Biológicos , Procolágeno N-Endopeptidasa/efectos de los fármacos , Procolágeno N-Endopeptidasa/genética , Procolágeno N-Endopeptidasa/metabolismo , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Inhibidor Tisular de Metaloproteinasa-3/efectos de los fármacos , Inhibidor Tisular de Metaloproteinasa-3/genética , Inhibidor Tisular de Metaloproteinasa-3/metabolismoRESUMEN
We use the time-lens concept to demonstrate a new scheme for synchronization of two pulsed light sources for biological imaging. An all fiber, 1064 nm time-lens source is synchronized to a picosecond solid-state Ti: Sapphire mode-locked laser by using the mode-locked laser pulses as the clock. We demonstrate the application of this synchronized source for CARS and SRS imaging by imaging mouse tissues. Synchronized two wavelength pulsed source is an important technical difficulty for CARS and SRS imaging. The time-lens source demonstrated here may provide an all fiber, user friendly alternative for future SRS imaging.
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Excitation-inhibition (E-I) imbalance is considered a hallmark of various neurodevelopmental disorders, including schizophrenia and autism. How genetic risk factors disrupt coordinated glutamatergic and GABAergic synapse formation to cause an E-I imbalance is not well understood. Here, we show that knockdown of Disrupted-in-schizophrenia 1 (DISC1), a risk gene for major mental disorders, leads to E-I imbalance in mature dentate granule neurons. We found that excessive GABAergic inputs from parvalbumin-, but not somatostatin-, expressing interneurons enhance the formation of both glutamatergic and GABAergic synapses in immature mutant neurons. Following the switch in GABAergic signaling polarity from depolarizing to hyperpolarizing during neuronal maturation, heightened inhibition from excessive parvalbumin+ GABAergic inputs causes loss of excitatory glutamatergic synapses in mature mutant neurons, resulting in an E-I imbalance. Our findings provide insights into the developmental role of depolarizing GABA in establishing E-I balance and how it can be influenced by genetic risk factors for mental disorders.
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Predisposición Genética a la Enfermedad , Trastornos Mentales/genética , Neuronas/fisiología , Sinapsis/fisiología , Ácido gamma-Aminobutírico/fisiología , Animales , Polaridad Celular , Femenino , Neuronas GABAérgicas/fisiología , Técnicas de Silenciamiento del Gen , Masculino , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/fisiología , Inhibición Neural , Neurogénesis/genética , Neurogénesis/fisiología , Factores de Riesgo , Sinapsis/genética , Potenciales SinápticosRESUMEN
Soliton self-frequency shift (SSFS), a consequence of Raman self-pumping that continuously red-shifts a soliton pulse, has been widely studied recently for applications to fiber-based sources and signal processing. In this paper, the fundamentals of SSFS are reviewed. Various fiber platforms for SSFS (single-mode fiber, microstructured fiber, and higher order mode fiber) are presented and experimental SSFS demonstrations in these fibers are discussed. Observation of Cerenkov radiation in fibers exhibiting SSFS is also presented. A number of interesting applications of SSFS, such as wavelength-agile lasers, analog-to-digital conversion, and slow light, are briefly discussed.
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CONTEXT: Highly active antiretroviral therapy (HAART) for HIV-1 infection has been associated with a metabolic syndrome characterized by insulin resistance, hyperlipidemia, and redistribution of body fat (lipodystrophy). A subset of patients with predominant lipoatrophy has low levels of the adipocyte-secreted hormone leptin. OBJECTIVE: The objective of the study was to assess whether administration of recombinant methionyl human leptin (r-metHuLeptin) improves insulin resistance and other metabolic abnormalities in HIV+ leptin-deficient subjects with HAART-induced lipoatrophy. DESIGN, SETTING, PATIENTS, AND INTERVENTION: We conducted a randomized, placebo-controlled, double-blinded, crossover study from 2002 to 2004 in seven HIV+ men with HAART-induced lipoatrophy, serum leptin level less than 3 ng/ml, and fasting triglyceride level greater than 300 mg/dl, who were administered placebo for 2 months before or after administration of r-metHuLeptin at physiological doses for an additional 2 months. MAIN OUTCOME MEASURES: Insulin resistance, lipid levels, inflammatory markers, body composition, and HIV control were measured. RESULTS: Compared with placebo, r-metHuLeptin therapy improved fasting insulin levels, insulin resistance (as expressed by the homeostasis model assessment index and an insulin suppression test), and high-density lipoprotein. Body weight and fat mass decreased on r-metHuLeptin, mainly due to a decrease in truncal fat but not peripheral fat or lean body mass. r-metHuLeptin was well tolerated, and HIV control was not adversely affected. CONCLUSIONS: r-metHuLeptin replacement at physiological doses in HIV+ leptin-deficient patients with HAART-induced lipoatrophy improves insulin resistance, high-density lipoprotein, and truncal fat mass. Future larger and more long-term studies in HAART-induced lipoatrophy, including patients with more severe metabolic abnormalities, are warranted to evaluate the physiological and potentially therapeutic role of r-metHuLeptin for this condition and to fully clarify the underlying mechanisms of action.
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Terapia Antirretroviral Altamente Activa/efectos adversos , Síndrome de Lipodistrofia Asociada a VIH/inducido químicamente , Resistencia a la Insulina , Leptina/análogos & derivados , Leptina/deficiencia , Síndrome Metabólico/inducido químicamente , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Adolescente , Adulto , Composición Corporal , Índice de Masa Corporal , Estudios Cruzados , Método Doble Ciego , VIH-1 , Síndrome de Lipodistrofia Asociada a VIH/metabolismo , Humanos , Insulina/sangre , Interleucina-6/sangre , Leptina/uso terapéutico , Lípidos/sangre , Lipoproteínas HDL/sangre , Masculino , Síndrome Metabólico/metabolismo , Placebos , Proteínas Recombinantes/uso terapéuticoRESUMEN
CONTEXT: Adiponectin, an adipocyte-secreted hormone, is associated with insulin resistance and the metabolic syndrome. OBJECTIVE: The physiological regulation of circulating adiponectin levels and mRNA expression of its receptors (AdipoR1 and AdipoR2) in skeletal muscle remains to be fully elucidated. DESIGN/PATIENTS: We assessed circulating adiponectin and AdipoR1/R2 mRNA expression in human skeletal muscle in a cross-sectional study of 140 subjects with normal or impaired glucose tolerance or type 2 diabetes. In the context of an interventional study, the same measurements were performed in 60 of these subjects (20/glucose tolerance group) before and after 4 wk of physical training. Finally, we measured these same variables in addition to protein levels of AMP kinase (AMPK), acetyl phosphorylated AMPK, coenzyme A carboxylase, phosphorylated coenzyme A carboxylase, and phosphatidylinositol 3-kinase in muscle before and after 3 h of intensive exercise in a subgroup of five subjects. SETTING: This study was performed at an academic clinical research center. RESULTS: Circulating adiponectin was negatively associated, whereas AdipoR1/R2 mRNA levels were positively associated with obesity, glucose and lipid levels, and insulin resistance. Physical training for 4 wk resulted in increased circulating adiponectin levels and AdipoR1/R2 mRNA expression in muscle. Exercise for 3 h increased AdipoR1/R2 mRNA expression as well as phosphorylation of AMPK and acetyl coenzyme A carboxylase in muscle, but had no effect on circulating adiponectin. CONCLUSIONS: Adiponectin, AdipoR1, and AdipoR2 are all associated with body composition, insulin sensitivity, and metabolic parameters. Physical training increases circulating adiponectin and mRNA expression of its receptors in muscle, which may mediate the improvement of insulin resistance and the metabolic syndrome in response to exercise.
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Adiponectina/sangre , Ejercicio Físico , Resistencia a la Insulina , Músculo Esquelético/metabolismo , Receptores de Superficie Celular/genética , Adulto , Índice de Masa Corporal , Estudios Transversales , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Leptina/sangre , Lípidos/sangre , Masculino , Persona de Mediana Edad , Receptores de AdiponectinaRESUMEN
Leptin is an adipocyte-secreted hormone that regulates energy homeostasis and neuroendocrine function. Replacement therapy with recombinant methionyl human leptin (r-metHuLeptin) improves obesity, insulin resistance, hyperlipidemia, and neuroendocrine dysfunction associated with low-leptin states. We administered three doses of r-metHuLeptin (0.1, 0.3, and 1.0 mg/kg) to healthy subjects to determine r-metHuLeptin pharmacokinetics in the fed state, to determine endogenous leptin production and clearance rates, and to study the effects of age, body mass index, gender, and race on r-metHuLeptin pharmacokinetics. We detected no dose-dependent effects on elimination half-life (t(1/2)), dose-normalized area under the curve (nAUC(0- infinity)), total body clearance (CL), or volume of distribution at steady state. The mean t(1/2), CL, and volume of distribution at steady state of r-metHuLeptin are 3.4 +/- 1.5 h, 79 +/- 16 ml/kg.h, and 150 +/- 39 ml/kg, respectively. Older subjects have a higher nAUC(0- infinity) (P = 0.003) and tend to have a decreased leptin production rate (Rsyn) and CL (P = 0.01). Increased body mass index is associated with higher baseline endogenous leptin levels (P < 0.0001), higher Rsyn (P < 0.0001), and longer t(1/2) (P = 0.008). Females have significantly greater baseline endogenous leptin levels and Rsyn than males (P < 0.0001). In summary, the leptin production rate is increased in females and with increasing adiposity, whereas leptin clearance is decreased with increasing adiposity, and nAUC(0- infinity) is increased with age. Elucidation of leptin pharmacokinetic parameters allows the accurate calculation of exogenous leptin replacement doses for humans in the fed state.
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Tejido Adiposo/metabolismo , Ingestión de Alimentos/fisiología , Leptina/análogos & derivados , Leptina/metabolismo , Leptina/farmacocinética , Obesidad/metabolismo , Adulto , Factores de Edad , Femenino , Humanos , Cinética , Leptina/efectos adversos , Leptina/biosíntesis , Masculino , Persona de Mediana Edad , Factores SexualesRESUMEN
Ghrelin, a stomach-derived orexigenic peptide, and leptin, a fat-derived anorexigenic hormone, act primarily in the hypothalamus to regulate energy homeostasis and have been reported to be regulated in opposite directions by acute and chronic changes in nutritional state. Nutritional, anthropometric, and hormonal predictors of circulating ghrelin have not yet been fully elucidated, and whether ghrelin is regulated by leptin in humans remains unknown. To address these questions, we performed cross-sectional and interventional studies. In 120 healthy men and women, ghrelin was negatively associated with leptin as well as overall and central adiposity, but not with total energy or specific macronutrient intake. The sexual dimorphism in ghrelin levels (higher levels in women than in men) and the negative correlation between ghrelin and insulin are largely mediated by central adiposity. In six lean men, complete fasting for 3 d resulted in a low leptin state without a major change in fat mass and abolished the meal-related secretory pattern of ghrelin without increasing 24-h ghrelin levels. In addition, recombinant human leptin administration in physiological and pharmacological doses did not regulate ghrelin over several hours to a few days. These data do not support a role for regulation of circulating ghrelin by leptin levels independently of changes in adiposity and suggest that the leptin and ghrelin systems for energy homeostasis function independently of each other in healthy humans.