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Historic and current land-use changes have altered the landscape for grassland biota, with over 90% of grasslands and savannas converted to agriculture or some other use in north temperate regions. Reintegrating grasslands into agricultural landscapes can increase biodiversity while also providing valuable ecosystem services. In contrast to their well-known importance in tropical and subtropical ecosystems, the role of ants in temperate grasslands is often underappreciated. As consumers and ecosystem engineers, ants in temperate grasslands influence invertebrate, plant, and soil microbial diversity and potentially alter grassland productivity. As common and numerically dominant invertebrates in grasslands, ants can also serve as important indicator species to monitor conservation and management practices. Drawing on examples largely from mesic, north temperate studies, and from other temperate regions where necessary, we review the roles of ants as consumers and ecosystem engineers in grasslands. We also identify five avenues for future research to improve our understanding of the roles of ants in grasslands. This includes identifying how grassland fragmentation may influence ant community assembly, quantifying how ant communities impact ecosystem functions and soil processes, and understanding how ant communities and their associated interactions are impacted by climate change. In synthesizing the role of ants in temperate grasslands and identifying knowledge gaps, we hope this and future work will help inform how land managers maximize grassland conservation value while increasing multiple ecosystem services and minimizing disservices.
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Hormigas , Animales , Biodiversidad , Ecosistema , Pradera , SueloRESUMEN
Significant toxicity from amphetamine and cathinone derivatives is being increasingly reported. We describe a series of self-reported exposures to 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25-I-NBOME or 25-I), a novel amphetamine derivative. Ten patients with an average age of 17 years presented to local emergency departments (EDs) in our community after ingestion and/or insufflation of a drug referred to as "25-I." Of 10 patients, 6 reported taking 25-I alone; other substances included ethanol; 2,5-dimethoxy-4-ethylphenethylamine; marijuana; and ketamine. Most common effects included tachycardia (90%), hypertension (70%), agitation (60%), and hallucinations (50%). The average heart rate was 123 beats per minute. Two patients were found in status epilepticus, and another was found unresponsive. One patient who had a seizure had multiple, discrete intraparenchymal hemorrhages and acute kidney injury. Six patients were admitted to the intensive care unit, two were treated in the ED and released, and 1 each was admitted to psychiatry or managed in a clinical decision unit and subsequently discharged. Three patients required emergent intubation, and all admitted patients (7/10) were given intravenous benzodiazepines for sedation. Urine and blood specimens were obtained from 1 patient, which showed analytic confirmation of 25-I. In addition to sympathomimetic effects, methoxy and other substituent groups impart serotonergic effects, resulting in hallucinogenic properties. 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine appears to be extremely potent with a reported "dose" of 500 µg resulting in increased potential for inadvertent overdose. This case series describes significant morbidity in a local cluster of young patients after self-reported use of 25-I, a newly identified drug of abuse.
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Drogas de Diseño/envenenamiento , Dimetoxifeniletilamina/análogos & derivados , Intoxicación/terapia , Adolescente , Cromatografía Líquida de Alta Presión , Dimetoxifeniletilamina/envenenamiento , Femenino , Humanos , Masculino , Espectrometría de Masas en Tándem , Adulto JovenRESUMEN
Every radio-loud quasar may have blazar activities, according to a unified scheme where the differences in both optical and radio observations of radio-loud quasars are the result of different viewing angles. We have predicted that blazars may be detected using emission line ratio variations caused by variable illumination of gas clouds in the broad emission line region. In a spectroscopic search of 62 quasars at a redshift of about 2, we have discovered large (>20%) variations of the emission line ratios, CIV/CIII] or CIV/Lyalpha, when compared with data taken more than 10 years ago. This result is consistent with our prediction and supports the unification scheme for radio-loud quasars.
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PURPOSE: Patients with recurrent glioblastoma (rGBM) have a poor prognosis, with survival ranging from 25 to 40 weeks. Antiangiogenic agents are widely used, showing a variable response. In this study, we explored the efficacy of carmustine plus bevacizumab (BCNU/Bev) for treating rGBM. METHODS/PATIENTS: In this study, we assessed 59 adult patients with histologically confirmed rGBM who were treated with BCNU/Bev as second-line regimen. The response rate (RR), progression-free survival (PFS) and overall survival (OS) were evaluated according to their molecular expression profile, including CD133 mRNA expression, MGMT methylation (pMGMT), PDGFR amplification, YKL40 mRNA expression, IDH1/2 condition, p53 and EGFRvIII mutation status. RESULTS: Median follow-up was 18.6 months, overall RR to the combination was 56.3%, and median PFS was 9.0 months (95% CI 8.0-9.9). OS from time of diagnosis was 21.0 months (95% CI 13.2-28.7) and from starting BCNU/Bev it was 10.7 months (95% CI 9.5-11.8). IDH1/2 mutations were found in 30.5% of the patients, pMGMT in 55.9% and high CD133 mRNA expression in 57.6%. Factors which positively affected PFS included performance status (p = 0.015), IDH+ (p = 0.05), CD133 mRNA expression (p = 0.009) and pMGMT+ (p = 0.007). OS was positively affected by pMGMT+ (p = 0.05). Meanwhile, YKL40 negatively affected PFS (p = 0.01) and OS (p = 0.0001). Grade ≥ 3 toxicities included hypertension (22%) and fatigue (12%). CONCLUSIONS: BCNU/Bev is a safe and tolerable treatment for rGBM. Patients with MGMT+/IDH+ derive the greatest benefit from the treatment combination in the second-line setting. Nonetheless, high YKL40 expression discourages the use of antiangiogenic therapy.
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Inhibidores de la Angiogénesis/uso terapéutico , Bevacizumab/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Carmustina/uso terapéutico , Glioblastoma/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Antígeno AC133/genética , Antígeno AC133/metabolismo , Adulto , Anciano , Inhibidores de la Angiogénesis/efectos adversos , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Bevacizumab/efectos adversos , Neoplasias Encefálicas/irrigación sanguínea , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidad , Carmustina/efectos adversos , Proteína 1 Similar a Quitinasa-3/genética , Colombia , Metilasas de Modificación del ADN/metabolismo , Enzimas Reparadoras del ADN/metabolismo , Esquema de Medicación , Femenino , Genes erbB-1 , Genes p53 , Glioblastoma/irrigación sanguínea , Glioblastoma/genética , Glioblastoma/mortalidad , Humanos , Isocitrato Deshidrogenasa/genética , Masculino , Metilación , Persona de Mediana Edad , Mutación , Recurrencia Local de Neoplasia/irrigación sanguínea , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/mortalidad , Supervivencia sin Progresión , ARN Mensajero/metabolismo , Receptores del Factor de Crecimiento Derivado de Plaquetas/genética , Análisis de Supervivencia , Proteínas Supresoras de Tumor/metabolismo , Adulto JovenRESUMEN
PURPOSE: Infections and deep vein thrombosis (DVT) after total hip arthroplasty (THA) are challenging problems for both the patient and surgeon. Previous studies have identified numerous risk factors for infections and DVT after THA but have often been limited by sample size. We aimed to evaluate the effect of operative time on early postoperative infection as well as DVT rates following THA. We hypothesized that an increase in operative time would result in increased odds of acquiring an infection as well as a DVT. METHODS: We conducted a retrospective analysis of prospectively collected data using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2006 to 2015 for all patients undergoing primary THA. Associations between operative time and infection or DVT were evaluated with multivariable logistic regressions controlling for demographics and several known risks factors for infection. Three different types of infections were evaluated: (1) superficial surgical site infection (SSI), an infection involving the skin or subcutaneous tissue, (2) deep SSI, an infection involving the muscle or fascial layers beneath the subcutaneous tissue, and (3) organ/space infection, an infection involving any part of the anatomy manipulated during surgery other than the incisional components. RESULTS: In total, 103,044 patients who underwent THA were included in our study. Our results suggested a significant association between superficial SSIs and operative time. Specifically, the adjusted odds of suffering a superficial SSI increased by 6% (CI=1.04-1.08, p<0.0001) for every 10-minute increase of operative time. When using dichotomized operative time (<90minutes or >90minutes), the adjusted odds of suffering a superficial SSI was 56% higher for patients with prolonged operative time (CI=1.05-2.32, p=0.0277). The adjusted odds of suffering a deep SSI increased by 7% for every 10-minute increase in operative time (CI=1.01-1.14, p=0.0335). No significant associations were detected between organ/space infection, wound dehiscence, or DVT and operative time either as continuous or as dichotomized. CONCLUSION: Prolonged operative times (>90min) are associated with increased rates of superficial SSIs, but not deep SSIs, organ/space infections, wound dehiscence, or DVT. LEVEL OF EVIDENCE: III.
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Artroplastia de Reemplazo de Cadera/efectos adversos , Artropatías/epidemiología , Tempo Operativo , Infección de la Herida Quirúrgica/epidemiología , Trombosis de la Vena/epidemiología , Adulto , Anciano , Bases de Datos Factuales , Femenino , Humanos , Artropatías/etiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Infección de la Herida Quirúrgica/etiología , Estados Unidos/epidemiología , Trombosis de la Vena/etiologíaRESUMEN
Thirteen protease inhibitor-naive patients with HIV-1 infection, and 12 patients with a median of 58 months prior treatment with saquinavir (SQV) monotherapy, were treated with SQV (400 mg twice daily) and ritonavir (RIT, 500 mg twice daily) in a study designed to assess the effect of prior treatment with SQV monotherapy on the antiretroviral activity of RIT-SQV combination therapy. Median baseline viral load and CD4+ cell counts were 155,000 and 262,000 copies/ml and 333 and 225 cells/mm3 in the naive and experienced groups, respectively. Mean viral load changes at 24 weeks were -1.63 and -0.27 log copies/ml in the naive and SQV-experienced groups, respectively (intent-to-treat analysis). Baseline genotype by point mutation assay and sequencing in the SQV-experienced group was highly predictive of virological response. Eight of 11 SQV-experienced patients had evidence of phenotypic resistance to RIT at baseline, despite previous treatment with SQV only. There was strong correlation between phenotypic resistance to RIT and the presence of the L90M mutation. We conclude that prolonged prior treatment with saquinavir monotherapy may produce cross-resistance to ritonavir and reduce the subsequent response to ritonavir-saquinavir in combination. In this study, both phenotypic resistance to ritonavir and presence of the L90M mutation predicted the viral load response to ritonavir-saquinavir.
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Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico , VIH-1/efectos de los fármacos , Ritonavir/uso terapéutico , Saquinavir/uso terapéutico , Adulto , Recuento de Linfocito CD4 , Estudios de Cohortes , Interacciones Farmacológicas , Farmacorresistencia Microbiana/genética , Quimioterapia Combinada , Femenino , Productos del Gen pol/genética , Infecciones por VIH/virología , VIH-1/genética , Humanos , Masculino , Persona de Mediana Edad , Mutación , Ritonavir/efectos adversos , Ritonavir/farmacocinética , Saquinavir/efectos adversos , Saquinavir/farmacocinética , Análisis de Secuencia de ADN , Carga ViralRESUMEN
OBJECTIVE: To investigate the relationship between serum vitamin A levels and conjunctival impression cytology and retinal whitening present in Malawian children with cerebral malaria. METHODS: Standard retinal examination and conjunctival impression cytology were performed at hospital admission on 101 consecutively admitted children with cerebral malaria. Blood samples were drawn from 56 children at 24 hours, frozen at -20 degrees C, and transported for assessment of vitamin A levels by high-performance liquid chromatography. Associations among fundus findings and vitamin A measurements were sought. RESULTS: The whitening of the retina that we have previously described in children with cerebral malaria was found to be associated with a mean+/-SD serum vitamin A level of 0.29+/-0.1 micromol/L, compared with a mean vitamin A level of 0.41+/-0.2 micromol/L in children without retinal whitening. Children with retinal whitening were 2.77 (95% CI, 1.06-7.3) times more likely to have abnormal conjunctival impression cytology results than those without whitening. No child had any clinical or ophthalmologic evidence of chronic vitamin A deficiency. CONCLUSIONS: The retinal whitening described in children with cerebral malaria is associated with low serum vitamin A levels and with abnormal conjunctival impression cytology results and may be due to acute vitamin A deficiency at the tissue level.
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Fondo de Ojo , Malaria Cerebral/sangre , Enfermedades de la Retina/sangre , Vitamina A/sangre , Niño , Preescolar , Cromatografía Líquida de Alta Presión , Conjuntiva/patología , Humanos , Lactante , Malaria Cerebral/complicaciones , Malaria Cerebral/patología , Malaui , Papiledema/sangre , Papiledema/complicaciones , Papiledema/patología , Enfermedades de la Retina/complicaciones , Enfermedades de la Retina/patología , Deficiencia de Vitamina A/sangre , Deficiencia de Vitamina A/complicacionesRESUMEN
The pathogenesis of cerebral malaria is poorly understood. Direct and indirect ophthalmoscope examinations of 141 Malawian children with strictly defined cerebral malaria revealed 2 distinct and prognostically significant findings: papilloedema and extramacular retinal oedema. The relative risk of death in patients with papilloedema was 6.7 times that in patients without papilloedema. Extramacular retinal oedema was associated with a 2.9 fold increase in the relative risk of dying. The mortality rate in patients with neither of these signs was only 1.3% compared to an overall mortality rate of 9.2%. The clinical and laboratory features associated with each of these ophthalmological findings were different, suggesting that there may be at least 2 different pathogenetic processes in patients with cerebral malaria.
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Malaria Cerebral/complicaciones , Enfermedades de la Retina/complicaciones , Glucemia/análisis , Temperatura Corporal , Niño , Preescolar , Edema/complicaciones , Fondo de Ojo , Humanos , Lactante , Malaria Cerebral/mortalidad , Papiledema/complicaciones , Valor Predictivo de las Pruebas , Pronóstico , Enfermedades de la Retina/mortalidad , Hemorragia Retiniana/complicaciones , Factores de RiesgoRESUMEN
OBJECTIVES: To examine the prevalence of resistance mutations and natural polymorphisms to reverse transcriptase (RT) and protease inhibitors in a cohort of patients with defined seroconversion dates. METHODS: Eligible patients were those attending an HIV centre in North London who seroconverted from HIV negative to positive status between 01/01/85 and 31/12/91 (n=104). Genotypic resistance analysis was performed on the first positive serum sample after seroconversion and before use of antiretroviral therapy using population-based sequencing of RT-PCR fragments and rule-based sequence interpretation (Vircogen). RESULTS: Protease and RT sequences were successfully amplified from only 37 (35.6%) of the 104 seroconverters. Only one patient who seroconverted in August 1991 showed any evidence of significant mutations in the RT region, and this was associated with resistance to zidovudine (ZDV) (215Y and 210W). An additional patient who seroconverted in July 1991 had a TOR mutation and was classified as having intermediate resistance to ZDV. No spontaneous mutations were detected in the protease region. CONCLUSIONS: Overall only 2 (5%) of these treatment-naïve individuals were infected with HIV variants resistant to ZDV. Although the data at present do not support the need for pretreatment genotyping, there is a need for continued surveillance of the frequency of resistance mutations in antiretroviral naïve patients since the introduction of highly active antiretroviral therapy.
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Fármacos Anti-VIH/farmacología , Farmacorresistencia Viral Múltiple , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Zidovudina/farmacología , Europa (Continente) , Variación Genética , Genotipo , VIH-1/genética , VIH-1/fisiología , Humanos , Londres , América del Norte , Prevalencia , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
It is estimated that approximately 50% of patients with cancer experience pain, and this percentage increases to 80% in patients with terminal cancer. Misconceptions and concerns of patients with cancer regarding the use of opioid analgesics have been identified as one of the major barriers to achieving optimal pain control. Misconceptions and concerns regarding addiction and tolerance to opioid analgesics and patients' desire to be "good" have been reported in the United States. The aim of this survey was to determine if similar misconceptions and concerns exist in Hong Kong Chinese patients with cancer. The results indicate that Hong Kong Chinese patients have the same concerns regarding the use of opioid analgesics. The respondents' fatalistic beliefs are a major hindrance to optimizing pain control, with 79% indicating that pain is an inevitable aspect of hospitalization because they believe that cancer pain cannot be relieved by medications. Fear of addiction was a major concern for 52% of the respondents, and about the same number of respondents believed that opioid analgesics should be administered only as a last resort. Regarding a desire to be "good," more patients reported that they would prefer to disturb nurses rather than physicians. It is desirable that culturally specific education programs be provided to dispel patient misconceptions and concerns regarding the use of opioid analgesics.
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Neoplasias/enfermería , Dolor Intratable/enfermería , Dolor Intratable/psicología , Rol del Enfermo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , China/etnología , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/etnología , Neoplasias/psicología , Dolor Intratable/etnología , Encuestas y CuestionariosRESUMEN
Post-traumatic stress disorder (PTSD) is one of the most disabling psychopathological conditions affecting the veteran population. An estimated 830,000 U.S. veterans currently have symptoms of chronic combat-related PTSD. No therapeutic approach has proven to be consistently effective in the management of combat-related PTSD. Behavior therapies with an exposure element have proven more effective than most other types of treatment, but a significant number of patients do not seem to benefit from them, possibly because of difficulties imagining, visualizing, or describing their traumatic experiences. In this article, we describe Virtual Vietnam, a set of two virtual environments we have developed for the treatment of combat-related PTSD, and its use as one component of a comprehensive treatment program.
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Metacarpal shaft fractures are common injuries that frequently unite with some shortening of the metacarpal. The aim of this study was to determine the effect of metacarpal shortening on digital flexion force. The index metacarpal of six cadaveric upper limbs was incrementally shortened. The flexion force produced at the end of the finger was recorded using a small load cell. At full extension, there was no significant change in flexion force produced regardless of the amount of shortening. However, at 50% aggregate flexion the loss of force became statistically significant at a shortening of 7.5 mm or more. At full digital flexion, the loss of force became statistically significant at shortening of 5 mm or more. At increasing amounts of finger flexion, progressive metacarpal shortening produces proportionally greater loss of fingertip flexion force. From this study it appears that metacarpal shortening of up to 5 mm should give minimal loss of finger flexion force.
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Dedos/fisiología , Huesos del Metacarpo/cirugía , Movimiento/fisiología , Osteotomía , Fenómenos Biomecánicos , Cadáver , Humanos , Tendones/fisiología , Tendones/cirugíaRESUMEN
CONTEXT: With regard to biological effects, the increasing number of early failure of metal-on-metal (MoM) hip arthroplasties and possible parenteral exposure to orthopedic metal alloys have caused concern for patients and providers alike. OBJECTIVE: We sought to characterize our outpatient clinical experience of patients with MoM and other forms of hip implants and associated serum/blood chromium and cobalt levels, with a focus on possible systemic sequelae. METHODS: This was an observational and retrospective chart review of consecutive patients presenting to two outpatient medical toxicology clinics from January 1, 2010-June 1, 2012 with history of hip implants. Presenting signs, symptoms, and interventions were reviewed. Available cobalt and chromium levels were summarized as median concentration with interquartile range. RESULTS: A total of 39 patients were analyzed; of the 39 patients, 26 had MoM hip implants while 13 did not. Twelve patients exhibited no symptoms and nine sought evaluation for fatigue while two other patients had been previously diagnosed with fibromyalgia. Tinnitus/hearing loss was also a frequent complaint noted in 12 patients (one presenting complaint), however there was no difference between the incidence of this symptom between the MoM and non-MoM groups. Three patients were provisionally diagnosed with demyelinating neuropathy with one patient demonstrating marked (subjective and objective) improvement after revision. Patients with MoM arthroplasties generally exhibit an approximately tenfold increase in metal ion levels than traditional arthroplasties. Finally, 20 (51.2%) patients had replacement or revision of their hip implant with subsequent decreases in metal ion levels. DISCUSSION: A majority of our patients had minor symptoms (fatigue and muscle aches) or no symptoms (n = 23 or 59%). Documented peripheral neurotoxicity is uncommon. The decision for hip revision solely for toxicologic reasons is rare and usually involves a multidisciplinary approach. CONCLUSION: Most patients seeking toxicologic referral may be minimally symptomatic and seek guidance regarding elevated blood or serum metal ions; however, solely toxicologic-based interventions are unusual. Revision was associated with a decrease in metal ion levels; however, subjective complaints did not correlate with metal ion levels.
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Artroplastia de Reemplazo de Cadera/efectos adversos , Prótesis de Cadera/efectos adversos , Prótesis Articulares de Metal sobre Metal/efectos adversos , Intoxicación/fisiopatología , Complicaciones Posoperatorias/fisiopatología , Falla de Prótesis/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Cromo/sangre , Cobalto/sangre , Estudios de Cohortes , Femenino , Intoxicación por Metales Pesados , Humanos , Illinois , Masculino , Metales Pesados/sangre , Persona de Mediana Edad , Servicio Ambulatorio en Hospital , Intoxicación/sangre , Intoxicación/etiología , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , VirginiaRESUMEN
Japanese encephalitis virus (JEV) is estimated to cause 3050,000 cases of encephalitis every year. The disease occurs mainly in rural Asia and is transmitted to humans from birds and pigs by mosquitoes of the genus Culex. JE is diagnosed with antibody testing of the serum and CSF, but this is not available in many hospitals. Neuroimaging abnormalities, particularly thalamic hypodensity on computed tomography (CT) and hyperintensity on T2 weighted magnetic resonance imaging (MRI) have been described in case studies, but their usefulness for diagnosing JE is not known. We have therefore evaluated the usefulness of neuroimaging (CT and MRI) for the diagnosis of JE. The findings of thalamic lesions were compared with the final serological diagnosis in a cohort of 75 patients (children and adults) with suspected CNS infections in Southern Vietnam, a JEV endemic area. Thalamic lesions on CT and/or MRI combined had sensitivity 23% (95% confidence interval 12.933.1%), specificity 100%, positive predictive value 100% and negative predictive value 42.1% (95% confidence interval 30.253.8%) for a diagnosis of JE in this cohort. Over time, the thalamic lesions resolved in some patients. One patient showed disappearance of lesions on CT followed by reappearance of the lesions some time later, known as the fogging effect. In this setting, the presence of thalamic abnormalities suggested the diagnosis of JE, but their absence did not exclude it.