Retinal oximetry and fractal analysis of capillary maps in sickle cell disease patients and matched healthy volunteers

Graefe's Archive for Clinical and Experimental Ophthalmology - Fractal analysis can be used to quantitatively analyze the retinal microvasculature and might be a suitable method to quantify...     

Outcomes of Single‐Stage Compared to Two‐Stage Basilic Vein Transposition Fistulae

Basilic vein transposition (BVT) fistulae are increasing in prevalence in the United States. We examined outcomes of BVT fistulae created in a single stage compared to those created in two stages. Prospective QA databases identified a consecutive cohort of 144 patients with BVT fistulae. Of these, 42% were created in one stage and 58% in two stages. Fistula maturation rates, mean time to fistula use and intensity of percutaneous interventions were compared; patency rates were compared from time of first intervention. Maturation rates (including assisted maturation) were 90% among 1‐stage and 75% among 2‐stage BVT (p = 0.02). Mean time to initiation of fistula use was 142 days (1‐stage) and 146 days (2‐stage) (p = 0.92). Intensity of percutaneous interventions was 1.84/patient‐year of dialysis (PYD) (1‐stage) and 2.15/PYD (2‐stage) (p = 0.57). Secondary patency at 1, 2, 3, and 4 years for 1‐stage BVT was 86%, 75%, 69%, and 57%; secondary patency at 1, 2, 3, and 4 years for 2‐stage BVT was 76%, 71%, 49%, and 25%, respectively (p = 0.12). BVT creation in two stages confers only a modest reduction in maturation rates and secondary patency and therefore should be considered over a synthetic graft in patients with basilic veins deemed inadequate for 1‐stage BVT.     

Clinical predictors of success and failure for lumbar facet radiofrequency denervation

OBJECTIVE: To determine the clinical factors associated with the success and failure of radiofrequency denervation of the lumbar facet joints. METHODS: Clinical data were garnered from 3 academic medical centers on 192 patients with low back pain who underwent radiofrequency denervation after a positive response to diagnostic blocks. Success was defined as >/=50% pain relief lasting at least 6 months. Factors evaluated for their association with outcome included duration of pain, opioid use, symptom location, paraspinal tenderness, pain exacerbated by extension/rotation (ie, facet loading), MRI abnormalities, diabetes, smoking, scoliosis, obesity, prior surgery and levels treated. RESULTS: The only factor associated with a successful outcome was paraspinal tenderness. Variables that correlated with treatment failure were 'facet loading,' long duration of pain, and previous back surgery. CONCLUSIONS: It is counterproductive to use 'facet loading' as the sole basis for choosing patients for facet interventions. In patients at high risk for treatment failure, taking additional steps to reduce the rate of false-positive screening blocks may improve outcomes.     

The Maladaptive Renal Response to Secondary Hypocapnia during Chronic HCl Acidosis in the Dog

It has generally been thought that homeostatic mechanisms of renal origin are responsible for minimizing the alkalemia produced by chronic hypocapnia. Recent observations from this laboratory have demonstrated, however, that the decrement in [HCO(-) (3)], which "protects" extracellular pH in normal dogs, is simply the by-product of a nonspecific effect of Paco(2) on renal hydrogen ion secretion; chronic primary hypocapnia produces virtually the same decrement in plasma [HCO(-) (3)] in dogs with chronic HCl acidosis as in normal dogs (Delta[HCO(-) (3)]/DeltaPaco(2) = 0.5), with the result that plasma [H(+)] in animals with severe acidosis rises rather than falls during superimposed forced hyperventilation.This observation raised the possibility that the secondary hypocapnia which normally accompanies metabolic acidosis, if persistent, might induce an analogous renal response and thereby contribute to the steady-state decrement in plasma [HCO(-) (3)] observed during HCl feeding. We reasoned that if sustained secondary hypocapnia provoked the kidney to depress renal bicarbonate reabsorption, the acute salutary effect of hypocapnia on plasma acidity might be seriously undermined.To isolate the possible effects of secondary hypocapnia from those of the hydrogen ion load, per se, animals were maintained in an atmosphere of 2.6% CO(2) during an initial 8-day period of acid feeding (7 mmol/kg per day); this maneuver allowed Paco(2) to be held constant at the control level of 36 mm Hg despite the hyperventilation induced by the acidemia. Steady-state bicarbonate concentration during the period of eucapnia fell from 20.8 to 16.0 meq/liter, while [H(+)] rose from 42 to 55 neq/liter. During the second phase of the study, acid feeding was continued but CO(2) was removed from the inspired air, permitting Paco(2) to fall by 6 mm Hg. In response to this secondary hypocapnia, bicarbonate concentration fell by an additional 3.0 meq/liter to a new steady-state level of 13.0 meq/liter. This reduction in bicarbonate was of sufficient magnitude to more than offset the acute salutary effect of the hypocapnia on plasma hydrogen ion concentration; in fact, steady-state [H(+)] rose as a function of the adaptive fall in Paco(2), Delta[H(+)]/Delta Paco(2) = -0.44. That the fall in bicarbonate observed in response to chronic secondary hypocapnia was the result of the change in Paco(2) was confirmed by the observation that plasma bicarbonate returned to its eucapnic level in a subgroup of animals re-exposed to 2.6% CO(2).These data indicate that the decrement in plasma [HCO(-) (3)] seen in chronic HCl acidosis is a composite function of (a) the acid load itself and (b) the renal response to the associated hyperventilation. We conclude that this renal response is maladaptive because it clearly diminishes the degree to which plasma acidity is protected by secondary hypocapnia acutely. Moreover, under some circumstances, this maladaptation actually results in more severe acidemia than would occur in the complete absence of secondary hypocapnia.     

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.     

Comorbidity of fibromyalgia and psychiatric disorders

There are mounting data supporting comorbidity of fibromyalgia syndrome (FMS) and psychiatric conditions. These include depression, panic disorders, anxiety, and post-traumatic stress disorder (PTSD). The nature of the relationship between depression and FMS is not fully understood, and it was hypothesized that chronic pain causes depression, or vice versa, and that chronic pain syndromes are variants of depression. A link between PTSD symptoms and FMS has been reported, and both conditions share similar symptomatology and pathogenetic mechanisms. Assessment of comorbid psychiatric disorders in FMS patients has clinical implications because treatment in these patients should focus both on physical and emotional dimensions of dysfunction.     

Fixed drug eruption of the scrotum due to methylphenidate.

OBJECTIVE: To report two cases of fixed drug eruption induced by methylphenidate. CASE SUMMARY: Two children with attention deficit disorder treated with methylphenidate as a simple drug developed fixed drug eruption of the scrotum. Drug discontinuation was followed by a complete resolution of the skin eruption. Rechallenge resulted in the same drug rash. Macrophage migration-inhibiting factor (MIF) assay with methylphenidate was positive. DISCUSSION: The pathogenesis of fixed drug eruption and the role of MIF assay in the diagnosis of adverse drug reaction is discussed. CONCLUSIONS: Fixed drug rash induced by methylphenidate is a possible but rare phenomenon.     

ASMBS pediatric metabolic and bariatric surgery guidelines, 2018

The American Society for Metabolic and Bariatric Surgery Pediatric Committee updated their evidence-based guidelines published in 2012, performing a comprehensive literature search (2009–2017) with 1387 articles and other supporting evidence through February 2018. The significant increase in data supporting the use of metabolic and bariatric surgery (MBS) in adolescents since 2012 strengthens these guidelines from prior reports. Obesity is recognized as a disease; treatment of severe obesity requires a life-long multidisciplinary approach with combinations of lifestyle changes, nutrition, medications, and MBS. We recommend using modern definitions of severe obesity in children with the Centers for Disease Control and Prevention age- and sex-matched growth charts defining class II obesity as 120% of the 95th percentile and class III obesity as 140% of the 95th percentile. Adolescents with class II obesity and a co-morbidity (listed in the guidelines), or with class III obesity should be considered for MBS. Adolescents with cognitive disabilities, a history of mental illness or eating disorders that are treated, immature bone growth, or low Tanner stage should not be denied treatment. MBS is safe and effective in adolescents; given the higher risk of adult obesity that develops in childhood, MBS should not be withheld from adolescents when severe co-morbidities, such as depressed health-related quality of life score, type 2 diabetes, obstructive sleep apnea, and nonalcoholic steatohepatitis exist. Early intervention can reduce the risk of persistent obesity as well as end organ damage from long standing co-morbidities.     

Recent alcohol use prolongs hospital length of stay following lung transplant

Little is known about the alcohol habits of people with advanced lung disease. Following lung transplantation, patients are asked to abstain from or minimize alcohol use. The aim of this investigation was to assess alcohol use in a cohort of patients with advanced lung disease undergoing evaluation for lung transplant. This is a prospective observational investigation comparing patient self‐report of alcohol use with their responses on the Alcohol Use Disorders Identification Test (AUDIT), and alcohol biomarkers collected at the time of transplant. There were 86 included in the cohort, 34% currently using alcohol, 13% had AUDIT scores >3, and 10% had positive results for alcohol biomarkers at the time of transplantation. Patients with evidence of recent alcohol use prior to lung transplant surgery had a 1.5‐fold increase in hospital length of stay following lung transplant (P = .028), spent 3 times as long on mechanical ventilation after transplant, and required intensive care unit monitoring nearly 3 times longer than those without recent alcohol use (P = .008). There were no differences in primary graft dysfunction, although several patients with recent alcohol use had post‐transplant atrial arrhythmias, acute kidney injury, and acute cellular rejection. Abstaining from alcohol use may optimize outcomes following lung transplant.