Iodination-Group-Transfer Reactions to Generate Trisubstituted Iodoalkenes with Regio- and Stereochemical Control.

The regio- and stereodefined synthesis of trisubstituted alkenes remains a significant synthetic challenge. Herein, a method is developed for producing regio- and stereodefined trisubstituted iodoalkenes by diverting intermediates from an iodination-electrophilic-cyclization mechanism. Specifically, cyclized sulfonium ion-pair intermediates are diverted to alkenes by ring-opening with nucleophilic iodide. Alternatively, scavenging of the iodide by AgOTf prevents ring-opening, enabling isolation of the sulfonium ion-pair intermediate. Isolation of the ion pair enables access to complementary reactivity, including ring-opening by alternative nucleophiles (i.e., amines), yielding trisubstituted acyclic alkenes and an example acyclic tetrasubstituted alkene. X-ray crystallographic determination of reaction intermediates and products confirms that the initial electrophilic-cyclization step sets the stereo- and regiochemistry of the product. The products serve as synthetic building blocks by readily participating in downstream functionalization reactions, including oxidation, palladium-catalyzed cross-coupling, and nucleophilic displacement.

Repurposing π Electrophilic Cyclization/Dealkylation for Group Transfer.

A metal-free regio- and stereocontrolled group-transfer route toward the synthesis of trisubstituted alkenes is described. In this route, an electrophilic heterocyclization is followed by ring-opening group transfer. Specifically, a thioboration reaction transforms readily available alkynyl sulfide precursors into alkenyl boronates and alkenyl sulfides with defined regio- and stereochemistry in one synthetic step using commercially available B-chlorocatecholborane (ClBcat). Mechanistic studies identified the likely pathway as proceeding through zwitterionic rather than haloborated intermediates. The regio- and stereochemistry set in the initial cyclization step is preserved in the final acyclic alkene product, producing alkenes with up to four modifiable substituents with predictable regio- and stereochemistry. Downstream functionalization reactions showcase the versatility of the substitutions of the resulting alkenes. The mechanistic concept maps onto future reaction designs, given the abundance of known electrophiles and nucleophiles for electrophilic heterocyclization/dealkylation sequences.

A comparison of magnetic resonance elastography (MRE) to biomarker testing for staging fibrosis in non-alcoholic fatty liver disease (NAFLD).

Background: Non-alcoholic fatty liver disease (NAFLD) is the world's most prevalent chronic liver disease. In advanced stages, it is associated with significant morbidity and mortality. Magnetic resonance elastography (MRE) and scoring panels Fibrosis-4 (FIB-4) and NAFLD Fibrosis Score (NFS) are useful noninvasive alternatives to liver biopsy for fibrosis staging. Our study aimed to determine how well MRE corresponds with both FIB-4 and NFS at different stages of fibrosis. Methods: We performed a retrospective chart review of patients age ≥18 with NAFLD as their only known liver disease who underwent MRE within six months of a lab draw. MRE stratified patients into fibrosis stages using kPa values. FIB-4 categorized patients as Advanced Fibrosis Excluded, Further Investigation Needed or Advanced Fibrosis Likely. NFS categorized them as F0-2, Indeterminate or F3-4. MRE fibrosis staging was compared to FIB-4 and NFS for both ruling out advanced fibrosis and identifying advanced fibrosis/cirrhosis. Results: Overall, 193 patients met inclusion criteria. Our statistical analysis included calculating positive predictive values (PPVs) and negative predictive values (NPVs), which are the proportions of positive and negative fibrosis screening results that correspond to positive and negative MRE results respectively. NPV for FIB-4 (0.84) and NFS (0.89) in the 'rule out advanced fibrosis' category signify that 84% and 89% of respective biomarker scores correspond to MRE in early stage disease. The PPV for FIB-4 and NFS in the 'identify advanced fibrosis/cirrhosis' category signify 63% and 72% of respective biomarker scores correspond to MRE in late stage disease. Conclusions: FIB-4 and NFS scores indicating little to no fibrosis correspond extremely well with MRE, while scores suggesting advanced fibrosis/cirrhosis correspond less convincingly. MRE shows promise as an effective alternative to liver biopsy, however our study suggests FIB-4 and NFS alone may be sufficient for fibrosis staging, particularly in early stage NAFLD.

Anatomy of disturbed sleep in pallido-ponto-nigral degeneration.

OBJECTIVE: Pallido-ponto-nigral degeneration (PPND), caused by an N279K mutation of the MAPT gene, is 1 of a family of disorders collectively referred to as frontotemporal dementia and parkinsonism linked to chromosome 17. This study aims to characterize the nature of the sleep disturbance in PPND and compare these findings to those in other progressive neurological illnesses. Pathological findings are also provided. METHODS: Ten subjects were recruited from the PPND kindred; 5 affected and 5 unaffected. The subjects underwent clinical assessment, polysomnography, and wrist actigraphy. Available sleep-relevant areas (pedunculopontine/laterodorsal tegmentum, nucleus basalis of Meynert, thalamus, and locus ceruleus) of affected subjects were analyzed postmortem. RESULTS: The affected group's total sleep time was an average of 130.8 minutes compared to 403.6 minutes in the control group (p < 0.01). Initial sleep latency was significantly longer in affected subjects (range, 58-260 minutes vs 3-34 minutes). Affected subjects also had an increase in stage I sleep (8.5% vs 1%), and less stage III/IV sleep (8.5% vs 17%). At the time of autopsy, all cases had severe neuronal tau pathology in wake-promoting nuclei, as well as decreases in thalamic cholinergic innervations. There was no difference in orexinergic fiber density in nucleus basalis of Meynert or locus ceruleus compared to controls. INTERPRETATION: The PPND kindred showed severe sleep disturbance. Sleep abnormalities are common in neurodegenerative illnesses, but this is the first study of sleep disorders in PPND. Unlike most neurodegenerative conditions, PPND is characterized by decreased total sleep time, increased sleep latency, and decreased sleep efficiency, without daytime hypersomnolence.

Leveraging genomics to understand threats to migratory birds.

Understanding how risk factors affect populations across their annual cycle is a major challenge for conserving migratory birds. For example, disease outbreaks may happen on the breeding grounds, the wintering grounds, or during migration and are expected to accelerate under climate change. The ability to identify the geographic origins of impacted individuals, especially outside of breeding areas, might make it possible to predict demographic trends and inform conservation decision-making. However, such an effort is made more challenging by the degraded state of carcasses and resulting low quality of DNA available. Here, we describe a rapid and low-cost approach for identifying the origins of birds sampled across their annual cycle that is robust even when DNA quality is poor. We illustrate the approach in the common loon (Gavia immer), an iconic migratory aquatic bird that is under increasing threat on both its breeding and wintering areas. Using 300 samples collected from across the breeding range, we develop a panel of 158 single-nucleotide polymorphisms (SNP) loci with divergent allele frequencies across six genetic subpopulations. We use this SNP panel to identify the breeding grounds for 142 live nonbreeding individuals and carcasses. For example, genetic assignment of loons sampled during botulism outbreaks in parts of the Great Lakes provides evidence for the significant role the lakes play as migratory stopover areas for loons that breed across wide swaths of Canada, and highlights the vulnerability of a large segment of the breeding population to botulism outbreaks that are occurring in the Great Lakes with increasing frequency. Our results illustrate that the use of SNP panels to identify breeding origins of carcasses collected during the nonbreeding season can improve our understanding of the population-specific impacts of mortality from disease and anthropogenic stressors, ultimately allowing more effective management.

Prevalence of restless legs syndrome in blood donors.

Iron deficiency anemia has been linked to restless legs syndrome (RLS) and regular blood donation may lead to iron deficiency. It has been reported that blood donations may be associated with RLS. A recent study from Sweden found that 25% of the women donors were affected by RLS. However, this type of study has not been replicated in the United States. We conducted a study in our blood donation unit between September and October 2008. To identify those with RLS, we used the RLS diagnostic index questionnaire by Benes et al. The proportion of blood donors with RLS was estimated and the number of blood donations and hemoglobin levels were compared according to RLS status. One hundred and fifty one patients were interviewed; 7 patients who donated only platelets were excluded, leaving 144 patients for analysis. There were 13 (9.0%, 95% confidence interval [CI]: 4.9-14.9%) patients with RLS. Of these, 7 (4.9%, 95% CI: 2.0-9.8%) had possible RLS and 6 (4.2%, 95% CI: 1.5-8.9%) had major or clinically relevant RLS. There was no dramatic association between RLS and number of blood donations or hemoglobin level (all P >or= 0.21). In our sample of blood donors in the United States, the prevalence of major RLS was 4%. We could not demonstrate an association between RLS and the frequency of blood donation or hemoglobin level in our relatively small sample; a larger sample is needed to better identify any associations.

Efficacy of delayed administration of post-chemotherapy granulocyte colony-stimulating factor: evidence from murine studies of bone marrow cell kinetics.

The optimal schedule of post-chemotherapy granulocyte colony-stimulating factor (G-CSF) administration has not been determined. G-CSF is customarily started 24 hours after chemotherapy; however, clinical data demonstrated that delaying G-CSF until 5 days after completion of chemotherapy has not resulted in a longer duration of neutropenia. Here, we examined the optimal timing of post-chemotherapy G-CSF administration in a mouse model, to show that delayed administration does not postpone the appearance of mature granulocytes in the peripheral blood. We also investigated the mechanism of decreased efficacy of the early G-CSF application after chemotherapy by characterizing the changes in bone marrow cellular composition. To our knowledge, we demonstrate for the first time, that early after chemotherapy, the bone marrow is predominantly composed of mature residual granulocytes and very few progenitors and precursors, on which G-CSF would act to generate granulocytes. The point when immature progenitors reappear does not occur in murine bone marrow until 48 hours after a single dose of cyclophosphamide. Our results indicate that the bone marrow cellular composition early after discontinuation of chemotherapy is not optimal for G-CSF action on acceleration of myeloid recovery. Given the high cost of G-CSF prophylaxis, its delayed administration may potentially result in substantial economic benefits.

Prevalence of restless legs syndrome among native South Americans residing in coastal and mountainous areas.

OBJECTIVE: To determine the prevalence of restless legs syndrome (RLS) in native South Americans and identify the impact of geographic location. PARTICIPANTS AND METHODS: An epidemiological telephone survey of RLS symptoms involving natives from coastal and mountainous areas was performed during July 2, 2004, through September 28, 2004. The process consisted of 2 phases: the creation of the epidemiological instrument and the telephone survey. RESULTS: Five hundred adults, 250 from the mountainous regions and 250 from the coastal region (190 men and 310 women; age range, 25-85 years) were interviewed and subsequently divided on the basis of International Restless Legs Syndrome Study Group criteria into those who had RLS (RLS+ group) and those who did not (RLS- group). Ten (2.0%) had RLS. The overall rate of RLS in adults living in the mountainous region at 2816 m above sea level (3.2% [8/250]) was significantly higher than that for adults living in the coastal region at 4 m above sea level (0.80% [2/250]; P = .002). The mean age of the RLS+ group was 49.5 years (SD, 15.20 years; range, 25-85 years). CONCLUSION: Native South American adults have a prevalence of RLS well below that reported in populations with European ancestry but similar to that in Asian and Turkish populations. Furthermore, in Ecuador, geographic differences were identified in areas of similar population density.

Pergolide-associated valvular heart disease.

Pergolide is an ergot derivative dopamine agonist used in the treatment of Parkinson's disease and restless legs syndrome. Ergot derivatives are known to be associated with fibrotic conditions, including a carcinoid-like, fibrotic, valvular heart disease (VHD). Recently, pergolide was identified in association with the development of VHD. This article includes a summary of the literature published on pergolide-associated VHD, a description of the potential mechanisms of drug-induced VHD, and the clinical implications for the management of patients taking pergolide.

Valvular heart disease in patients taking pergolide.

OBJECTIVE: To Investigate the frequency of valvular heart disease in patients taking pergolide. PATIENTS AND METHODS: The medical records of patients seen at the Mayo Clinic in Jacksonville, Fla, between 1998 and 2003 were searched electronically for the word pergolide and the presence of a 2-dimensional echocardiogram. Patients who had not taken pergolide before undergoing echocardlography served as the control group. Echocardiograms were reviewed for the presence of valvular regurgitation. The frequency of valvular disease in patients taking pergolide was calculated and compared with controls. Associations with dosage and years of treatment also were examined. RESULTS: Fifty-five patients made up the pergolide group, and 63 served as controls. When looking at aortic regurgitation (AR) of any degree, 45% of patients in the pergolide group had AR, compared with 21% of controls (P = .006). The frequency of moderate to severe valvular regurgitation in the pergolide group was 11% (95% confidence interval [CI], 4%-22%), 13% (95% CI, 5%-24%), and 13% (95% CI, 5%-24%) for the tricuspid, mitral, and aortic valves, respectively. No statistical difference was identified in the frequency of moderate to severe valvular regurgitation (mitral, tricuspid, or aortic) when compared with controls. There was marginal evidence of an association between a higher daily dosage of pergolide and moderate to severe AR (P = .05). CONCLUSION: The frequency of AR appears to be Increased in patients taking pergolide. Our study suggests that if a cause-effect relationship exists between pergolide and valvular heart disease, it likely occurs at a low but clinically important Incidence and may be associated with dosage.

Acquisition of Fas resistance by Fas receptor mutation in a childhood B-precursor acute lymphoblastic leukemia cell line, MML-1.

Programmed cell death, or apoptosis, is a physiological means of eliminating unwanted cells and maintaining immune homeostasis. One of the primary mechanisms is the Fas (CD95)/Fas ligand system. Its inactivation in normal cells and malignant cells may be involved in malignant trans-formation and refractory clinical course, respectively. We established a Fas resistant clone and evaluated the molecular basis for its mechanism of resistance. The Fas-sensitive leukemia cell line, MML-1, was established from a child with B-precursor acute lymphoblastic leukemia. A Fas resistant clone, MML-1R, was obtained by co-culture selection with anti-Fas antibody CH-11. Flow cytometry analysis showed both cell lines had equivalent expression of cell surface CD13, 15, 19, 22 and Fas receptor. Western blot analysis revealed equal expression of FADD (Fas-associated death domain protein), caspase-3 and -8. MML-1 was quite sensitive to both CH-11 and etoposide-induced apoptotis. By contrast, MML-1R had similar sensitivity to etoposide but no response to CH-11. Fas receptor mutation analysis showed a heterozygous death domain A --> G point mutation at 1009 bp, causing a switch from glutamine to glycine at amino acid 256. Immunoprecipitation assay showed decreased binding of Fas to FADD. We also found that etoposide bypassed Fas-FADD interaction in MML-1R by activating caspase-8 and caspase-3. These results indicate that Fas resistance can result from mutations of the gene encoding the Fas receptor which result in decreased FADD binding, thereby blocking formation of the death inducing signaling complex. Screening for similar Fas mutations in therapy resistant malignancies would lead to a better understanding of tumorigenesis and recurrence.

Sleep deprivation.

The occurrence of chronic sleep deprivation in the population is commonplace. Both duration and quality of sleep are important to assess when evaluating a patient who has sleep complaints. Excessive sleepiness and decreased psychomotor performance have been demonstrated after sleep deprivation. Sleep loss may impact mood, autonomic function, and the immune system. Sleep-deprived adults may have impaired job performance and are prone to motor vehicle accidents. Simple interventions to ensure adequate sleep can help avoid these hazards.

Survey of restless legs syndrome in a pulmonary hypertension population.

INTRODUCTION: The prevalence of restless legs syndrome (RLS) varies from 5% to 24% in the general population and is associated with a variety of medical disorders. However, the association between RLS and pulmonary hypertension (PH) is unknown. OBJECTIVES: To determine the prevalence of RLS in PH patients. METHODS: A cross-sectional questionnaire was given to patients with PH who attended the Pulmonary Hypertension Association conference. We used the RLS Diagnostic Index questionnaire. Demographic data included age, gender, height, weight, body mass index (BMI), medication list, PH World Health Organization (WHO) diagnosis group and current WHO functional class. RESULTS: The study included 128 PH patients. Most were females (86.8%) with a mean age of 49.68 years [standard deviation (SD) 14.24]. The mean BMI was 31.3 (SD 20.46). One hundred and twenty-one patients (93.75%) were classified as WHO group 1 (pulmonary arterial hypertension). Three patients were identified in WHO group 3 (hypoxemic states), four patients in group 4 (chronic thromboemboli) and one patient in group 5 (2.3%, 3.1% and 0.8%, respectively). Definite RLS was found in 16 of 128 patients with PH resulting in a prevalence of 12.5%, possible RLS in 39 of 128 patients (30.46%) and no RLS in 73 (57.03%) patients. CONCLUSION: The prevalence of RLS is not increased in PH. There is a high prevalence of possible RLS in our study. The overall prevalence of combined definite and possible RLS is significant. Future research is needed to assess more patients with PH and the association or correlation with RLS.

Sleep patterns of cyclic parenteral nutrition, a pilot study: are there sleepless nights?

BACKGROUND: Cyclic home parenteral nutrition (HPN) is 1 of the few medical therapies given during normal nocturnal sleep hours, and it is possible that infusion may alter normal sleep patterns. The aim of this pilot study was to evaluate the sleep patterns of 5 patients receiving HPN. METHODS: An Epworth sleep questionnaire was completed and wrist Actigraph data were collected before admission to the sleep laboratory. Formal overnight polysomnography was then preformed for 3 consecutive nights. The first night served as the acclimatization period. On the second and third nights, patients were randomized to receive either no infusion or infusion of their standard parenteral nutrition. Results were reported as the median and range and were compared with historical aged-matched controls. RESULTS: Five patients (3 women and 2 men) with a mean age of 61 years (40 to 73 years) were studied. Patients had been HPN-dependent for a median of 23 months (4 to 60 months). Patients were receiving HPN because of short bowel syndrome (2), chronic pancreatitis (2), and intestinal pseudoobstruction (1). A 1.5-liter HPN formula, infused over 10 hours, included approximately 25 kcal/kg/d with 30% lipid and 1.0 to 1.5 g/kg/d of protein. All solutions included multiple trace elements and standard multivitamins. During total parenteral nutrition (TPN) infusion, the percent of sleep efficiency was higher than without infusion, 81% versus 72%. Sleep efficiency in age-matched controls was approximately 88%. Sleep latency was longer in patients compared with controls, and longer in patients during infusion than without infusion, 35 versus 28 minutes. During TPN infusion, the percent of stage-1 (2%), stage-2 (52%), slow-wave (24%) and random eye movement (REM) sleep (21%) was similar to values during the night without infusion. Controls had lower slow-wave and REM times. The median Epworth sleep score was 3, which is the normal reported range. CONCLUSIONS: Although sleep quality is reduced in patients receiving HPN compared with aged-matched controls, sleep quality does not seem to be negatively effected by cyclic HPN infusion.

Laser Scanning Cytometry for selection of green fluorescent protein transgenic mice using small number of blood cells.

A Laser Scanning Cytometry-based method was developed for identification of transgenic mice expressing green fluorescent protein (GFP) using minute amounts of peripheral blood. The difference between the autofluorescence of cells not expressing GFP and the fluorescence of GFP expressing cells after excitation with Ar-ion laser (wavelength 488 nm) and detection of emitted fluorescent light in the green channel was high enough for unambiguous identification of the GFP expressing mice. The sensitivity of this method was estimated 1:10(4) for detection of rare GFP expressing cells under the conditions used. This sensitivity should be sufficient for many studies on microchimerism. Because of the possibility for relocation of the cells, this method will be particularly useful for characterizing the cells with high GFP expression using other markers of cell phenotype or conventional morphological analysis.

A 60-year-old woman with PET scan-avid lung nodules and a history of a ruptured silicone breast implant.

A 60-year-old woman was referred to the pulmonary clinic for evaluation of lung nodules. Her medical history was notable for hypothyroidism, anxiety, and a ruptured breast implant for which incomplete surgical resection and evacuation had been performed 10 years previously. She was a lifelong nonsmoker and worked as a gym instructor. The patient denied occupational exposures and had not traveled recently. Medications included levothyroxine and alprazolam. Except for a 1-month history of occasional dry cough, the review of systems was negative. The patient's physician queried whether the previously ruptured silicone breast implant may have played a role in the genesis of the nodules and referred the patient to our institution for further management. The lack of systemic symptoms relative to the degree of lung involvement provided an early diagnostic clue.

Sleep disorders and the eye.

During the past decade, associations between sleep disorders and certain ophthalmologic disorders have been increasingly recognized. To review the literature on these important associations, we conducted a PubMed search using combinations of the following terms: sleep disorders, sleep apnea, circadian rhythm disorder, continuous positive airway pressure, eye disease, floppy eyelid syndrome, glaucoma, ischemic optic neuropathy, papilledema, nocturnal lagophthalmos, and vision loss. We limited our search to articles published in English that involved human participants. All available dates were included. One of the most common sleep disorders, obstructive sleep apnea, has been associated with a variety of eye diseases, including glaucoma, nonarteritic anterior ischemic optic neuropathy, floppy eyelid syndrome, papilledema, and continuous positive airway pressure-associated eye complications. Nocturnal lagophthalmos manifests during sleep and is defined as the failure to fully close the eyelids at night. Finally, blindness is associated with increased risk of circadian rhythm disorders. On the basis of the existing published literature, we discuss these rarely recognized associations, potential pathophysiologic mechanisms, and the effect these associations have on the clinical management of patients. The knowledge of these associations is important for the primary care physician, ophthalmologist, and sleep physician so that underlying sleep disorders or ophthalmologic disorders can be detected.

Zinc deficiency in Mexican American children: influence of zinc and other micronutrients on T cells, cytokines, and antiinflammatory plasma proteins.

BACKGROUND: The Third National Health and Nutrition Examination Survey suggested some Mexican American children are at risk of zinc deficiency. OBJECTIVE: We measured the effects of zinc and micronutrients or of micronutrients alone on indexes of cell-mediated immunity and antiinflammatory plasma proteins. DESIGN: Subjects (n = 54) aged 6-7 y were randomly assigned and treated in double-blind fashion in equal numbers with 20 mg Zn (as sulfate) and micronutrients or with micronutrients alone 5 d/wk for 10 wk. RESULTS: Before treatment the mean +/- SD plasma zinc was 14.9 +/- 1.7 micromol/dL and the range was within the reference; hair zinc was 1.78 +/- 0.52 micromol/g and 41.6% were < or =1.68 micromol/g; serum ferritin was 25.7 +/- 18.6 microg/L and 50.0% were < or =20 microg/L. The zinc and micronutrients treatment increased the lymphocyte ratios of CD4(+) to CD8(+) and of CD4(+)CD45RA(+) to CD4(+)CD45RO(+), increased the ex vivo generation of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), decreased the generation of interleukin-10 (IL-10), and increased plasma interleukin-1 receptor antagonist (sIL-1ra) and soluble tumor necrosis factor receptor 1 (sTNF-R1). Micronutrients alone increased the ratio of CD4(+) to CD8(+) but not of CD4(+)CD45RA(+) to CD4(+)CD45RO(+), increased IFN-gamma but had no effect on IL-2 or IL-10, and increased sIL-1ra but not sTNF-R1. Efficacy of zinc and micronutrients was greater than micronutrients alone for all indexes except the ratio of CD4(+) to CD8(+), which was affected similarly. CONCLUSIONS: Before treatment, concentrations of hair zinc in 41.6% of subjects and serum ferritin in 50% were consistent with the presence of zinc deficiency. The greater efficacy of the zinc and micronutrients treatment compared with micronutrients alone supports this interpretation.

Increased lymphocyte Fas expression and high incidence of common variable immunodeficiency disorder in childhood Evans' syndrome.

Evans' syndrome (ES) is characterized by autoimmune hemolytic anemia and thrombocytopenia and has been associated with immune deficiency and lymphoproliferation in some cases. Abnormalities of Fas-mediated apoptosis have been reported in various immune dysregulation disorders associated with autoimmunity and lymphoproliferation. We measured lymphocyte Fas expression and Fas-mediated T lymphocyte apoptosis in 7 children with ES, 7 with acute idiopathic thrombocytopenic purpura (ITP) and 9 with non-immune-mediated disorders. Patients with ES had higher Fas expression on peripheral blood T and B lymphocytes (P<0.001 and P=0.046, respectively) and increased Fas-mediated elimination of activated T lymphocytes compared with the control groups. While two ES patients had panhypogammaglobulinemia at testing, three more developed it later, reaching a frequency of 83%. Some children with ES have increased lymphocyte Fas expression and Fas-mediated T lymphocyte apoptosis and these may be early signs of common variable immunodeficiency disorder in ES.