Correlated flickering of erythrocytes membrane observed with dual time resolved membrane fluctuation spectroscopy under different D-glucose concentrations

A correlated human red blood cell membrane fluctuation dependent on D-glucose concentration was found with dual time resolved membrane fluctuation spectroscopy (D-TRMFS). This new technique is a modified version of the dual optical tweezers method that has been adapted to measure the mechanical properties of red blood cells (RBCs) at distant membrane points simultaneously, enabling correlation analysis. Mechanical parameters under different D-glucose concentrations were obtained from direct membrane flickering measurements, complemented with membrane fluidity measurements using Laurdan Generalized Polarization (GP) Microscopy. Our results show an increase in the fluctuation amplitude of the lipid bilayer, and a decline in tension value, bending modulus and fluidity as D-glucose concentration increases. Metabolic mechanisms are proposed as explanations for the results.

Ipilimumab/nivolumab-induced pseudolymphoma in a patient with malignant melanoma

Combination therapy with ipilimumab and nivolumab is an adjuvant treatment approach for metastatic melanoma that boasts increased 3-year survival when compared with a single immunotherapy agent. Combination therapy, however, is associated with increased toxicities, especially cutaneous side-effects. Here we present a patient with metastatic melanoma and a sudden eruption of painful nodules on the face and arms 10 days after the administration of the fourth dose of combination ipilimumab/nivolumab. Biopsies demonstrated lymphoid hyperplasia, not clinically or pathologically consistent with an infectious, malignant or autoimmune etiology; a diagnosis of pseudolymphoma secondary to ipilimumab/nivolumab was made. After a steroid taper, the lesions resolved, and the patient was restarted on nivolumab monotherapy 2 weeks later without recurrence of symptoms or disease.

Characterisation and diagnosis of ulcers in inpatient dermatology consultation services: A multi-centre study

Accurate and prompt diagnosis of skin ulcers is critical to optimise management; however, studies in hospitalised patients are limited. This retrospective review of dermatologic consultations included 272 inpatients with skin ulcers between July 2015 and July 2018 in four U.S. academic hospitals. The median age was 54 years and 45% were male. In 49.3% of the patients, skin ulcers were considered the primary reason for admission. Ulcers of 62% were chronic and 49.6% were located on the lower extremities. Pyoderma gangrenosum (17.3%), infection (12.5%), and exogenous causes (11.8%) were the leading aetiologies; 12% remained diagnostically inconclusive after consultation. Diagnostic agreements pre-dermatology and post-dermatology consult ranged from 0.104 (n = 77, 95% CI 0.051-0.194) to 0.553 (n = 76, 95% CI 0.440-0.659), indicating poor-modest agreement. This study highlights the diagnostic complexity and relative incidences of skin ulcers in the inpatient setting.

Chemical pharmacotherapy options for managing adult acne

INTRODUCTION

The incidence of adult acne is increasing worldwide. Despite clinical overlap with conventional acne, it has distinct features. Areas covered: A literature search of English-language review articles, randomized control studies and retrospective studies conducted over the past 30 years was performed using PubMed and Google Scholar. Search terms included acne, adult, topical medication, oral medication and skin of color. We highlight important clinical features and treatment modalities pertinent to the evaluation and management of adult acne. Given the relative dearth of literature detailing treatment options specific to adult acne, we offer expert opinion regarding management of the condition especially in special populations such as skin of color and pregnancy. Expert Opinion: It is unclear whether adult acne represents a distinct entity or a continuum of adolescent disease. Providers may opt to use topical medication as first-line, but should have a low threshold for switching to systemic therapy given the magnitude of psychosocial and emotional burden associated with the condition.

Distant recurrence risk with prospective use of the 21-gene assay at a single institution

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Background: Distant recurrence (DR) is the cause of most breast cancer deaths. The 21-gene assay (ODX) Recurrence Score (RS) result predicts both 5 and 10-yr DR risk and can guide adjuvant chemotherapy (CT) recommendations to mitigate this risk. This study analyzed the use of the RS result to guide adjuvant treatment decisions in a large single-institution, prospective cohort of patients (pts). Methods: This is an IRB-approved review of a prospective database of pts receiving ODX on an initial primary breast cancer. Data collected included demographics, primary operation, margin status, receptor status, RS, adjuvant treatment, recurrence, and survival. Pts were stratified as low risk (RS < 18), intermediate risk, or high risk (RS > 30). The primary analysis computed Kaplan-Meier estimates for rate of DR at 5 yrs when pts were stratified by RS. Results: From 2003 to 2009, a RS result was obtained on 606 pts. Median follow up was 2.9 yrs (0.1-9.7) and median age was 58 yrs (27-84). Median RS result was 16 (0-63); 344(57%) pts were low, 212(35%) intermediate, 50(8%) high. Endocrine therapy was given to 92.4%, 94.3%, and 87.5% low, intermediate, and high risk pts, respectively. Adjuvant CT was given to 8.6%, 47.6%, and 70.8% low, intermediate, and high risk pts, respectively. There were 8 DR events with 1.8% 5-yr estimated risk of DR. The 5-yr estimated risk of DR was 0.7% for low risk (344) pts, 3.4% for intermediate risk (211) pts, and 2.6% for high risk (50) pts. Among node negative [N(-)] pts (502), the 5-yr estimated risk of DR was 0.8% for low risk (287) pts, 3.7% for intermediate risk (174) pts, and 3.3% for high risk (41) pts. Among node positive [(N+)] pts (54) there was only 1 DR, which was in a high risk pt. Of pts with unknown nodal status (50), there were no DRs. Conclusions: The RS result is predictive of DR at 5 yrs as shown in historical datasets (Table). The use of ODX to guide adjuvant treatment recommendations in our contemporary, prospective cohort resulted in a much lower 5-year DR rate and thus supports its use to guide adjuvant treatment decisions. [Table: see text]

New coumarins from Pterocaulon polystachyum

Aerial parts of Pterocaulon polystachyum from Chaco province, Argentina, afforded the known coumarins ayapin, isoscopoletin, prenyletin, prenyletin methyl ether, virgatenol, obtusinin, 5-methoxy-6,7-methylenedioxycoumarin, 5-(3,3-dimethylallyloxy)-6,7-methylenedioxycoumarin, 5-(2',3'-dihydroxy-3-methylbutanoxy)-6,7-methylenedioxycoumarin, haplopinol methyl ether, 6-(1,1-dimethyl-2-propenyl)-7-hydroxycoumarin and demethylnieshoutin; the last two are new as natural products while the five new coumarins from the collection were isovirgatenol, 3'-deoxyobtusinin, 6-methoxy-7-(2'-hydroxyethoxy)-coumarin, 5-(2'-hydroxyethoxy)-6,7-methylenedioxycoumarin and a substance tentatively identified as 5-hydroxy-6,7-methylenedioxy-8-(3,3-dimethylallyl)-coumarin.

Altered expression of natriuretic peptide receptors in proANP gene disrupted mice

BACKGROUND

The atrial natriuretic peptide (ANP) family is a complex system consisting of at least three polypeptides and at least three types of receptor. Each peptide interacts with different types of receptor at varying degrees of affinity. To determine if natriuretic peptide levels influence natriuretic peptide receptor expression and regulation, we examined the expression of guanylyl cyclase linked GC-A, GC-B and C-receptor in the lungs of mice with a mutation that inactivates the ANP gene (Nppa).

METHODS

The mRNA level of GC-A, GC-B and C-receptor in the lung were studied by ribonuclease protection assays (RPA).

RESULTS

Results of RPA showed that although the mRNA level of GC-A and GC-B of heterozygous ANP+/- was not different from wild type ANP+/+ mice, they were significantly higher in the homozygous mutant ANP-/- mice. In addition, C-receptor mRNA level in ANP+/- and ANP-/- was significantly lower than ANP+/+ mice. The C-receptor results were confirmed by receptor binding assays and affinity cross-linking studies.

CONCLUSIONS

Taken together these data suggest that permanent removal of ANP from the natriuretic peptide system results in an up-regulation of GC-A and GC-B, and a corresponding down-regulation of C-receptor in the lung of proANP gene disrupted mice. We postulated that changes in the natriuretic peptide receptor population may result in chronic hypertension and cardiac hypertrophy in the ANP-/- mice.

Tissue-specific modulation of rat glucagon receptor mRNA by thyroid status

The influence of thyroid status on glucagon receptor mRNA levels was investigated in rats using a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Glucagon receptor mRNA was detected in liver, brown and white adipose tissues (BAT and WAT) and brain. In BAT and WAT, pharmacologically-induced moderate hypothyroidism resulted in a marked reduction in the relative abundance of glucagon receptor mRNA. Short-term treatment of hypothyroid rats with exogenous 3,3',5'-triiodo-L-thyronine (T3), resulting in a marked hyperthyroidism, reversed the phenomenon in BAT while the reversal was only partial in WAT. In the liver, there was no significant effect of mild hypothyroidism while there was a positive effect of hyperthyroidism. In brain, the relative tissue abundance of glucagon receptor mRNA was not affected by the large changes in plasma T3. The present results therefore indicate that thyroid status may modulate the relative abundance of glucagon receptor mRNA in a tissue-specific manner.

Treatment of congenital Chagas' disease diagnosed and followed up by the polymerase chain reaction

In 1991 and 1992, a prenatal screening of Trypanosoma cruzi infection was carried out using ELISA and indirect immunofluorescence techniques. A total of 840 blood samples from pregnant women, obtained at the Maternity Ward of the Hospital de Clínicas, National University of Asunción (Asunción, Paraguay), and 1,022 samples from the Regional Hospital of the San Pedro Department of Paraguay were examined. It was observed that 7.7% and 10.5%, respectively, of the pregnant women were serologically positive for infection with T. cruzi. When blood samples obtained from newborns on the day of birth or, at the most, on the first few days afterwards were examined by direct microscopic observation, an incidence of congenital transmission of 3% was found. These results are consistent with those of neighboring countries. When a serologic follow-up was conducted on the newborns until six months of age, the incidence of congenital transmission reached 10%. The same incidence rate was obtained when the samples collected during the first days after birth were examined by the polymerase chain reaction (PCR). Fifty-eight infants born to seropositive mothers were followed-up, two of which were positive by direct microscopic observation at birth, and four who were PCR-positive, but microscopy-negative at birth. None of the infants were positive for IgM at birth. The infected babies were treated with benznidazole and were followed-up by serology and PCR for four years. We conclude that the PCR has a clear advantage over conventional techniques for the early detection of congenital transmission of T. cruzi infection, and for monitoring infants undergoing chemotherapy.

Alteration of the syncytium-forming property of XC cells by productive Moloney leukemia virus infection

The effect of productive murine leukemia virus (MuLV) infection of the syncytium-forming property of XC cells was studied MuLV-Moloney-infected XC cells, designated XC(M), initially went through a period of spontaneous syncytium formation. The syncytia then disappeared, and XC(M) cells continued to propagate and produce both infectious MuLV and MuLV group-specific antigens. However, XC(M) cells became refractory to syncytium formation that was induced by Kirsten, Friend, Rauscher, and Moloney strains of murine oncornaviruses. These data suggest that XC(M) cells lost their syncytium-forming ability as a result of productive MuLV infection.