Geriatric Pharmacotherapy Case Series: Thiazide-Induced Hypokalemia.

Introduction The patient was a 72-year-old man with a history of hypertension, hyperlipidemia, benign prostatic hyperplasia, and oropharyngeal cancer. His home medications include amlodipine, atorvastatin, hydrochlorothiazide, and tamsulosin. He lives alone and eats a soft, bland, nutrient-poor diet. During his annual primary care visit, he is found to have a serum potassium level of 3.3 mEq/L (reference range 3.5-5.0). Assessment The use of hydrochlorothiazide, a thiazide diuretic, as well as his low consumption of dietary potassium, have likely contributed to his mild, asymptomatic hypokalemia. Outcome The patient's serum potassium normalizes following replenishment with a 10 mEq microencapsulated potassium chloride (KCl) extended release (ER) tablet three times a day with meals for one week. A registered dietitian was consulted to provide recommendations for a well-balanced diet, consistent with his dietary texture needs. Conclusions Hypokalemia is a commonly encountered electrolyte disorder, occurring in about 3 to 4% of community-dwelling elders.1 Though asymptomatic hypokalemia is often an incidental finding, it is associated with an increased risk of major adverse cardiovascular events if left untreated and thus should be promptly corrected when discovered.².

Anton August Heinrich Lichtensteins (1794) Catalogus Rerum Naturalium Rarissimarum, pars secunda. Facsimile edition and annotated translation.

The new species of Lichtensteins catalog (1794: part 2) were discussed by Geiger (2003). Here a facsimile edition and full translation of the work is given. Additional insights into select Lichtenstein species are provided. Tentative identifications include Mya papyracea Lichtenstein, 1794 as a member of Thraciidae, Helix porphyrostoma Lichtenstein, 1796 from Ambon as a member of Planorbidae and Helix australasiae Lichtenstein, 1794 from Tahiti as a Partula sp. Trochus tahitiensis Lichtenstein, 1794 is here designated as a nomen oblitum with Trochus histrio Reeve, 1861 [1842 in error] as its nomen protectum. Oliva brasiliensis Chemnitz and Murex galea Chemnitz (now Coralliophila galea) were first made available by Lichtenstein (1794), not by Schumacher (1817) and Dillwyn (1823), respectively. Olivancillaria brasiliensis (Lichtenstein, 1794) is senior synonym of O. urceus (Rding, 1798).

Species delineation and systematics of a hemiclonal hybrid complex in Australian freshwaters (Gobiiformes: Gobioidei: Eleotridae: Hypseleotris).

The rivers of southeastern Australia host a species complex within the carp gudgeon genus Hypseleotris that includes parental species and hemiclonal hybrid lineages. These hemiclones can be difficult to distinguish from their parent taxa, making delineation of species unusually difficult. We approach this historical taxonomic problem by using single nucleotide polymorphism (SNP) genotyping to distinguish individuals of each species and hemiclones, enabling us to quantify the variation among evolutionary lineages and assign names to the species. Hypseleotris klunzingeri remains valid and does not have any hemiclones. We describe Hypseleotris bucephala and Hypseleotris gymnocephala from the Murray-Darling Basin and Hypseleotris acropinna from the Murray-Darling as well as eastern coastal streams north of the Mary River, part of the range attributed to H. galii. We further split H. galii to distinguish a species from the Mary River, Hypseleotris moolooboolaensis. We designate a neotype and redescribe H. galii due to uncertainty about the source and species identity of specimens used in the original description. We reconcile previous taxonomies, provide new common names for parental species, and advocate using the scientific names of both parents when referring to the hemiclone hybrids to avoid confusion with previous common names that did not distinguish parental taxa and hemiclones.

Analysis of IBNR Liabilities with Interevent Times Depending on Claim Counts.

We extend a recently proposed stochastic loss reserving model for liabilities from incurred but not reported (IBNR) micro-level claims. We propose viewing the number of claims from an event as a measure of catastrophic severity. This view covers catastrophes with arbitrarily many classes of magnitude. Our Markovian model allows the time between disasters to depend on the previous event's level of severity. Simultaneously, we let the discount rate vary in the same manner. First, we find the moments of IBNR liabilities in our model. Then, we permit a later time horizon for IBNR claims when considered jointly with incurred and reported claims.

Scissurella nesbittae, new species, from the Gries Ranch Formation, Lewis County, Washington State (Gastropoda: Vetigastropoda: Scissurellidae).

Recent and fossil global scissurellids were monographed by Geiger (2012) and additional species were recently described from Brazil (Pimenta Geiger 2015). Here, we describe an additional fossil species from shallow water strata of the late Eocene Gries Ranch Formation in Lewis County, Washington State, USA.

Tracking Joint Angles During Whole-Arm Movements Using Electromagnetic Sensors.

Electromagnetic (EM) motion tracking systems are suitable for many research and clinical applications, including in vivo measurements of whole-arm movements. Unfortunately, the methodology for in vivo measurements of whole-arm movements using EM sensors is not well described in the literature, making it difficult to perform new measurements and all but impossible to make meaningful comparisons between studies. The recommendations of the International Society of Biomechanics (ISB) have provided a great service, but by necessity they do not provide clear guidance or standardization on all required steps. The goal of this paper was to provide a comprehensive methodology for using EM sensors to measure whole-arm movements in vivo. We selected methodological details from past studies that were compatible with the ISB recommendations and suitable for measuring whole-arm movements using EM sensors, filling in gaps with recommendations from our own past experiments. The presented methodology includes recommendations for defining coordinate systems (CSs) and joint angles, placing sensors, performing sensor-to-body calibration, calculating rotation matrices from sensor data, and extracting unique joint angles from rotation matrices. We present this process, including all equations, for both the right and left upper limbs, models with nine or seven degrees-of-freedom (DOF), and two different calibration methods. Providing a detailed methodology for the entire process in one location promotes replicability of studies by allowing researchers to clearly define their experimental methods. It is hoped that this paper will simplify new investigations of whole-arm movement using EM sensors and facilitate comparison between studies.

Biosynthetic approach to combine the first steps of cardenolide formation in Saccharomyces cerevisiae.

A yeast expression plasmid was constructed containing a cardenolide biosynthetic module, referred to as CARD II, using the AssemblX toolkit, which enables the assembly of large DNA constructs. The genes cloned into the vector were (a) a Δ5 -3ß-hydroxysteroid dehydrogenase gene from Digitalis lanata, (b) a steroid Δ5 -isomerase gene from Comamonas testosteronii, (c) a mutated steroid-5ß-reductase gene from Arabidopsis thaliana, and (d) a steroid 21-hydroxylase gene from Mus musculus. A second plasmid bearing an ADR/ADX fusion gene from Bos taurus was also constructed. A Saccharomyces cerevisiae strain bearing these two plasmids was generated. This strain, termed "CARD II yeast", was capable of producing 5ß-pregnane-3ß,21-diol-20-one, a central intermediate in 5ß-cardenolide biosynthesis, starting from pregnenolone which was added to the culture medium. Using this approach, five consecutive steps in cardenolide biosynthesis were realized in baker's yeast.

Angle-resolved light scattering of single human chromosomes: experiments and simulations.

Angle-resolved light scattering measurements of human metaphase chromosomes were compared to the results of numerical light scattering simulations with geometrical models based on atomic force microscopy (AFM) measurements of the same chromosomes. The simulations were conducted using the discrete dipole approximation method (DDA), which solves Maxwell's equations for induced dipoles, positioned in a discrete lattice. A remarkable agreement between the light scattering simulations and measurements of all 6 studied chromosomes was found. Additionally, the influence of small changes in the orientation of a complex scatterer geometry on its angle-resolved scattering pattern is shown. A method is presented to approximate such variations in the scatterer's orientation by a linear shift of the angular scattering pattern. This method provides an initial guess on the scatterers orientation, reducing the amount of simulations needed considerably. It was validated on simulations of a cuboid and successfully applied in the evaluation of the chromosome measurements.

A method for characterizing essential tremor from the shoulder to the wrist.

BACKGROUND: Despite the pervasive and devastating effect of Essential Tremor (ET), the distribution of ET throughout the upper limb is unknown. We developed a method for characterizing the distribution of ET and performed a preliminary characterization in a small number of subjects with ET. METHODS: Using orientation sensors and inverse kinematics, we measured tremor in each of the seven major degrees of freedom (DOF) from the shoulder to the wrist while ten patients with mild ET assumed 16 different postures. We described the tremor in each DOF in terms of power spectral density measures and investigated how tremor varied between DOF, postures, gravitational torques, and repetitions. FINDINGS: Our method successfully resulted in tremor measures in each DOF, allowing one to compare tremor between DOF and determine the distribution of tremor throughout the upper limb, including how the distribution changes with posture. In our small number of subjects, we found that the amount of power in the frequency band associated with ET (4-12Hz) was lowest in the shoulder and greatest in the wrist. Similarly, the existence and amplitude of peaks in this band increased from proximal to distal. Although the amount of tremor differed significantly between postures, we did not find any clear patterns with changes in posture or gravitational torque. INTERPRETATION: This method can be used to characterize the distribution of tremor throughout the upper limb. Our preliminary characterization suggests that the amount of tremor increases in a proximal-distal manner.

Measurement of contact angles of microscopic droplets by focal length method.

We present a method to measure contact angles of microscopic droplets with a conventional microscope that possesses a precision focus adjustment stage. The droplets are modeled as spherical caps that act as lenses. Their focal length is determined by measuring the distance from the substrate surface to the level where a sharp image of the aperture stop is observed. The lens diameter is found by edge detection of a microscope image of the microdroplets. The spherical cap model relates the focal length and diameter of such lenses to the contact angle of the used liquid with known refractive index. The measurement procedure was applied to condensed water droplets on a silicon substrate covered by its native oxide layer. The results are found to be in good agreement with conventional, goniometric sessile drop measurements of the advancing contact angle.

Toward quantitative characterization of essential tremor for future tremor suppression.

Tremor is the most common movement deficit and manifests in a variety of disorders, including Essential Tremor, Parkinson's Disease, Dystonia, and Cerebellar Ataxia. Although medication and surgical interventions have significantly reduced patient suffering, they are only partially effective and can carry undesired side effects, leaving many patients without satisfactory treatment options. Wearable tremor-suppressing devices could provide an alternative to medication and surgery. Multiple research groups have developed orthotic prototypes to low-pass filter tremor, but these devices have not yet been optimized for in-vivo use. Optimizing non-invasive tremor suppression requires an understanding of where the tremor originates mechanically (which muscles) and how it propagates to the hand (where it matters most). Here we present on the beginnings of our multi-pronged work to determine the origin, propagation, and distribution of Essential Tremor, and we provide preliminary results.

Severnsia strombeulima n. gen. & sp. from Hawaii (Mollusca, Gastropoda: Caenogastropoda: Eulimidae).

The malacofauna of Hawaii is rather well-known, owing to Kay (1979) and Severns (2011). Both works stand out because they include a large number of the generally under-represented micromollusks (<5 mm). Here a striking new genus and species of a microsnail is reported from that region.

Expression, crystallization and structure elucidation of γ-terpinene synthase from Thymus vulgaris.

The biosynthesis of γ-terpinene, a precursor of the phenolic isomers thymol and carvacrol found in the essential oil from Thymus sp., is attributed to the activitiy of γ-terpinene synthase (TPS). Purified γ-terpinene synthase from T. vulgaris (TvTPS), the Thymus species that is the most widely spread and of the greatest economical importance, is able to catalyze the enzymatic conversion of geranyl diphosphate (GPP) to γ-terpinene. The crystal structure of recombinantly expressed and purified TvTPS is reported at 1.65 Šresolution, confirming the dimeric structure of the enzyme. The putative active site of TvTPS is deduced from its pronounced structural similarity to enzymes from other species of the Lamiaceae family involved in terpenoid biosynthesis: to (+)-bornyl diphosphate synthase and 1,8-cineole synthase from Salvia sp. and to (4S)-limonene synthase from Mentha spicata.

Purification of Δ(5)-3-ketosteroid isomerase from Digitalis lanata.

The isomerization of 5-pregnene-3,20-dione into 4-pregnene-3,20-dione was investigated to shed further light on cardenolide biosynthesis and to characterize the enzymes involved in cardenolide formation. It was shown that the Δ(5)-3-ketosteroid isomerase of Digitalis lanata, which catalyzes this isomerization, is an individual enzyme and not, as previously thought, associated with Δ(5)-3ß-hydroxysteroid dehydrogenase. The enzyme was purified by fractionated ammonium sulfate precipitation, hydrophobic interaction chromatography and gel filtration. The purification protocol resulted in a 68.1-fold enriched specific enzyme activity with a yield of 2.2%. After an additional chromatofocusing step the 3KSI activity appeared as a single protein band at 17kDa in SDS-PAGE. Plant 3KSI displayed similar properties to microbial 3-ketosteroid isomerases.

Posterolateral and posteromedial corner injuries of the knee.

Posterolateral (PLC) and posteromedial (PMC) corners of the knee represent complex anatomic regions because of intricate soft tissue and osseous relationships in small areas. Concise knowledge of these relationships is necessary before approaching their evaluation at imaging. Magnetic resonance imaging offers an accurate imaging diagnostic tool to establish normal anatomy and diagnose and characterize soft tissue and osseous injury. It is important to carefully evaluate the PLC and PMC structures on magnetic resonance imaging before planned surgical intervention to avoid potential complications resulting from occult injury.

Quantitative 3D ultrashort time-to-echo (UTE) MRI and micro-CT (µCT) evaluation of the temporomandibular joint (TMJ) condylar morphology.

OBJECTIVE: Temporomandibular dysfunction involves osteoarthritis of the TMJ, including degeneration and morphologic changes of the mandibular condyle. The purpose of this study was to determine the accuracy of novel 3D-UTE MRI versus micro-CT (µCT) for quantitative evaluation of mandibular condyle morphology. MATERIALS AND METHODS: Nine TMJ condyle specimens were harvested from cadavers (2 M, 3 F; age 85 ± 10 years, mean ± SD). 3D-UTE MRI (TR = 50 ms, TE = 0.05 ms, 104-µm isotropic-voxel) was performed using a 3-T MR scanner and µCT (18-µm isotropic-voxel) was also performed. MR datasets were spatially registered with a µCT dataset. Two observers segmented bony contours of the condyles. Fibrocartilage was segmented on the MR dataset. Using a custom program, bone and fibrocartilage surface coordinates, Gaussian curvature, volume of segmented regions, and fibrocartilage thickness were determined for quantitative evaluation of joint morphology. Agreement between techniques (MRI vs. µCT) and observers (MRI vs. MRI) for Gaussian curvature, mean curvature, and segmented volume of the bone were determined using intraclass correlation coefficient (ICC) analysis. RESULTS: Between MRI and µCT, the average deviation of surface coordinates was 0.19 ± 0.15 mm, slightly higher than the spatial resolution of MRI. Average deviation of the Gaussian curvature and volume of segmented regions, from MRI to µCT, was 5.7 ± 6.5% and 6.6 ± 6.2%, respectively. ICC coefficients (MRI vs. µCT) for Gaussian curvature, mean curvature, and segmented volumes were 0.892, 0.893, and 0.972, respectively. Between observers (MRI vs. MRI), the ICC coefficients were 0.998, 0.999, and 0.997, respectively. Fibrocartilage thickness was 0.55 ± 0.11 mm, as previously described in the literature for grossly normal TMJ samples. CONCLUSIONS: 3D-UTE MR quantitative evaluation of TMJ condyle morphology ex-vivo, including surface, curvature, and segmented volume, shows high correlation against µCT and between observers. In addition, UTE MRI allows quantitative evaluation of the fibrocartilaginous condylar component.

Detection of small (≤2 cm) HCC in cirrhotic patients: added value of diffusion MR-imaging.

OBJECTIVES: To evaluate the usefulness of the diffusion-weighted sequence in the detection of small (≤2 cm) hepatocellular carcinoma (HCC) in patients with cirrhosis. METHODS: Seventy cirrhotic patients with 93 HCCs underwent MR-Imaging at 1.5 T. MR acquisitions comprised unenhanced T1- and T2-weighted images and post-contrast Gd-BOPTA-enhanced T1W GRE-3D images acquired after approximately 25, 60, 180 s (dynamic phases) and 90 min (hepatobiliary phase). DWI was performed by a SSEPI sequence (b values 0, 50, 400, 800 s/mm(2)). Quantitative analysis was performed to establish significant difference of ADC values of benign lesions compared with that of HCC. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of two different protocols with and without diffusion MRI sequence were also calculated and compared each other. RESULTS: A good inverse correlation was found between reference standard and ADC values (ρ = -0.688). The mean ADC value of HCC was significantly lower than the mean value of benign focal liver lesions (p < 0.0001). No significant difference was reported in term of sensitivity, specificity, PPV, NPV and diagnostic accuracy between the two datasets. A trend to a better sensitivity was found when DWI images were considered. CONCLUSIONS: The adjunction of DWI does not significantly improve the diagnostic accuracy in the detection of small HCC.

Posterolateral and posteromedial corner injuries of the knee.

Posterolateral (PLC) and posteromedial (PMC) corners of the knee represent complex anatomic regions because of intricate soft tissue and osseous relationships in small areas. Concise knowledge of these relationships is necessary before approaching their evaluation at imaging. Magnetic resonance imaging offers an accurate imaging diagnostic tool to establish normal anatomy and diagnose and characterize soft tissue and osseous injury. It is important to carefully evaluate the PLC and PMC structures on magnetic resonance imaging before planned surgical intervention to avoid potential complications resulting from occult injury.

Hepatocellular carcinoma in cirrhotic patients: prospective comparison of US, CT and MR imaging.

OBJECTIVES: To prospectively compare the diagnostic performance of ultrasound (US), multidetector computed tomography (MDCT) and contrast-enhanced magnetic resonance imaging (MRI) in cirrhotic patients who were candidates for liver transplantation. METHODS: One hundred and forty consecutive patients with 163 hepatocellular carcinoma (HCC) nodules underwent US, MRI and MDCT. Diagnosis of HCC was based on pathological findings or substantial growth at 12-month follow-up. Four different image datasets were evaluated: US, MDCT, MRI unenhanced and dynamic phases, MRI unenhanced dynamic and hepatobiliary phase. Diagnostic accuracy, sensitivity, specificity, PPV and NPV, with corresponding 95 % confidence intervals, were determined. Statistical analysis was performed for all lesions and for three lesion subgroups (<1 cm, 1-2 cm, >2 cm). RESULTS: Significantly higher diagnostic accuracy, sensitivity and NPV was achieved on dynamic + hepatobiliary phase MRI compared with US, MDCT and dynamic phase MRI alone. The specificity and PPV of US was significantly lower than that of MDCT, dynamic phase MRI and dynamic + hepatobiliary phase MRI. Similar results were obtained for all sub-group analyses, with particular benefit for the diagnosis of smaller lesions between 1 and 2 cm. CONCLUSIONS: Dynamic + hepatobiliary phase MRI improved detection and characterisation of HCC in cirrhotic patients. The greatest benefit is for diagnosing lesions between 1 and 2 cm.

64-Section multi-detector row CT in the preoperative diagnosis of peritoneal carcinomatosis: correlation with histopathological findings.

BACKGROUND: To prospectively investigate the diagnostic accuracy of a 64-section multi-detector row computed tomography (CT) for the detection of peritoneal metastases, with the use of surgery and histopathological findings as the reference standard. METHODS: The study cohort comprised 18 patients with peritoneal carcinomatosis who underwent multiphasic CT with a 64-section CT, 0-119 days before cytoreductive surgery. Transverse CT images along with isotropic reformatted coronal and sagittal images were prospectively and independently evaluated by one of the five staff radiologists in an unblinded fashion. RESULTS: The overall sensitivity, specificity, positive, and negative predictive values of CT for the detection of peritoneal metastases were, respectively, 75% (93 of 124 lesions; confidence interval [CI] 68-84), 92% (118 of 128; CI 85-96), 90% (93 of 103; CI 83-95), and 79% (118 of 149; CI 72-86). For lesions 0.5 cm in diameter or larger, CT yielded a mean sensitivity of 89% (77 of 87; CI 75-97), although sensitivity decreased to only 43% (16 of 37; CI 28-56) for lesions <0.5 cm in diameter. CONCLUSIONS: 64-Section CT with the addition of isotropic reformatted coronal and sagittal images is a very effective technique in the detection of peritoneal metastases of 0.5 cm in diameter or larger, although sensitivity decreases remarkably for lesions <0.5 cm in diameter.