Spleen phenotype in autosomal dominant polycystic kidney disease.

AIM: To evaluate splenic phenotype in autosomal dominant polycystic kidney disease (ADPKD) including presence of cysts and splenomegaly to determine if these are ADPKD related or represent unrelated incidental findings. MATERIALS AND METHODS: The axial/coronal T2-weighted images of ADPKD patients (n=215) and age/gender-matched controls (n=215) were evaluated for the presence of T2-bright splenic lesions by three blinded observers. Spleen volume (SV) was evaluated in the context of clinical and imaging features as well as results of gene testing for PKD1 and PKD2 mutations. RESULTS: T2-bright splenic lesions were found in 16 of 215 (7%) ADPKD patients compared to 11 of 215 (5%) control patients (p=0.32) and their prevalence was similar in patients with either PKD1 or PKD2 mutations. Median SV was significantly higher in ADPKD patients than controls (236 [182; 313 ml] versus 176 [129; 264 ml], p<0.0001). In multivariable analysis, height-adjusted SV (htSV) was not associated with the presence of liver cysts, haemorrhagic cysts, or infections; however, htSV was directly associated with height-adjusted total kidney volume (htTKV), a biomarker for ADPKD disease severity. CONCLUSIONS: The prevalence of T2-bright splenic lesions is similar in ADPKD patients and non-ADPKD controls, suggesting no relation to the diagnosis of ADPKD; however, splenic enlargement in ADPKD compared to controls could not be explained by liver cystic involvement, by infection/inflammatory conditions, or by haemorrhagic renal cysts. This combined with direct correlation of htSV with htTKV, a biomarker of ADPKD severity, suggests splenomegaly may be related to the pathogenesis of ADPKD.

Implications of ICD-10 for Sarcopenia Clinical Practice and Clinical Trials: Report by the International Conference on Frailty and Sarcopenia Research Task Force.

Establishment of an ICD-10-CM code for sarcopenia in 2016 was an important step towards reaching international consensus on the need for a nosological framework of age-related skeletal muscle decline. The International Conference on Frailty and Sarcopenia Research Task Force met in April 2017 to discuss the meaning, significance, and barriers to the implementation of the new code as well as strategies to accelerate development of new therapies. Analyses by the Sarcopenia Definitions and Outcomes Consortium are underway to develop quantitative definitions of sarcopenia. A consensus conference is planned to evaluate this analysis. The Task Force also discussed lessons learned from sarcopenia trials that could be applied to future trials, as well as lessons from the osteoporosis field, a clinical condition with many constructs similar to sarcopenia and for which ad hoc treatments have been developed and approved by regulatory agencies.

Autosomal dominant polycystic kidney disease caused by somatic and germline mosaicism.

Autosomal dominant polycystic kidney disease (ADPKD) is a heterogeneous genetic disorder caused by loss of function mutations of PKD1 or PKD2 genes. Although PKD1 is highly polymorphic and the new mutation rate is relatively high, the role of mosaicism is incompletely defined. Herein, we describe the molecular analysis of ADPKD in a 19-year-old female proband and her father. The proband had a PKD1 truncation mutation c.10745dupC (p.Val3584ArgfsX43), which was absent in paternal peripheral blood lymphocytes (PBL). However, very low quantities of this mutation were detected in the father's sperm DNA, but not in DNA from his buccal cells or urine sediment. Next generation sequencing (NGS) analysis determined the level of this mutation in the father's PBL, buccal cells and sperm to be ∼3%, 4.5% and 10%, respectively, consistent with somatic and germline mosaicism. The PKD1 mutation in ∼10% of her father's sperm indicates that it probably occurred early in embryogenesis. In ADPKD cases where a de novo mutation is suspected because of negative PKD gene testing of PBL, additional evaluation with more sensitive methods (e.g. NGS) of the proband PBL and paternal sperm can enhance detection of mosaicism and facilitate genetic counseling.

Effects of an 11ß-hydroxysteroid dehydrogenase type 1 inhibitor, MK-0916, in patients with type 2 diabetes mellitus and metabolic syndrome.

AIM: We examined the effects of the 11ß-hydroxysteroid dehydrogenase type 1 (HSD1) inhibitor, MK-0916, on the multiple components of the metabolic syndrome (MetS) in patients with type 2 diabetes (T2DM) and MetS. METHODS: This was a 12-week, multicentre, randomized, double-blind, placebo-controlled study. Patients with T2DM (mean baseline A1C: 7.3%) and National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III)-defined MetS were randomized 1 : 1 : 1 : 1 to 0.5, 2 or 6 mg/day MK-0916 or placebo. The primary efficacy endpoint was a change from baseline at week 12 in fasting plasma glucose (FPG). Secondary endpoints included glycosylated haemoglobin A(1c) (A1C), 2-h postprandial glucose (2-h PPG), body weight, waist circumference, blood pressure and lipid profile. RESULTS: Treatment with MK-0916 had no significant effect relative to placebo on FPG at week 12. Compared to placebo, 6 mg MK-0916 produced a modest, significant (p = 0.049) reduction in A1C of 0.3% at week 12, but no significant difference was observed in 2-h PPG. Six milligram MK-0916 increased LDL-C relative to placebo by 10.4% (p = 0.041). Treatment with MK-0916 led to modest dose-dependent decreases in blood pressure and body weight. Overall, MK-0916 was generally well tolerated. MK-0916 produced mechanism-based activation of the hypothalamic-pituitary-adrenal axis, resulting in mean increases in adrenal androgen levels that remained within the normal range at all doses tested. CONCLUSIONS: Inhibition of HSD1 with MK-0916 was generally well tolerated in patients with T2DM and MetS. Although no significant improvement in FPG was observed with MK-0916 compared to placebo, modest improvements in A1C, body weight and blood pressure were observed.

Aberrant PKD2 splicing due to a presumed novel missense mutation in autosomal-dominant polycystic kidney disease.

Autosomal-dominant polycystic kidney disease (ADPKD) is a heterogeneous genetic disorder characterized by abnormal proliferation of renal tubular epithelium, leading to massive kidney enlargement and progressive chronic kidney disease. ADPKD is caused by mutations in PKD1 and PKD2 genes. Herein, we describe and characterize a novel missense mutation in the PKD2 gene (c.1320G>T) in a 41-year-old White man with kidney cysts and a family history of ADPKD. This mutation abolishes a conserved acceptor splice site of intron 5, resulting in a premature termination following the addition of three aberrant amino acids (PKD2 p.L441C fsX4). We demonstrate that the aberrantly spliced transcript is found in substantial amounts in the patient's peripheral blood leukocytes (PBL), and show that this alternative splicing of exon 6 occurs, to a lesser magnitude, in other patients with ADPKD and in normal control individuals. The biological and clinical significance of this splice variant in ADPKD is currently unknown.

Anomalous extraocular muscles with strabismus.

SUMMARY: An 8-month-old boy with Gorlin syndrome presented with a large right-face turn and constant exotropia of the left eye. Eight-millimeter recession of the left lateral rectus muscle was performed at 23 months of age without complete postoperative improvement. Orbital imaging revealed bilateral anomalous extraocular muscles inferolateral to the optic nerves. Surgical resection of the tissue confirmed the accessory musculature with postoperative correction of the strabismus. To our knowledge, this appears to be the first reported case in the radiologic literature.

Associations of maternal prenatal dietary intake of n-3 and n-6 fatty acids with maternal and umbilical cord blood levels.

Maternal n-3 and n-6 polyunsaturated fatty acid (PUFA) status may influence birth outcomes and child health. We assessed second trimester maternal diet with food frequency questionnaires (FFQs) (n=1666), mid-pregnancy maternal erythrocyte PUFA concentrations (n=1550), and umbilical cord plasma PUFA concentrations (n=449). Mean (SD) maternal intake of total n-3 PUFA was 1.17 g/d (0.43), docosahexaenoic and eicosapentaenoic acids (DHA+EPA) 0.16 g/d (0.17), and total n-6 PUFA 12.25 g/d (3.25). Mean maternal erythrocyte and cord plasma PUFA concentrations were 7.0% and 5.2% (total n-3), 5.0% and 4.6% (DHA+EPA), and 27.9% and 31.4% (total n-6). Mid-pregnancy diet-blood and blood-blood correlations were strongest for DHA+EPA (r=0.38 for diet with maternal blood, r=0.34 for diet with cord blood, r=0.36 for maternal blood with cord blood), and less strong for n-6 PUFA. The FFQ is a reliable measure of elongated PUFA intake, although inter-individual variation is present.

Effect of bolus and divided feeding on urine ions and supersaturation in genetic hypercalciuric stone-forming rats.

Because urine ion excretion varies throughout the day, clinicians monitor 24 h urine samples to measure ion excretion and supersaturation in kidney stone patients. However, these results are averages and may not reflect maximal supersaturation which drives stone formation. We measured ion excretion and saturation in genetic hypercalciuric stone-forming rats on both a normal or low calcium diet over 0-3, 3-6 and 6-24 h using two feeding protocols, where the daily food allotment was fed either as a bolus or divided into three portions. With a normal calcium diet, urine calcium, oxalate, volume, and calcium oxalate supersaturation were significantly greater on the bolus compared to the divided feeds in the prandial and postprandial periods. Bolus eaters also excreted more calcium and oxalate and had increased volume over 24 h. Maximal calcium oxalate supersaturation was greater during the initial time periods than during the entire 24 h, regardless of the feeding schedule. With the low calcium diet, the effect of bolus feeding was reduced. Thus, urine ion excretion and supersaturation vary with the type of feeding. If these results are confirmed in man, it suggests that eating as a bolus may result in greater prandial and postprandial calcium oxalate supersaturation. This may increase growth on Randall's plaques and promote stone disease.

Urine calcium excretion predicts bone loss in idiopathic hypercalciuria.

Although idiopathic hypercalciuria (IH) is associated with reduced bone mineral density (BMD), no studies to date have identified predictors of BMD change over an extended period of observation. We have studied change in femoral neck and spine BMD z-scores in men and women with IH and stone disease (IHSF) and their first-degree relatives in order to determine the predictive value of commonly made clinical measurements. Urine calcium excretion was inversely correlated with change in femoral neck z-score over 3 years, and marginally correlated with fall in spine z-score. Markers of bone turnover, serum calcitriol, and urine measurements of acid-base balance such as ammonium and sulfate had no predictive value, nor did calcium intake assessed using a well-established questionnaire. It would appear that IHSF with the highest 24-h urine calcium excretion rates are at highest risk for loss of femoral neck bone mineral over a 3-year period.

Infantile infection and diabetes insipidus in children with optic nerve hypoplasia.

BACKGROUND: Bilateral optic nerve hypoplasia (BONH) is often associated with other central nervous system midline abnormalities (septo-optic dysplasia). Hormonal dysfunction, caused by anterior (cortisol) and posterior (ADH) pituitary involvement, can be sudden, severe, and life threatening. METHODS: Case series. Three cases of septo-optic dysplasia (SOD) presenting as infantile infection with associated diabetes insipidus are reported. The diagnosis of SOD was suspected only after ophthalmological evaluation; further evaluation led to the diagnosis of panhypopituitarism. CONCLUSIONS: A high index of suspicion is required to diagnose SOD in children when the disorder presents with infantile infection and hypernatraemia. Early warning signs of neonatal jaundice and hypoglycaemia should prompt ophthalmological evaluation.

Simulation of the impact of atropisomer interconversion on plasma exposure of atropisomers of an endothelin receptor antagonist.

BMS-207940, a potent endothelin receptor antagonist, exists as rapidly interconverting atropisomers. The plasma interconversion t(1/2) is approximately 2.5 hours at 400 microg/mL under room temperature and decreases to < 0.1 hours at 20 microg/mL, making it extremely difficult to conduct pharmacokinetic studies of individual atropisomers. The pharmacokinetics of the 50/50 racemate of BMS-207940 in humans were reasonably described by a one-compartmental model with an apparent terminal elimination t(1/2) of 15 hours. Given the above rates, simulations were conducted based on a one-compartmental model to explore the possible range of individual rates of atropisomer elimination and potential difference in plasma exposure to the two atropisomers. Simulations demonstrated that the elimination rates of the individual atropisomers are bounded between 0 and 0.046 h(-1) and between 0.046 and 0.092 h(-1), respectively. The estimation of the upper bounds for atropisomer elimination rate constants is robust and relatively insensitive to the rate of atropisomer interconversion compared to the rate of racemate elimination. Simulations of the administration of a single atropisomer or the 50/50 racemate, based on all the possible scenarios of individual atropisomer elimination, showed little difference in plasma exposure to the two atropisomers. Potential differences in plasma exposure to the two atropisomers depend, to a larger extent, on the ratio of the rate of atropisomer interconversion versus racemate elimination and, to a lesser extent, on the conformation of atropisomers administered. When atropisomer interconversion is 10-fold or more rapid than racemate elimination, the largest possible difference in plasma exposure between the two atropisomers is below 20%, regardless of the route and conformation of the atropisomer(s) administered.

Cost analysis of fentanyl and remifentanil in coronary artery bypass graft surgery without cardiopulmonary bypass.

BACKGROUND: Opiates such as remifentanil have the potential to reduce time to extubation (TTE), shorten length of stay (LOS) and lower hospital costs, because of a short duration of action. However, the cost of remifentanil is approximately ten times higher than longer-acting opiates like fentanyl. OBJECTIVES: The objective of this analysis was to compare TTE, LOS and total hospital costs between patients who received remifentanil and fentanyl during off-pump bypass surgery. METHODS: The study was prospective and observational in design. Consecutive patients who underwent off-pump cardiac bypass surgery and received either remifentanil or fentanyl from September 1998 to August 1999 were screened for study entry. Patient bills and charges were converted to costs using hospital cost-to-charge ratios. The percent of patients' extubated in the operating room (OR), LOS and hospital costs were compared between the groups. RESULTS: The baseline demographics (age: 66 +/- 12 years mean +/- SD; female 36%) and intraoperative variables were similar between the remifentanil (n=39) and fentanyl (n=20) groups. Patients given remifentanil during surgery were significantly more likely to be extubated in the OR than patients given fentanyl (15 vs. 64%; P < 0.001). Mean LOS was similar in both groups (7.3 +/- 3.1 vs. 8.3 +/- 2.7 days; P=0.27). Patients who received remifentanil incurred lower pulmonary function testing ($0 +/- 0 vs. $34 +/- 103; P=0.045), recovery room ($31 +/- 40 vs. $65 +/- 33; P=0.002) and lower ward costs ($3973 +/- 1719 vs. $4808 +/- 1794; P=0.09) than patients who received fentanyl. Anesthesia costs were higher among patients who received remifentanil ($476 +/- 102 vs. $416 +/- 130; P=0.06). Medical and surgical supplies, OR, intensive care unit, laboratory, respiratory therapy, pharmacy, radiology and transfusion costs were similar between the two groups. The total cost was $15 272 +/- 5556 and $15 616 +/- 4169 in the remifentanil and fentanyl groups, respectively (P=0.81). CONCLUSION: Remifentanil, when used in off-pump bypass surgery, is associated with an increased likelihood of extubation in the OR. However, LOS and total hospital costs remain unchanged.

Age-based refinement of referral criteria for photoscreening.

OBJECTIVE: To evaluate examination results from preschool children referred from photoscreening, and to adjust referral criteria for suspected astigmatism. DESIGN: Cross-sectional study and noncomparative case series. PARTICIPANTS: Thirty-one thousand fifty-three preschool children. METHODS: Analysis of (1) referral rate and unreadable photograph rate for all children screened, (2) examination results and treatment plan for all children referred for suspected astigmatism, and (3) examination results and treatment for all referred children aged less than 1 year. MAIN OUTCOME MEASURES: Referral rate, unreadable photograph rate, predictive value positive, treatment plan. RESULTS: The referral rate dropped from 7.8% for children 6 to 11 months to 5.3% for all other ages. The unreadable photograph rate declined exponentially from 12.1% for children aged 6 to 11 months to 1.1% for children aged 4 years. The predictive value positive of a photoscreen referral for all children in the 6- to 11-month age group was 30%, and only 12 of the 94 referred children were treated. The predictive value positive for children less than 1 year of age referred with suspected astigmatism was even lower (25%), and only one child in this age group was treated. The predictive value positive increased with age, and a higher percentage of older children were treated. For children at least 3 years old referred for suspected astigmatism, the predictive value positive was 67% when the examination was performed by a pediatric ophthalmologist. Strabismus, anisometropia, and high hypermetropia were diagnosed in such patients age 2 and older but never in younger children. CONCLUSIONS: Children less than 1 year of age have a much lower pass rate from photoscreening than do older children because of a higher referral rate and higher unreadable rate in this age group. When these children are examined, significant pathosis is usually absent, and intervention is rarely initiated. Most children age 2 and older who are referred for suspected astigmatism have a high likelihood of significant pathosis. It is probably unnecessary to examine children less than age 2 when their photoscreening suggests only astigmatism; conversely, referrals should still be provided for these children when their screening suggests other potentially amblyogenic factors.

Skew deviation and inferior oblique palsy.

PURPOSE: To describe ocular motility and neuro-ophthalmologic findings in six patients with an ocular tilt reaction (OTR) that mimicked an inferior oblique palsy (IOP). DESIGN: Observational Case Series. METHODS: Series of six patients presenting to tertiary care pediatric or neuro-ophthalmologist. RESULTS: Five patients had ocular motility and three-step test results suggesting an IOP; one patient had a suspected bilateral IOP. All six patients had excyclotorsion of the hypotropic eye, and four had incyclotorsion of the hypertropic eye. This is contrary to that expected with an IOP (incyclotorsion of the hypotropic eye). In addition, all six patients had other neurologic findings in the history or examination that were associated with neurologic insult rather than an isolated IOP. Two patients had surgery consisting of a superior rectus recession; this was successful in eliminating diplopia in both patients and in eliminating the vertical deviation and head posturing in one patient. CONCLUSION: While many vertical deviations that appear to be due to an inferior oblique palsy based on the results of the three-step test may be caused by inferior oblique weakness, skew deviation should also be considered in any patient with a history of head trauma, or other neurologic findings. The cyclotorsion observed in IOP is opposite that seen with OTR, and differentiates the two entities clinically. We postulate that these deviations are caused by damage to the otolithic projections that correspond to those from the ipsilateral posterior semicircular canal (on the side of the hypotropic eye).

Flow-induced calcium oscillations in rat osteoblasts are age, loading frequency, and shear stress dependent.

Bone adaptation to mechanical loading is dependent on age and the frequency and magnitude of loading. It is believed that load-induced fluid flow in the porous spaces of bone is an important signal that influences bone cell metabolism and bone adaptation. We used fluid flow-induced shear stress as a mechanical stimulus to study intracellular calcium (Ca) signaling in rat osteoblastic cells (ROB) isolated from young, mature, and old animals. Fluid flow produced higher magnitude and more abundant [Ca(2+)](i) oscillations than spontaneous oscillations, suggesting that flow-induced Ca signaling encodes a different cellular message than spontaneous oscillations. ROB from old rats showed less basal [Ca(2+)](i) activity and were less responsive to fluid flow. Cells were more responsive to 0.2 Hz than to 1 or 2 Hz and to 2 Pa than to 1 Pa. These data suggest that the frequency and magnitude of mechanical loading may be encoded by the percentage of cells displaying [Ca(2+)](i) oscillations but that the ability to transduce this information may be altered with age.

Primary oblique muscle overaction: the brain throws a wild pitch.

BACKGROUND: Sensorimotor and orbital anatomical mechanisms have been invoked to explain primary oblique muscle overaction. METHODS: Review of primitive visuo-vestibular reflexes and neuroanatomical pathways corresponding to vestibulo-ocular reflexes, and correlation with known clinical abnormalities in patients with primary oblique muscle overaction. RESULTS: Bilateral superior oblique muscle overaction, which corresponds to a backward pitch in lateral-eyed animals, can occur when structural lesions involving the brainstem or cerebellum increase central otolithic input to the extraocular muscle subnuclei that modulate downward extraocular muscle tonus. Bilateral inferior oblique overaction, which corresponds to a forward pitch in lateral-eyed animals, may result from visual disinhibition of central vestibular pathways to the extraocular muscle subnuclei that modulate upward extraocular muscle tonus. CONCLUSIONS: Primary oblique muscle overaction recapitulates the torsional eye movements that occur in lateral-eyed animals during body movements or directional luminance shifts in the pitch plane. These primitive ocular motor reflexes become manifest in humans when early-onset strabismus or structural lesions within the posterior fossa alter central vestibular tone in the pitch plane.