Diagnostic ultrasound of tendon injuries in the setting of distal radius fractures.

OBJECTIVE: Describe tendon injuries and their structural causes seen on ultrasound in wrists with distal radius fractures and estimate the accuracy of ultrasound and its impact on clinical management. MATERIALS AND METHODS: Ultrasounds of 226 wrists (221 patients) with distal radius fractures were retrospectively reviewed. Ultrasound findings of tendon injuries and their structural causes were correlated with surgery and clinical outcome. Accuracy and inter- and intra-observer reproducibilities were calculated. RESULTS: Twenty-five wrists were treated non-operatively while 201 underwent surgery. Ultrasound demonstrated hardware contact with flexor pollicis longus (FPL) in 76 wrists, extensor pollicis longus (EPL) in 21, and other tendons in 94. Ultrasound identified tendon ruptures in 23 wrists (13 EPL/8 FPL/2 extensor indicis proprius (EIP)), most of which were surgically confirmed. Among 12 wrists with confirmed EPL ruptures, distal radius fracture had been treated with volar plating in 6 and non-operatively in 6, and ultrasound showed osseous irregularity at the rupture site in 8. All FPL ruptures occurred in wrists with volar plating. Ultrasound findings were concordant with subsequent clinical management in most. In 2, ultrasound findings led to the decision to remove hardware despite lack of symptoms. Ultrasound had sensitivity/specificity/accuracy of 88/99/98% for identifying a specific tendon as ruptured and 88/87/88% for tendon abnormalities in general. Inter- and intra-observer reproducibilities were excellent (kappa = 0.85 ~ 1.0). CONCLUSION: Certain wrist tendons, particularly EPL and FPL, are vulnerable after distal radius fractures. Ultrasound is accurate and useful for detecting tendon injury and sources of tendon irritation and can guide clinical management.

Nomenclature of the radial nerve: distinguishing between the deep branch of the radial nerve and the posterior interosseous nerve.

To address an inconsistency in the nomenclature of the anatomy and compressive syndromes of the deep branch of the radial nerve, we advocate for a single compression syndrome that presents along a spectrum from pain to posterior interosseous nerve palsy.

Size-specific dose estimates for adult patients at CT of the torso.

PURPOSE: To determine relationships among patient size, scanner radiation output, and size-specific dose estimates (SSDEs) for adults who underwent computed tomography (CT) of the torso. MATERIALS AND METHODS: Informed consent was waived for this institutional review board-approved study of existing data from 545 adult patients (322 men, 223 women) who underwent clinically indicated CT of the torso between April 1, 2007, and May 13, 2007. Automatic exposure control was used to adjust scanner output for each patient according to the measured CT attenuation. The volume CT dose index (CTDI(vol)) was used with measurements of patient size (anterioposterior plus lateral dimensions) and the conversion factors from the American Association of Physicists in Medicine Report 204 to determine SSDE. Linear regression models were used to assess the dependence of CTDI(vol) and SSDE on patient size. RESULTS: Patient sizes ranged from 42 to 84 cm. In this range,CTDI(vol) was significantly correlated with size (slope = 0.34 mGy/cm; 95% confidence interval [CI]: 0.31, 0.37 mGy/cm; R(2) = 0.48; P < .001), but SSDE was independent of size (slope = 0.02 mGy/cm; 95% CI: -0.02, 0.07 mGy/cm; R(2) = 0.003; P = .3). These R(2) values indicated that patient size explained 48% of the observed variability in CTDI(vol) but less than 1% of the observed variability in SSDE. The regression of CTDI(vol) versus patient size demonstrated that, in the 42-84-cm range, CTDI(vol) varied from 12 to 26 mGy. However, use of the evaluated automatic exposure control system to adjust scanner output for patient size resulted in SSDE values that were independent of size. CONCLUSION: For the evaluated automatic exposure control system,CTDI(vol) (scanner output) increased linearly with patient size; however, patient dose (as indicated by SSDE) was independent of size.

Levels of phosphodiesterase 4A and 4B are altered by chronic treatment with psychotropic medications in rat frontal cortex.

Our laboratory has recently demonstrated altered expression of phosphodiesterase (PDE) 4A and 4B in subjects with autism, bipolar disorder, and schizophrenia, suggesting disrupted cAMP signaling in these diagnostic groups. In the current study, we measured expression of PDEs in rat frontal cortex (FC) following chronic treatment with clozapine, fluoxetine, haloperidol, lithium, olanzapine, valproic acid (VPA), or sterile saline for 21 days. Western blotting experiments showed decreased expression of PDE4A subtypes in FC following treatment with clozapine, haloperidol, lithium, and VPA. PDE4B subtypes were similarly reduced in FC following treatment with clozapine, fluoxetine, and lithium. We also measured levels of nine PDE subtypes via qRT-PCR in FC and found significant upregulation of PDE1A and PDE8B following treatment with olanzapine, while treatment with lithium reduced expression of mRNA for PDE8B. Our results demonstrate altered expression of PDE4A and PDE4B in response to a variety of psychotropic medications suggesting potentially new therapeutic avenues for treatment of neuropsychiatric diseases.

Dual-source computed tomographic temporal resolution provides higher image quality than 64-detector temporal resolution at low heart rates.

OBJECTIVE: To compare coronary image quality at temporal resolutions associated with dual-source computed tomography (DSCT; 83 milliseconds) and 64-detector row scanning (165 milliseconds). METHODS: In 30 patients with a heart rate of less than 70 beats per minute, DSCT coronary angiograms were reconstructed at 83- and 165-millisecond temporal resolutions over different cardiac phases. A blinded observer graded coronary quality. RESULTS: The typical DSCT temporal resolution (83 milliseconds) showed a significantly greater quality at end-systole for all coronary vessels and at end-diastole for the right coronary and left anterior descending coronary arteries. For all vessels, the end-diastole produced the highest quality for both temporal resolutions. CONCLUSIONS: Imaging at 83 milliseconds creates superior quality at end-systole for all coronary vessels and at end-diastole for the right coronary and left anterior descending coronary arteries. At low heart rates, end-diastole produces the highest quality at both temporal resolutions.

Strategies for reducing radiation dose in CT.

In recent years, the media has focused on the potential danger of radiation exposure from CT, even though the potential benefit of a medically indicated CT far outweighs the potential risks. This attention has reminded the radiology community that doses must be as low as reasonably achievable (ALARA) while maintaining diagnostic image quality. To satisfy the ALARA principle, the dose reduction strategies described in this article must be well understood and properly used. The use of CT must also be justified for the specific diagnostic task.

Expression of phosphodiesterase 4 is altered in the brains of subjects with autism.

The cyclic adenosine monophosphate-specific phosphodiesterase-4 (PDE4) gene family is the target of several potential therapeutic inhibitors and the PDE4B gene has been associated with schizophrenia and depression. Little, however, is known of any connection between this gene family and autism, with limited effective treatment being available for autism. We measured the expression of PDE4A and PDE4B by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting in Brodmann's area 40 (BA40, parietal cortex), BA9 (superior frontal cortex), and cerebellum from subjects with autism and matched controls. We observed a lower expression of PDE4A5, PDE4B1, PDE4B3, PDE4B4, and PDE4B2 in the cerebella of subjects with autism when compared with matched controls. In BA9, we observed the opposite: a higher expression of PDE4AX, PDE4A1, and PDE4B2 in subjects with autism. No changes were observed in BA40. Our results demonstrate altered expressions of the PDE4A and PDE4B proteins in the brains of subjects with autism and might provide new therapeutic avenues for the treatment of this debilitating disorder.

Radiation exposure and pregnancy: when should we be concerned?

The potential biological effects of in utero radiation exposure of a developing fetus include prenatal death, intrauterine growth restriction, small head size, mental retardation, organ malformation, and childhood cancer. The risk of each effect depends on the gestational age at the time of exposure, fetal cellular repair mechanisms, and the absorbed radiation dose level. A comparison between the dose levels associated with each of these risks and the estimated fetal doses from typical radiologic examinations lends support to the conclusion that fetal risks are minimal and, therefore, that radiologic and nuclear medicine examinations that may provide significant diagnostic information should not be withheld from pregnant women. The latter position is advocated by the International Commission on Radiological Protection, National Council on Radiation Protection, American College of Radiology, and American College of Obstetrics and Gynecology. However, although the risks are small, it is important to ensure that radiation doses are kept as low as reasonably achievable.

Generation of strength in a drying film: How fracture toughness depends on dispersion properties.

The fracture toughness of colloidal films is measured by characterizing cracks which form during directional drying. Images from a confocal microscope are processed to measure the crack width as a function of distance from the crack tip. Applying theory for thin elastic films the fracture toughness is extracted. It is found that the fracture toughness scales with the particle size to the -0.8 power and that the critical energy release rate scales with the particle size to the -1.3 power. In addition, the fracture toughness is found to increase at lower evaporation rates, but the film thickness does not have a significant effect.

Breastfeeding and coffee consumption in children younger than 2 years in Boston, Massachusetts, USA.

BACKGROUND: Although introduction of inappropriate foods and liquids in early childhood and their association with breastfeeding is commonly reported in US children, coffee use in very young US children and its association with breastfeeding is not. OBJECTIVES: This study aimed to determine the proportion of 1- and 2-year-olds in an urban population consuming coffee, their rate of consumption, and predictors of consumption, including breastfeeding status. METHODS: We used data from a prospective cohort study on infant weight gain and diet, and body mass index at age 2. We used bivariate analyses to examine variables associated with coffee consumption at 1 and 2 years and multivariate logistic regression to control for variables of interest. RESULTS: This study included 315 mother-infant dyads. At 1 year, the rate of coffee consumption reported was 2.5%; at 2 years, it was 15.2% and average daily consumption was 1.09 oz (range, 0.01- 4.00 oz). The only characteristic associated with coffee consumption at 1 year was breastfeeding at 1 year (P = .0275), which did not remain significant after controlling for confounding variables. Variables significantly associated with coffee consumption at year 2 were lower maternal education (P = .0016), non-US maternal place of birth (P = .0015), maternal Hispanic ethnicity (P < .0001), infant female sex (P = .0495), and receiving any breast milk at 1 year of age (P = .0189). After multivariate logistic regression, maternal Hispanic ethnicity (P = .0139) and infant female sex (P = .0371) remained significant. CONCLUSION: Coffee consumption is not uncommon among toddlers in Boston, Massachusetts, USA. After controlling for possible confounding factors, maternal ethnicity and infant sex were significantly associated with this practice.

Treating diet-induced diabetes and obesity with human embryonic stem cell-derived pancreatic progenitor cells and antidiabetic drugs.

Human embryonic stem cell (hESC)-derived pancreatic progenitor cells effectively reverse hyperglycemia in rodent models of type 1 diabetes, but their capacity to treat type 2 diabetes has not been reported. An immunodeficient model of type 2 diabetes was generated by high-fat diet (HFD) feeding in SCID-beige mice. Exposure to HFDs did not impact the maturation of macroencapsulated pancreatic progenitor cells into glucose-responsive insulin-secreting cells following transplantation, and the cell therapy improved glucose tolerance in HFD-fed transplant recipients after 24 weeks. However, since diet-induced hyperglycemia and obesity were not fully ameliorated by transplantation alone, a second cohort of HFD-fed mice was treated with pancreatic progenitor cells combined with one of three antidiabetic drugs. All combination therapies rapidly improved body weight and co-treatment with either sitagliptin or metformin improved hyperglycemia after only 12 weeks. Therefore, a stem cell-based therapy may be effective for treating type 2 diabetes, particularly in combination with antidiabetic drugs.

Determining length of breastfeeding exclusivity: validity of maternal report 2 years after birth.

BACKGROUND: Infant feeding data are often collected retrospectively through maternal report. Validation studies show that maternal report of initiation and duration of any breastfeeding is accurate but that report of duration of exclusive breastfeeding may be less accurate. OBJECTIVE: This study aimed to compare infant feeding data collected longitudinally throughout the first 6 months of life with maternal report of duration of exclusive breastfeeding collected 2 years postpartum. METHODS: Infant feeding data were collected prospectively throughout the first 6 months of life from medical records and maternal report, including maternal 24-hour recall. At 2 years postpartum, we asked mothers of these same infants how long they exclusively breastfed their infants. Their responses were compared to the prospectively collected data. Simple and multiple linear regressions tested for any significant predictors of the difference between the prospectively collected data and maternal report at 2 years. RESULTS: Of the 292 mothers included in the final analysis, only 88 (30.1%) mothers reported a duration of exclusive breastfeeding at 2 years postpartum that matched the prospectively collected data. Sixty-four women reported exclusively breastfeeding for the recommended 6 months (21.9%), but according to the prospectively collected data, only 2 women (0.7%) breastfed exclusively through 6 months. The median difference between the prospectively collected data and maternal report at 2 years was 1 month (IQR, 0-4). CONCLUSION: In this sample of mothers, report of exclusive breastfeeding practices 2 years after birth was often inaccurate and mothers tended to overestimate duration.

Optimal image reconstruction phase at low and high heart rates in dual-source CT coronary angiography.

The purpose of this study was to determine the cardiac phase having the highest coronary sharpness for low and high heart rate patients scanned with dual source CT (DSCT) and to compare coronary image sharpness over different cardiac phases. DSCT coronary CT scans for 30 low heart rate (< or =70 beats per minute- bpm) and 30 high heart rate (>70 bpm) patients were reconstructed into different cardiac phases, starting at 30% and increasing at 5% increments until 70%. A blinded observer graded image sharpness per coronary segment, from which sharpness scores were produced for the right (RCA), left main (LM), left anterior descending (LAD), and circumflex (Cx) coronary arteries. For each coronary artery, the phase with maximal image sharpness was identified with repeated measures analysis of variance. Comparison of coronary sharpness between low and high heart rate patients was made using generalized estimating equations. For low heart rates the highest sharpness scores for all four vessels (RCA, LM, LAD, and Cx) were at the 65 or 70% phase, which are end-diastolic cardiac phases. For high heart rates the highest sharpness scores were between the 35 and 45% phases, which are end-systolic phases. Low heart rate patients had higher coronary sharpness at most cardiac phases; however, patients with high heart rates had higher coronary sharpness in the 45% phase for all four vessels (P < 0.0001). Using DSCT scanning, optimal image sharpness is obtained in end-diastole at low heart rates and in end-systole in high heart rates.

Chronic psychotropic drug treatment causes differential expression of connexin 43 and GFAP in frontal cortex of rats.

Astrocytic markers glial fibrillary acidic protein (GFAP) and connexin 43 (CX43) are known to have altered expression in brains of subjects with psychiatric disorders including autism and major depression. The current study investigated whether GFAP and CX43 expressions are affected by several commonly used psychotropic medications (clozapine, fluoxetine, haloperidol, lithium, olanzapine, and valproic acid). Using SDS-PAGE and western blotting technique, we observed that CX43 protein expression in prefrontal cortex was significantly increased following chronic treatment with fluoxetine and clozapine, while it was significantly decreased by haloperidol and lithium. GFAP protein expression was significantly decreased following chronic treatment with clozapine and valproic acid. These results suggest that astroglial markers GFAP and CX43 could be potential targets for therapeutic intervention.