Benign liver lesions: grey-scale and contrast-enhanced ultrasound appearances.

Ultrasound is often the first point of detection of liver lesions, with up to 75% of liver lesions detected at ultrasound having benign histology. In 2012, NICE issued recommendations that ultrasound contrast be used for the evaluation of incidentally discovered liver lesions. This has been demonstrated to provide a rapid and cost-effective evaluation for incidental liver lesions, in many cases precluding the need for further CT or MRI scans. The aim of this review is to demonstrate the ultrasound features of benign liver lesions, and to demonstrate their further characterisation with contrast ultrasound.

Acoustic radiation force impulse quantification: repeatability of measurements in selected liver segments and influence of age, body mass index and liver capsule-to-box distance.

OBJECTIVE: To assess the inter- and intra-observer variability of acoustic radiation force impulse (ARFI) quantification in liver segments with influence of age, body mass index (BMI) and liver capsule-to-box (CB) distance. METHODS: 10 healthy volunteers were examined twice, by three experienced operators, separated by a 1-week interval. 10 readings were obtained, from segments 3, 5/6 and 7/8. Age, BMI and the CB distance were noted. The Cronbach α statistic for analysis of reliability was performed for the inter- and intra-observer studies. Multivariate linear regression models determined significance of the other parameters. RESULTS: 1800 velocity measurements were recorded. Mean values±standard deviation: segment 3, 1.31±0.19 m s(-1); segment 5/6, 1.12±0.22 m s(-1); segment 7/8, 1.12±0.17 m s(-1). For both the inter- and intra-observer study, the Cronbach α statistic was ≥0.7 (reliable) when taken from segments 5/6 and 7/8 but <0.7 (unreliable) for segment 3. BMI and age showed significant (p<0.0001) but contrasting correlation (segment 5/6: BMI r=0.02, age r=-0.02; segment 7/8: BMI r=-0.01, age r=0.01) with ARFI velocities when analysed for the segments deemed reliable. A weak negative correlation between ARFI velocities and liver CB distance was demonstrated for both assessed segments (segment 5/6, r=-0.08; segment 7/8, r=-0.06; p<0.001). CONCLUSION: With trained operators, ARFI is a reliable and reproducible method of liver stiffness quantification in segments 5/6 and 7/8 but acquisition of measurements from segment 3 should be avoided. Values obtained deeper to the liver capsule allow more reliable liver stiffness quantification.

Structure and expression of the quinolinate phosphoribosyltransferase (QPT) gene family in Nicotiana.

Synthesis of wound-inducible pyridine alkaloids is characteristic of species in the genus Nicotiana. The enzyme quinolinate phosphoribosyltransferase (QPT) plays a key role in facilitating the availability of precursors for alkaloid synthesis, in addition to its ubiquitous role in enabling NAD(P)(H) synthesis. In a previous study, we reported that Nicotiana tabacum L. var. NC 95 possesses a QPT RFLP pattern similar to its model paternal progenitor species, Nicotiana tomentosiformis Goodsp. Here we show that although some varieties of N. tabacum (e.g. NC 95 and LAFC 53) possess QPT genomic contributions from only its paternal progenitor species, this is not the case for many other N. tabacum varieties (e.g. Xanthi, Samsun, Petite Havana SR1 and SC 58) where genomic QPT sequences from both diploid progenitor species have been retained. We also report that QPT is encoded by duplicate genes (designated QPT1 and QPT2) not only in N. tabacum, but also its model progenitor species Nicotiana sylvestris Speg. and Comes and N. tomentosiformis as well as in the diploid species Nicotiana glauca Graham. Previous studies have demonstrated that the N. tabacum QPT2 gene encodes a functional enzyme via complementation of a nadC(-)Escherichia coli mutant. Using a similar experimental approach here, we demonstrate that the N. tabacum QPT1 gene also encodes a functional QPT protein. We observe too that QPT2 is the predominate transcript present in both alkaloid and non-alkaloid synthesising tissues in N. tabacum and that promoter regions of both QPT1 and QPT2 are able to produce GUS activity in reproductive tissues. In N. tabacum and in several other Nicotiana species tested, QPT2 transcript levels increase following wounding or methyl jasmonate treatment whilst QPT1 transcript levels remain largely unaltered by these treatments. Together with conclusions from recently published studies involving functional interaction of MYC2-bHLH and specific ERF-type and transcription factors with QPT2-promoter sequences from N. tabacum, our results suggest that whilst both members of the QPT gene family can contribute to the transcript pool in both alkaloid producing and non-producing tissues, it is QPT2 that is regulated in association with inducible defensive pyridine alkaloid synthesis in species across the genus Nicotiana.

Bottomonium above deconfinement in lattice nonrelativistic QCD.

We study the temperature dependence of bottomonium for temperatures in the range 0.4T(c) < T < 2.1T(c), using nonrelativistic dynamics for the bottom quark and full relativistic lattice QCD simulations for Nf = 2 light flavors on a highly anisotropic lattice. We find that the Υ is insensitive to the temperature in this range, while the χb propagators show a crossover from the exponential decay characterizing the hadronic phase to a power-law behavior consistent with nearly free dynamics at T ≃ 2T(c).

Solitary rectal ulcer syndrome mimicking rectal neoplasm on MRI.

Solitary rectal ulcer syndrome (SRUS) is a rare condition that typically affects young adults and describes a spectrum of clinicopathological abnormalities. The diagnosis of SRUS is usually made on the basis of a combination of presenting symptoms and endoscopic and histological appearances. Characteristic radiological appearances have been described on transrectal and endoanal ultrasound, defecating proctography and barium enema. The radiological appearance of solitary rectal ulcer on MRI has not been previously described. MRI appearance of thickened ulcerated mucosa in the anterior rectal wall are non-specific and was indistinguishable from a malignant process. However, given that solitary rectal ulcer has a pre-disposition to occur in the anterior rectal wall, the presence on MRI of thickened rectal mucosa in this location could suggest solitary rectal ulcer in the correct clinical context.

Ultrasound imaging of liver metastases in the delayed parenchymal phase following administration of Sonazoid using a destructive mode technique (Agent Detection Imaging).

AIM: To determine whether delayed-phase liver imaging using a destructive imaging mode is able to provide similar information to phase-inversion imaging regarding detection and conspicuity of liver metastases. MATERIAL AND METHODS: Patients with a known primary malignancy with suspected liver metastases were recruited. Ultrasound was performed at baseline, and up to 5 min after the administration of Sonazoid, using phase-inversion imaging at both low and high mechanical indices (MI) and at 10-15 min using destructive imaging. One of four doses of Sonazoid was used: 0.008, 0.08, 0.12, and 0.36 microl/kg of body weight. Two observers documented lesion number and conspicuity subjectively, and divided the patients into group A (no lesions), group B (one to seven lesions), and group C(I-III) (more than eight lesions, subdivided with increasing lesion number) depending on the number of lesions and categories I-IV based on lesion conspicuity. These parameters were compared with contrast-enhanced computed tomography (CECT) as the reference standard. RESULTS: Sixteen patients were examined (six women, 10 men), mean age 67.3 years (range 48-83 years). Based on CECT imaging, the division was as follows: group A n=1, group B n=8, group C(I)n=1, group C(II)n=4, group C(III)n=2. The accuracy of baseline ultrasound versus CECT was 75% (in 12 of the 16 patients the group concurred) and the accuracy for contrast-enhanced ultrasound (CEUS) versus CECT was 93.8% (15/16). There was a significant improvement in lesion conspicuity for both low (p=0.0029) and high MI phase-inversion (p=0.0004) and destructive (p=0.0015) CEUS imaging in comparison with baseline ultrasound. Artefact was noted at higher doses of Sonazoid; and no side effects were recorded. CONCLUSION: Following a single, intravenous injection of Sonazoid, the properties of this microbubble allow for a and robust examination of the liver using two different techniques with comparable results.

Use of recombinant factor VIIa in massive post-partum haemorrhage.

BACKGROUND AND OBJECTIVE: Massive post-partum haemorrhage continues to be one of the world's leading causes of maternal morbidity and mortality. Any new treatment that potentially helps at risk parturients should be thoroughly investigated. Recombinant factor VIIa (rVIIa) is increasingly being used in the treatment of massive haemorrhage. We performed a case-matched analysis of its use since 2003 in the treatment of massive post-partum haemorrhage at our hospital. METHODS: Twenty-eight cases of massive post-partum haemorrhage were identified over a 3-yr period since 2003. In six of these cases, rVIIa was used as part of their management. Six case-matched controls were sought. The six women with the greatest requirement for packed red cell transfusion who also had a deranged prothrombin time were included. The groups were then compared for differences. The worst prothrombin time in each group was noted as was the best prothrombin time within 6 h, this was used as our measure of response to treatment. RESULTS: There was no statistical difference in age, gestation, parity, transfusion requirements, mode of delivery or the severity of the coagulopathy between the two groups. In both groups the prothrombin time improved with management. There was no significant difference in either the magnitude of the improvement in the value of the prothrombin time or the absolute value of the best prothrombin time (P = 0.09). Five out of the six women in the rFVIIa group had normal or low prothrombin times within 6 h yet only one woman who did not receive rFVIIa had a normal prothrombin time within 6 h though this was not significant (P = 0.08). CONCLUSIONS: This case-matched analysis supports the management of massive post-partum haemorrhage with appropriate resuscitation, surgical intervention and use of blood and blood products. This study does not support the routine use of rFVIIa in the management of massive obstetric haemorrhage. rFVIIa may have a role to play in this management but further studies and analyses will be required.

Advanced Merkel cell cancer and the elderly.

BACKGROUND: Merkel cell cancer (MCC) is an uncommon neuroendocrine skin cancer occurring predominantly in elderly Caucasians. It tends to metastasize to regional lymph nodes and viscera and is sensitive to chemotherapy but recurs rapidly. AIM: To report one such case, its response to chemotherapy and briefly review the literature. METHODS: A 73-year-old male with a fungating primary lesion on his left knee and ulcerated inguinal lymph nodes was diagnosed with MCC and treated with chemotherapy. The two largest case series and reviews of case reports were summarised. RESULTS: His ulcer healed after two cycles of carboplatin and etoposide with improvement in quality of life. Overall response rates of nearly 60% to chemotherapy are reported but median survival is only nine months with metastatic disease. CONCLUSIONS: Chemotherapy should be considered for fit elderly patients with MCC who have recurrent or advanced disease.

Ultrasound of non-vascular complications in the post liver transplant patient.

Vascular complications after liver transplantation are readily detected with ultrasound (US) and are well described. Less attention has been paid to non-vascular complications of liver transplantation, which are equally readily detected on US without the need to recourse to further imaging. The types, frequency and features of non-vascular complications are described in this review, with emphasis on biliary complications, types of fluid collections and the features of post-transplant lymphoproliferative disorder.

Smoking-related interstitial lung diseases: histopathological and imaging perspectives.

The present review focuses on the interstitial lung diseases related to smoking. Thus, the pathology and radiology of Langerhans cell histiocytosis, desquamative interstitial pneumonia, respiratory bronchiolitis and respiratory bronchiolitis-associated-interstitial lung disease are considered. The more tenuous association between pulmonary fibrosis and smoking is also discussed.

Hepatic artery stenosis following liver transplantation: significance of the tardus parvus waveform and the role of microbubble contrast media in the detection of a focal stenosis.

PURPOSE: To evaluate the role of microbubble ultrasound contrast media in detecting stenosis of the post-liver transplant extrahepatic hepatic artery (HA) in the presence of the tardus parvus spectral Doppler waveform of the intrahepatic HA. MATERIALS AND METHODS: All post-liver transplant patients with a prolonged systolic acceleration time (SAT>0.08s) and/or a reduced resistant index (RI<0.50) of the HA (the tardus parvus waveform) on colour Doppler ultrasound (CDUS), were assessed with microbubble contrast medium for a focal arterial stenosis. Following microbubble contrast-enhanced CDUS, patients underwent arteriography or follow-up CDUS. RESULTS: A total of 2038 examinations were performed in 529 liver transplant recipients; 16 (3.02%) tardus parvus waveforms were identified. The median SAT of the intrahepatic HA was 0.18s (range 0.11-0.38s) and the RI 0.47 (range 0.22-0.58). No extrahepatic elevated peak systolic velocity (PSV), defined as above 1.00m/s, was detected on the baseline examinations. Following the administration of microbubble contrast, medium, PSV in the extrahepatic HA was elevated in 14 of 16 patients, (median=2.15m/s, range=1.44-3.10m/s); flow was not identified in two patients. Arteriography was performed in 10 patients and confirmed stenosis in eight (median grade of stenosis 93%, range 60-99%) and occlusion in two. The measured median PSV at contrast-enhanced CDUS in the stenosis group was 2.03m/sec (range 1.44-2.71m/sec). Repeat CDUS in six patients not undergoing arteriography showed resolution in four; one underwent re-transplantation before arteriography and one patient maintains a tardus parvus waveform. In transplant recipients undergoing arteriography during the study period (n=55), no hepatic artery stenosis without a tardus parvus waveform was seen. CONCLUSION: The tardus parvus waveform pattern is an excellent screening test for the presence of post-liver transplantation hepatic artery stenosis. There is only a limited role for microbubble ultrasound contrast agent in the presence of a tardus parvus waveform. It could be used following equivocal colour Doppler ultrasound, but arteriography will still be necessary.

Clinical use of Levovist, an ultrasound contrast agent, in the imaging of liver transplantation: assessment of the pre- and post-transplant patient.

Colour Doppler US is well established for imaging of hepatic vessels in the assessment of pre- and post-liver transplant patients. Unfortunately, a full colour Doppler US examination of the portal or hepatic venous and hepatic arterial systems is frequently precluded by technical factors. Ultrasound contrast agents are useful in enhancing vascular Doppler signal and play an important role in liver transplantation assessment. A series of patients with vascular problems illustrates the role of US contrast in the pre-transplant candidate, where portal vein patency and direction of flow is assessed, presence of portal vein thrombus is confirmed and cavernous transformation demonstrated. Occlusion of hepatic veins in Budd-Chiari syndrome is confidently confirmed. Following liver transplantation, US contrast allows a comprehensive assessment of hepatic artery thrombosis, hepatic artery stenosis and pseudoaneurysm formation. The need for further imaging is reduced or confidently deferred in many instances. Ultrasound contrast agents play an important role in the liver transplant candidate.

A comparative evaluation of femorofemoral crossover bypass and iliofemoral bypass for unilateral iliac artery occlusive disease.

The purpose of this study was to compare the results of extra-anatomic femorofemoral crossover bypass grafting to the anatomic iliofemoral bypass grafting procedure in the treatment of patients with unilateral iliac artery occlusive disease with respect to patency and limb salvage. The records of all patients with unilateral iliac artery disease who underwent revascularization between January 1988 and December 1995 at the University of Iowa Hospitals and Clinics (UIHC) were retrospectively reviewed; 108 patients were identified and divided into two groups. Group I (n=68; male/female=44/24) was composed of all patients who underwent a femorofemoral crossover extra-anatomic bypass. All patients who underwent an iliofemoral anatomic bypass constituted group II (n=40; male/female=24/16). The mean age for group I was 60 years (range 28-87) and for group II, 54 years (range 14-86). The medical risk factors between both groups were comparable. Except for the higher incidence of gangrene in group II the indications for surgery were comparable between both groups. A polytetrafluoroethylene graft was used in 88% of group I patients and in 90% of group II patients (NS). In the remaining patients, an autogenous vein conduit was used. Two patients from group I (2.9%) died in the perioperative period (NS). Graft patency was assessed by clinical evaluation, Doppler-derived ankle/brachial indices, and color duplex imaging. The cumulative primary and secondary patency rates, limb salvage, and patient survival were calculated by use of life table analysis (SE<0.1). The need for simultaneous outflow and inflow procedures at the time of surgery was comparable between both groups. The proportion of patients who underwent further revascularization during follow-up was also comparable. The 5-year primary and secondary graft patency rates were 81.7% and 90.3%, in group I and 61.3% and 80.5% in group II. Although the difference between both groups was not significant there was a tendency toward higher rates with femorofemoral bypass. The 5-year survival rates of 80.3% for group I and 73.3% for group II were comparable. These data suggest that there is no significant difference in the long-term results between the femorofemoral crossover bypass grafts and iliofemoral grafts. Both procedures result in acceptable patency and limb salvage rates. The femorofemoral bypass is, however, more attractive, for it can be performed under local anesthesia if needed and does not involve the creation of the retroperitoneal incision necessary with the iliofemoral bypass.

Is color duplex surveillance of infrainguinal polytetrafluoroethylene grafts worthwhile?

BACKGROUND: Unlike vein bypasses, the role of duplex surveillance of infrainguinal prosthetic bypass grafts is controversial. The purpose of this study was to evaluate the adequacy of color duplex surveillance in identifying failing infrainguinal polytetrafluoroethylene (PTFE) bypass grafts and to assess its value in predicting continued bypass patency. METHOD: The surveillance data of primarily patent PTFE bypass grafts were compared with those of revised/occluded PTFE grafts. Ninety-five patients underwent 102 infrainguinal PTFE bypass grafts from January 1991 to December 1996 and were enrolled in a duplex surveillance program at 1 month postoperatively, every 3 months in the first year, every 6 months in the second year, and yearly thereafter. RESULTS: Seventy grafts remained primarily patent, 5 were revised and 27 occluded. There was no significant difference in the mean age, gender, indication for surgery, type of original procedure, or duration of follow-up between both groups. Four hundred and seven duplex surveillance data were available for analysis. Focal increase in peak systolic velocity (PSV) 3 x the adjacent segment or low flow manifested by PSV <45 cm/sec were considered abnormal. In the primarily patent group, 5 bypasses had abnormal duplex surveillance and were found to have no abnormality on angiogram and remained patent during the study period. In the revised/occluded group, duplex surveillance was abnormal in 8 bypasses. Twenty-four bypasses occluded without any predicting abnormalities on their last duplex examination, which was performed within 3 months from the occlusion in the majority of the patients. In the 27 occluded bypasses, no intervention was necessary following the occlusion in 7 grafts because of mild or no symptoms. Two patients were treated with a primary amputation and 2 had new bypasses. In 16 occluded grafts, salvage of the PTFE bypass was attempted. Ten of these grafts were patent at the end of the follow-up. The sensitivity of duplex surveillance was 25% with a positive predictive value of 61.5%. CONCLUSION: Duplex surveillance of infrainguinal PTFE bypass grafts has a low yield and is inadequate at predicting continued bypass patency.

Family enhancement of cognitive style in anxious and aggressive children.

Previous research has shown that anxious adults provide more threat interpretations of ambiguous stimuli than other clinic and nonclinic persons. We were interested in investigating if the same bias occurs in anxious children and how family processes impact on these children's interpretations of ambiguity. Anxious, oppositional, and nonclinical children and their parents were asked separately to interpret and provide plans of action to ambiguous scenarios. Afterwards, each family was asked to discuss two of these situations as a family and for the child to provide a final response. The results showed that anxious and oppositional children were both more likely to interpret ambiguous scenarios in a threatening manner. However, the two clinic groups differed in that the anxious children predominantly chose avoidant solutions whereas the oppositional children chose aggressive solutions. After family discussions, both the anxious children's avoidant plans of action and the oppositional children's aggressive plans increased. Thus, this study provides the first evidence of family enhancement of avoidant and aggressive responses in children. These results support a model of anxiety that emphasizes the development of an anxious cognitive style in the context of anxiety-supporting family processes.

Increases in pulse pressure impair acetylcholine-induced vascular relaxation.

Effects of pulse pressure on acetylcholine-induced endothelium-dependent relaxation were investigated using a cascade bioassay model. Intact carotid arteries from rabbits were perfused at constant flow, and activity of endothelium-derived relaxing factor (EDRF) was assayed by measuring changes in isometric tension in a detector ring without endothelium. When pulse pressure of the donor artery was raised from approximately 2 to 10 mmHg, relaxation to acetylcholine (10(-7) M) was reduced from 31 +/- 3 (means +/- SE) to 20 +/- 2% (expressed as percent relaxation of phenylephrine-induced tone). Responses of the detector ring to nitroprusside were unchanged. Superoxide dismutase (SOD) and indomethacin each prevented impairment of relaxation to acetylcholine at high pulse pressure. When the donor artery was perfused at a higher mean pressure, elevation of pulse pressure also impaired relaxation to acetylcholine, and this impairment was prevented by SOD. These findings suggest that elevation of pulse pressure inhibits acetylcholine-induced, endothelium-dependent relaxation, and this inhibitory effect is mediated by generation of oxygen radicals.

Gender- and age-related differences in heart rate dynamics: are women more complex than men?

OBJECTIVES: This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND: Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS: We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS: Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS: High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

Attachment style and affect regulation: relationships with health behavior and family experiences of illness in a student sample.

Questionnaire measures of attachment style and health behavior were completed by 287 university students on 2 occasions, 10 weeks apart. At Time 1, Ss also provided reports of emotionality and early family experiences of illness. Reports of early family illness showed theoretically meaningful relationships with attachment style. Symptom reporting was predicted most strongly by anxious/ambivalent attachment and negative emotionality, with the link between anxious/ambivalent attachment and symptom reporting partially mediated by negative emotionality. Visits to health professionals at Time 2 were directly related to reports of chronic illness in the family but inversely related to paternal illness and avoidant attachment, controlling for symptom reporting. The results are discussed in terms of theories of attachment and affect regulation.

Hemodynamic and autonomic nervous system responses to mixed meal ingestion in healthy young and old subjects and dysautonomic patients with postprandial hypotension.

BACKGROUND: Although postprandial hypotension is a common cause of falls and syncope in elderly persons and in patients with autonomic insufficiency, the pathophysiology of this disorder remains unknown. METHODS AND RESULTS: We examined the hemodynamic, splanchnic blood pool, plasma norepinephrine (NE), and heart rate (HR) power spectra responses to a standardized 400-kcal mixed meal in 11 healthy young (age, 26 +/- 5 years) and nine healthy elderly (age, 80 +/- 5 years) subjects and 10 dysautonomic patients with symptomatic postprandial hypotension (age, 65 +/- 16 years). Cardiac and splanchnic blood pools were determined noninvasively by radionuclide scans, and forearm vascular resistance was determined using venous occlusion plethysmography. In healthy young and old subjects, splanchnic blood volume increased, but supine blood pressure remained unchanged after the meal. In both groups, HR increased and systemic vascular resistance remained stable. Forearm vascular resistance and cardiac index increased after the meal in elderly subjects, whereas these responses were highly variable and of smaller magnitude in the young. Young subjects demonstrated postprandial increases in low-frequency HR spectral power, representing cardiac sympatho-excitation, but plasma NE remained unchanged. In elderly subjects, plasma NE increased after the meal but without changes in the HR power spectrum. Patients with dysautonomia had a large postprandial decline in blood pressure associated with no change in forearm vascular resistance, a fall in systemic vascular resistance, and reduction in left ventricular end diastolic volume index. HR increased in these patients but without changes in plasma NE or the HR power spectrum. CONCLUSIONS: 1) In healthy elderly subjects, the maintenance of blood pressure homeostasis after food ingestion is associated with an increase in HR, forearm vascular resistance, cardiac index, and plasma NE. In both young and old, systemic vascular resistance is maintained. 2) Dysautonomic patients with postprandial hypotension fail to maintain systemic vascular resistance after a meal. This impairment in vascular response to meal ingestion may underlie the development of postprandial hypotension. 3) The measurement of mean HR or plasma NE does not adequately characterize autonomic cardiac control. Power spectral analysis suggests an impairment in the postprandial autonomic modulation of HR in healthy elderly and dysautonomic subjects, possibly predisposing to hypotension when vascular compensation is inadequate.

A reading-level design study of phonological skills underlying fourth-grade children's word reading difficulties.

A 3-group reading-level design was used to investigate phonological analysis, verbal working memory, and pseudoword reading performance in less skilled fourth-grade readers. Children were given phonological oddity tasks assessing their sensitivity to subsyllabic and phonemic units, together with standardized tests of verbal working memory and pseudoword reading. Less skilled fourth-grade readers performed lower than both chronological age and reading-level controls on the phonological oddity and pseudoword reading tests. Less skilled fourth-grade readers performed at the same level as skilled second-grade readers on a test of verbal working memory. Skilled fourth-grade readers scored higher than both other groups on this test. Correlational analyses were consistent with the view that phonological analysis skills contribute more strongly than verbal working memory skills to children's decoding abilities.