The subjective experience of pain: where expectations become reality

Our subjective sensory experiences are thought to be heavily shaped by interactions between expectations and incoming sensory information. However, the neural mechanisms supporting these interactions remain poorly understood. By using combined psychophysical and functional MRI techniques, brain activation related to the intensity of expected pain and experienced pain was characterized. As the magnitude of expected pain increased, activation increased in the thalamus, insula, prefrontal cortex, anterior cingulate cortex (ACC) and other brain regions. Pain-intensity-related brain activation was identified in a widely distributed set of brain regions but overlapped partially with expectation-related activation in regions, including the anterior insula and ACC. When expected pain was manipulated, expectations of decreased pain powerfully reduced both the subjective experience of pain and activation of pain-related brain regions, such as the primary somatosensory cortex, insular cortex, and ACC. These results confirm that a mental representation of an impending sensory event can significantly shape neural processes that underlie the formulation of the actual sensory experience and provide insight as to how positive expectations diminish the severity of chronic disease states.

Does ethnicity influence the prevalence of adrenal hyperandrogenism and insulin resistance in polycystic ovary syndrome?

OBJECTIVE

Our purpose was to determine the prevalence of adrenal hyperandrogenism and insulin resistance in patients with hyperandrogenic chronic anovulation, also called polycystic ovary syndrome, living in the United States, Italy, and Japan.

STUDY DESIGN

Seventy-five women with polycystic ovary syndrome, 25 each from the United States, Italy, and Japan, and 10 ovulatory controls were studied. Hirsutism, obesity, and the presence of cystic ovaries were assessed, as were blood levels for estrogen, luteinizing hormone, testosterone, adrenal androgens, and insulin. All patients received an insulin tolerance test to assess insulin resistance.

RESULTS

Women from Japan were less obese (p < 0.05) and did not have hirsutism, although the percentage of cystic ovaries (68% to 80%) was comparable. Serum luteinizing hormone, testosterone, and estradiol were similar, but levels of 3 alpha-androstanediol glucuronide, which was elevated in women from the United States and Italy, was normal in women from Japan. The adrenal androgens, dehydroepiandrosterone sulfate and 11 beta-hydroxyandrostenedione were elevated in 48% to 64% of the patients and by a similar percentage in the three groups. Fasting insulin was elevated in all groups, but was significantly higher in women from the United States and Italy compared with women from Japan (p < 0.05). However, insulin resistance as assessed by dissociation constant of insulin tolerance test values was significantly elevated but similar in the three groups and occurred in 68% to 76% of patients.

CONCLUSION

In polycystic ovary syndrome, although obesity and hirsutism vary according to dietary, genetic, and environmental factors, the prevalence of adrenal androgen excess and insulin resistance appear to be fairly uniform. These results suggest that these factors may be involved in the pathophysiologic features of the disorder.

Unusual appearances of uterine leiomyomas: MR imaging findings and their histopathologic backgrounds

Typical appearances of uterine leiomyoma at magnetic resonance (MR) imaging are well established, and diagnosis is usually easy. However, cases that, are extremely difficult to differentiate from other conditions are occasionally encountered. To understand the wide spectrum of MR imaging findings, such unusual appearances can be classified into three categories: degeneration and other histopathologic findings, specific types of unusual leiomyomas, and unusual growth patterns. The common types of degeneration are hyaline (>60% of cases), cystic (approximately 4%), myxoid, and red. Edema is not a phenomenon of degeneration but is a common histopathologic finding (approximately 50% of cases). Hemorrhage, necrosis, and calcification (approximately 4% of cases) may also be observed. Specific types of unusual leiomyomas include lipoleiomyoma and myxoid leiomyoma, which may have MR imaging features characteristic enough to allow differentiation from other gynecologic and nongynecologic diseases. Intravenous leiomyomatosis, metastasizing leiomyoma, diffuse leiomyomatosis, and peritoneal disseminated leiomyomatosis represent unusual growth patterns; other unusual growth patterns are retroperitoneal growth, parasitic growth, and the pattern that may occur in cervical leiomyoma. Because leiomyomas are the most common gynecologic tumors and are exclusively benign, it is important to be familiar with the variety of MR imaging appearances of uterine leiomyomas to distinguish them from other significant diseases.

Regional changes in dopamine and serotonin activation with various intensity of physical and psychological stress in the rat brain

The present study examined whether regional patterns of brain dopamine (DA) and serotonin (5-HT) activation after physical and psychological stress depend on the intensity of that stress. Monoamine concentrations (DA, 5-HT, and their metabolites) were measured using high-performance liquid chromatography with electrochemical detection in eight brain regions of rats exposed to two different intensities of foot shock stress for 30 min (1.5 mA or 2.5 mA) or conditioned fear stress (CFS, after single or repeated foot shock). A low level of foot shock selectively increased the DA metabolism in the medial prefrontal cortex (mPFC), whereas a high level of foot shock increased it in most of the brain regions examined in the present study. A low level of foot shock did not increase the 5-HT metabolism in any regions, but a high-intensity shock increased the 5-HT metabolism in the mPFC, nucleus accumbens, and lateral hypothalamus. Rats that received high-intensity shock displayed more freezing than those that received low-intensity shock in a conditioned fear paradigm (24 h after receiving foot shock, the animals were placed in a shock chamber without being given shock), indicating an augmentation of conditioned fear. The increased DA and 5-HT metabolism were especially marked in the mPFC after CFS following a single foot shock session (2.5 mA). Rats that were repeatedly exposed to 2.5 mA foot shock for a period of 10 days displayed a greater degree of freezing induced by CFS than those given only one foot shock session, indicating an augmentation of fear and stress intensity. CFS after repeated foot shock, like foot shock per se, increased the DA metabolism in most of the brain regions except for the striatum and increased the 5-HT metabolism in the mPFC, nucleus accumbens, and amygdala. These results suggest that regional patterns of brain DA and 5-HT activation after physical and psychological stress depend on the intensity of that stress, although there are some differences between these stress; and that the more widespread activation of DA and 5-HT after more severe stress might relate to behavioral changes that reflect the augmentation of fear.

Proportion of reflux esophagitis in 6010 Japanese adults: prospective evaluation by endoscopy

Compared with findings in Western countries, the prevalence of reflux esophagitis in Oriental countries is estimated to be low. In this prospective study, we aimed to examine the proportion of reflux esophagitis in Japanese adults, as evaluated by endoscopy. Endoscopists were prospectively directed to grade esophageal mucosal breaks with esophagitis according to the Los Angeles Classification of Esophagitis in all subjects that underwent endoscopic examination. In total, 6010 subjects underwent endoscopic examination for evaluation of esophagitis grading from December 1996 to February 1998. The subjects included 4394 outpatients who were not receiving medication for gastrointestinal disease and 1616 subjects who visited the hospital for routine physical examinations. The overall proportion of esophagitis was 16.3%. Most of the subjects with esophagitis were classified as having grade A or B (proportion of grades A and B, 9.6% and 4.6%, respectively). The age-related proportion of esophagitis and of severe esophagitis (i.e., grades C and D) increased in females aged over 70 and in males aged over 80. Increased body mass index (partly due to decreased height caused by osteoporosis), and/or hiatal herniation, were related to the proportion of esophagitis in females aged over 70. These data indicated that reflux esophagitis is a common disease in Japan. However, severe esophagitis (grades C and D) is not common.

The morbidity, time course and predictive factors for persistent post-thoracotomy pain

After thoracotomy, patients often suffer from a persistent pain syndrome called post-thoracotomy pain. To elucidate morbidity, time course, and predictive factors for this syndrome, we analyzed follow-up data for 85 post-thoracotomy patients. We used a four-point scale to assess pain: none, slight, moderate and severe. Of 85 patients, 50 reported pain (39 slight, 11 moderate) one day after surgery. A year after surgery, the patients were polled using a simple questionnaire received by the mail. Sixty patients reported persistent pain (34 slight, 14 moderate, 12 severe) a month after surgery, and 35 patients reported persistent pain (33 slight, two moderate) around the time of the poll (1 year after surgery). Although pain deterioration was observed in 40% (34/85) of patients during month 1 after surgery, pain alleviation was seen in 48% (41/85) of patients during months 2-12. Stepwise regression analysis revealed that female gender and pain at postoperative day 1 were predictive for persistent pain both 1 month and 1 year after thoracotomy. Among 35 patients with persistent pain 1 year after surgery, 24 cases reported paresthesia-dysesthesia, and 14 cases reported hypoesthesia. The present data thus suggests that persistent pain is common and often severe 1 month after surgery but is alleviated after 1 year. Clinical time course and symptoms indicate that nerve impairment rather than simple nociceptive impact may be involved in this syndrome.

Nociceptive neurons in the macaque anterior cingulate activate during anticipation of pain

Since the anterior cingulate cortex (ACC) is known to be involved both in nociception and in anticipation that precedes the avoidance of aversive stimuli, the linking of these functions may be processed in the ACC. To test this hypothesis, we recorded single neuronal activities in the ACC of a macaque monkey while it was performing a pain-avoidance task and examined them with nociceptive cutaneous electric stimuli (ES). Thirty-six neurons responded in anticipation of the ES. Of these, 22 neurons were tested with the ES and 11 responded. These neurons could be those that are involved both in nociception and in pain anticipation that precedes the avoidance of noxious stimuli.

Association of the human NPPS gene with ossification of the posterior longitudinal ligament of the spine (OPLL)

OPLL (ossification of the posterior longitudinal ligament of the spine) is a common form of human myelopathy with a prevalence of as much as 4% in a variety of ethnic groups. To clarify the genetic factors that predispose to OPLL, we have studied ttw (tiptoe walking), a mouse model that presents ectopic ossification of the spinal ligaments similar to OPLL and have found that the ttw phenotype is caused by the nonsense mutation of the gene encoding nucleotide pyrophosphatase (NPPS), a membrane-bound glycoprotein thought to produce inorganic pyrophosphate, a major inhibitor of calcification and mineralization. To investigate a possible role of NPPS in the etiology of OPLL, we have examined its genetic variations in OPLL patients. A total of 323 OPLL patients was screened by means of polymerase chain reaction/single-strand conformation polymorphism analysis covering all the exons and their surrounding introns, plus about 1.5-kb of the promoter region. We identified ten nucleotide variations in the NPPS gene; five of the alterations caused amino-acid substitutions, and two of them were found specifically in OPLL patients. Subsequently, we performed an association study using these variations and found a significant association of an allele, viz., a deletion of T at a position 11 nucleotides upstream from the splice acceptor site of intron 20 (IVS20-11delT), with OPLL; the proportion of the individuals having this deletion was significantly higher (P = 0.0029) in OPLL patients than in controls, indicating that those who have this variation may be more susceptible to the abnormal ossification of the spinal ligaments. Thus, our study suggests that NPPS plays an important role in the etiology of human OPLL.

Development of different phenotypes of hypertensive heart failure: systolic versus diastolic failure in Dahl salt-sensitive rats

OBJECTIVE

There are two phenotypes of heart failure, systolic failure and isolated diastolic heart failure with preserved left ventricular systolic function. Although isolated diastolic heart failure frequently occurs, there are only models for diastolic dysfunction unassociated with heart failure and models with overt diastolic heart failure have not been established. We attempted to develop two different models, i.e. diastolic and systolic failure models, based on hypertension.

MATERIALS AND METHODS

Dahl salt-sensitive rats were placed on 8% NaCl diet from 7 weeks old (7-week starting group) or 8 weeks old (8-week starting group). As an age-matched control, Dahl salt-sensitive rats were consistently placed on normal chow. In these rats, echocardiogram was serially recorded, followed by hemodynamic and histological studies.

RESULTS

The 7-week starting rats showed a steep elevation in blood pressure and progressive left ventricular hypertrophy, and fell into overt heart failure at approximately 19 weeks. The development of heart failure was not associated with a decrease in left ventricular midwall fractional shortening or an increase in left ventricular end-diastolic dimension as compared with the age-matched control, which mimics the characteristics of clinically observed isolated diastolic heart failure. The 8-week starting rats showed a gradual rise in blood pressure and less progressive left ventricular hypertrophy, and fell into heart failure at approximately 26 weeks with a decrease in mid-wall fractional shortening and an increase in left ventricular end-diastolic dimension. Hemodynamic and histological studies at failing stage revealed comparable elevation of left ventricular end-diastolic pressure and comparable left ventricular fibrosis in both groups.

CONCLUSION

These two different models of overt heart failure may be useful as models of isolated diastolic heart failure and systolic heart failure based on the same hypertensive heart disease, respectively, and may contribute to discrimination of the mechanisms of the development of the two different phenotypes of heart failure.

Crystal structure of cis-prenyl chain elongating enzyme, undecaprenyl diphosphate synthase

Undecaprenyl diphosphate synthase (UPS) catalyzes the cis-prenyl chain elongation onto trans, trans-farnesyl diphosphate (FPP) to produce undecaprenyl diphosphate (UPP), which is indispensable for the biosynthesis of bacterial cell walls. We report here the crystal structure of UPS as the only three-dimensional structure among cis-prenyl chain elongating enzymes. The structure is classified into a protein fold family and is completely different from the so-called "isoprenoid synthase fold" that is believed to be a common structure for the enzymes relating to isoprenoid biosynthesis. Conserved amino acid residues among cis-prenyl chain elongating enzymes are located around a large hydrophobic cleft in the UPS structure. A structural P-loop motif, which frequently appears in the various kinds of phosphate binding site, is found at the entrance of this cleft. The catalytic site is determined on the basis of these structural features, from which a possible reaction mechanism is proposed.

Results of microsurgical treatment for intramedullary spinal cord ependymomas: analysis of 36 cases

OBJECTIVE

Although intramedullary spinal cord ependymomas are amenable to surgical total resection, some ependymomas have been associated with severe surgical morbidity. The aim of this study is to determine what factors affect surgical morbidity.

METHODS

Thirty-six consecutive patients who underwent surgical removal of an intramedullary spinal cord ependymoma between September 1980 and June 1998 were studied retrospectively. This series includes 19 women and 17 men between the age of 12 and 67 years (mean age, 41.2 yr). The location of the tumors was cervical in 24 cases, cervicothoracic in 3 cases, thoracic in 7 cases, and conus in 2 cases. At surgery, complete removal was achieved in 34 patients and subtotal removal was performed in the remaining 2.

RESULTS

There has been no tumor recurrence in any patient except one who had an anaplastic ependymoma after a mean follow-up period of 56 months. The surgery improved neurological status in 14 of the 36 patients (39%). However, five patients (14%) experienced persistent deteriorations in clinical grade caused by surgery. Four of the five patients harbored benign ependymomas in the thoracic cord and characteristically demonstrated arachnoid scarring and cord atrophy at surgery, indicating that tumors had been present for a long time.

CONCLUSION

Surgical removal of intramedullary ependymomas is beneficial to patients. However, the thoracic cord may be susceptible to surgical manipulations for intramedullary ependymomas. In addition, intraoperative findings of arachnoid scarring and cord atrophy are ominous for surgical morbidity.

Effects of repeated administration of a high dose of methamphetamine on dopamine and glutamate release in rat striatum and nucleus accumbens

We examined effects of a high dose of methamphetamine (MA) (4.02 mg free base/kg, s.c., at 2-h intervals, 4 injections) on extracellular concentrations of monoamines such as dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) and those of glutamate and other several amino acids in rat striatum (ST) and nucleus accumbens (NA) using in vivo microdialysis. Five days after the microdialysis, tissue concentrations of monoamines were measured. The toxic dose of MA markedly increased extracellular concentrations of DA, and decreased those of DOPAC, HVA and 5-HIAA in both ST and NA. Magnitude of the increase in DA release was not different between ST and NA. Extracellular concentrations of glutamate showed a gradual increase in ST, but not in NA, while other amino acids showed no changes in both ST and NA. Tissue concentrations of serotonin (5-HT) and 5-HIAA were decreased to 43-58% of control values in both ST and NA, whereas those of DA, DOPAC and HVA showed 43-54% decrease in ST but no changes in NA. These data suggest that the marked increase of DA release is not directly related to the MA-induced dopaminergic neurotoxicity. The increase in glutamate release found only in ST may be related to the dopaminergic damage in ST. It may be that enhanced release in DA and glutamate act synergistically to cause the dopaminergic neurotoxicity in ST. However, enhancement in glutamate release did not appear to be essential for the MA-induced serotonergic neurotoxicity.

Raised serum APRIL levels in patients with systemic lupus erythematosus

OBJECTIVE

To determine whether serum levels of a proliferation-inducing ligand (APRIL) are raised in patients with systemic lupus erythematosus (SLE) and correlate with autoantibody titres or disease activity, or both.

METHODS

Serum samples from 48 patients with SLE, 41 normal healthy subjects, and 21 patients with rheumatoid arthritis (RA) were assayed for APRIL by enzyme linked immunosorbent assay. Medical charts were retrospectively reviewed for autoantibody titres and immunoglobulin levels. Disease activity was assessed using the British Isles Lupus Assessment Group (BILAG) index.

RESULTS

The APRIL levels in the serum samples from patients with SLE were significantly higher than in those from healthy controls and those from patients with RA. Serum APRIL levels did not correlate with serum IgG and IgM levels, but had a tendency to correlate with anti-double stranded DNA antibody titres. Moreover, serum APRIL levels correlated significantly with musculoskeletal manifestations among patients with SLE when assessed by the BILAG index.

CONCLUSION

APRIL may be an important factor in raised autoantibody titres and musculoskeletal disease in patients with SLE. Patients with raised serum APRIL levels may be ideal candidates for therapeutic targeting of APRIL.

Expressional screening of interferon-stimulated genes for antiviral activity against hepatitis C virus replication

Type-I interferons (IFNs) and the interferon-stimulated genes (ISGs) play a major role in antivirus responses against hepatitis C virus (HCV) infection. In this study, we studied expression profiles of ISGs in cells supporting subgenomic HCV replication (Huh7/Rep), and screened their activities to suppress HCV replication. Real-time PCR analyses showed that the expression levels of 23 ISGs were significantly lower in Huh7/Rep than naive Huh7 cells due to transcriptional suppression of the interferon-stimulated response element (ISRE). Furthermore, the expression level of ISGs was also decreased in the cured Huh7 cells in which replicon had been eliminated (cHuh7), indicating adaptation of the cells to support HCV replication by downregulating ISGs. On the other hand, expression of HCV replicon was significantly suppressed by overexpression of several ISGs including PKR, MxA, IRF-9, GBP-1, IFI-6-16, IFI-27, 25OAS and IRF-1. Knock down of GBP-1, IFI-6-16 and IFI-27 by short hairpin RNA resulted in increase of HCV replication. Thus, we conclude that downregulation of ISG expression is required in the host cells supporting HCV replication and that several ISGs directly suppress HCV replication. The search for ISGs that regulate HCV replication may help to elucidate the cellular antiviral defence mechanisms against HCV infection.

Conversion from farnesyl diphosphate synthase to geranylgeranyl diphosphate synthase by random chemical mutagenesis

Prenyltransferases catalyze the consecutive condensation of isopentenyl diphosphate (IPP) with allylic diphosphates to produce prenyl diphosphates whose chain lengths are absolutely determined by each enzyme. In order to investigate the mechanisms of the consecutive reaction and of the determination of ultimate chain length, a random mutational approach was planned. The farnesyl diphosphate (FPP) synthase gene of Bacillus stearothermophilus was subjected to random mutagenesis by NaNO2 treatment to construct libraries of mutated FPP synthase genes on a high-copy plasmid. From the libraries, the mutants that showed the activity of geranylgeranyl diphosphate (GGPP) synthase were selected by the red-white screening method (Ohnuma, S.-i., Suzuki, M., and Nishino, T. (1994) J. Biol. Chem. 268, 14792-14797), which utilized carotenoid synthetic genes, phytoene synthase, and phytoene desaturase, to visualize the formation of GGPP in vivo. Eleven red positive clones were identified from about 24,300 mutants, and four (mutant 1, 2, 3, and 4) of them were analyzed for the enzyme activities. Results of in vitro assays demonstrated that all these mutants produced (all-E)-GGPP although the amounts were different. Each mutant was found to contain a few amino acid substitutions: mutant 1, Y81H and L275S; mutant 2, L34V and R59Q; mutant 3, V157A and H182Y; mutant 4, Y81H, P239R, and A265T. Site-directed mutagenesis showed that Y81H, L34V, or V157A was essential for the expression of the activity of GGPP synthase. Especially, the replacement of tyrosine 81 by histidine is the most effective because the production ratios of GGPP to FPP in mutant 1 and 4 are the largest. Based on prediction of the secondary structure, it is revealed that the tyrosine 81 situates on a point 11 approximately 12 A apart from the first DDXXD motif, whose distance is similar to the length of hydrocarbon moiety of FPP. These data might suggest that the aromatic ring of tyrosine 81 blocks the chain elongation longer than FPP. Comparisons of kinetic parameters of the mutated and wild type enzymes revealed several phenomena that may relate with the change of the ultimate chain length. They are a decrease of the total reaction rate, increase of Kmfor dimethylallyl diphosphate, decrease of Vmax for dimethylallyl diphosphate, and allylic substrate dependence of Km for IPP.

1alpha,25-dihydroxyvitamin D(3) and its potent synthetic analogs downregulate tissue factor and upregulate thrombomodulin expression in monocytic cells, counteracting the effects of tumor necrosis factor and oxidized LDL

BACKGROUND

We have recently found that a hormonally active form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], exerts anticoagulant effects by upregulating the expression of an anticoagulant glycoprotein, thrombomodulin (TM), and downregulating the expression of a critical coagulation factor, tissue factor (TF), in monocytic cells including human peripheral monocytes. In this study, we investigated the counteracting effects of 1,25(OH)(2)D(3) and its potent analogs on TF induction and TM downregulation by tumor necrosis factor and oxidized LDL in monocytic cells and the modulatory effects of potent analogs on TF and TM expression.

METHODS AND RESULTS

Effects of 1,25(OH)(2)D(3) and its potent synthetic analogs (22R)-22-methyl-20-epi-1,25(OH)(2)D(3) (KY3) and 22-oxacalcitriol on TF and TM antigen levels, cell surface activities, and mRNA levels in monocytic cells were examined. 1, 25(OH)(2)D(3) and its potent analogs showed anticoagulant effects in monocytic cells by downregulating TF and upregulating TM expression, counteracting the effects of tumor necrosis factor and oxidized LDL. KY3 was most potent in its regulatory effect on TF and TM expression.

CONCLUSIONS

Because KY3 has the highest affinity for vitamin D receptor, our findings suggest that TF and TM regulation by 1, 25(OH)(2)D(3) analogs is also mediated by vitamin D receptor. The 1, 25(OH)(2)D(3) analogs KY3 and 22-oxacalcitriol may have the potential to serve as an agent for preventing and treating atherosclerotic and other cytokine-mediated thrombotic diseases and as a tool for studying the molecular mechanisms of TF and TM regulation.

Thermostable farnesyl diphosphate synthase of Bacillus stearothermophilus: molecular cloning, sequence determination, overproduction, and purification

The structural gene for thermostable farnesyl diphosphate synthase from Bacillus stearothermophilus was cloned, sequenced, and overexpressed in Escherichia coli cells. A 1,260-nucleotide sequence of the cloned fragment was determined. This sequence specifies an open reading frame of 891 nucleotides for farnesyl diphosphate synthase. The deduced amino acid sequence shows a 42% similarity with that of E. coli FPP synthase [Fujisaki et al. (1990) J. Biochem. 108, 995-1000]. Comparison with prenyltransferases from a wide range of organisms, from bacteria to human, revealed the presence of seven highly conserved regions. In contrast to thermolabile prenyltransferases, which have four to six cysteine residues, the thermostable farnesyl diphosphate synthase carries only two cysteine residues. This enzyme is also unique in that some of the amino acids that are fully conserved in equivalents from other sources are replaced by functionally different amino acids. Construction of an overproducing strain provided a sufficient supply of this enzyme and it was purified to homogeneity. The purified recombinant enzyme is immunochemically identical with the native B. stearothermophilus enzyme, and it is not inactivated even after treatment at 65 degrees C for 70 min.

Dermoid cysts of the ovary with malignant transformation: MR appearance

OBJECTIVE

This study presents the MR appearances of five women with a total of six proven dermoid cysts of the ovary with malignant transformation. To our knowledge, the MR findings of this entity have not been reported.

CONCLUSION

The lesions appeared to be fat-containing tumors with a solid component (4/6) that extended transmurally (4/6) and extensively invaded neighboring pelvic organs (3/6). The supervening malignancy was squamous cell carcinoma in four tumors, melanoma in one, and transitional cell carcinoma in one. The mode of spread differed from that of common ovarian tumors in that it included transmural extension and local invasion, reflecting squamous cell carcinoma.

Effects of conditioned fear stress on serotonin neurotransmission and freezing behavior in rats

In an attempt to clarify the role of the brain serotonergic system in the psychopathology of anxiety, we examined the effect of a psychological stress, conditioned fear stress, on extracellular serotonin (5-hydroxytryptamine, 5-HT) concentrations in the rat medial prefrontal cortex using the method of in vivo microdialysis, while simultaneously observing conditioned fear stress-induced freezing behavior, an index of anxiety. Conditioned fear stress increased extracellular 5-HT levels in the medial prefrontal cortex, and this 5-HT level increase was followed by a resolution of the freezing behavior. A dose of 10 mg/kg of a selective 5-HT reuptake inhibitor, citalopram, administered 60 min before exposure to conditioned fear stress increased extracellular 5-HT concentrations immediately and potently, reducing freezing behavior. These findings strongly suggest that facilitation of brain 5-HT neurotransmission decreases anxiety, which is in agreement with the clinical reports that selective 5-HT reuptake inhibitors are effective in the treatment of anxiety disorders.

Comparison of manual and automatic segmentation methods for brain structures in the presence of space-occupying lesions: a multi-expert study

The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, of 20 patients who underwent therapy for large space-occupying tumors. Performance variability was assessed through three geometric measures: volume, Dice similarity coefficient, and Euclidean distance. In addition, two simulated ground truth segmentations were calculated via the simultaneous truth and performance level estimation algorithm and a novel application of probability maps. The experts and automatic system were found to generate structures of similar volume, though the experts exhibited higher variation with respect to tubular structures. No difference was found between the mean Dice similarity coefficient (DSC) of the automatic and expert delineations as a group at a 5% significance level over all cases and organs. The larger structures of the brainstem and eyes exhibited mean DSC of approximately 0.8-0.9, whereas the tubular chiasm and nerves were lower, approximately 0.4-0.5. Similarly low DSCs have been reported previously without the context of several experts and patient volumes. This study, however, provides evidence that experts are similarly challenged. The average maximum distances (maximum inside, maximum outside) from a simulated ground truth ranged from (-4.3, +5.4) mm for the automatic system to (-3.9, +7.5) mm for the experts considered as a group. Over all the structures in a rank of true positive rates at a 2 mm threshold from the simulated ground truth, the automatic system ranked second of the nine raters. This work underscores the need for large scale studies utilizing statistically robust numbers of patients and experts in evaluating quality of automatic algorithms.

Serotonin reuptake inhibitors reduce conditioned fear stress-induced freezing behavior in rats

Conditioned fear stress (CFS)-induced freezing behavior has been proposed as an animal model of anxiety. In the present study, freezing was used to determine the anxiolytic activity of selective serotonin reuptake inhibitors (SSRIs), which are reported to be clinically effective in anxiety disorders. The duration of freezing behavior was reduced by acute treatment with the SSRIs citalopram (1-10 mg/kg) and fluvoxamine (3-30 mg/kg). Acute treatment with the serotonin (5-HT)/noradrenaline (NA) mixed reuptake inhibitor milnacipran (3-30 mg/kg) also attenuated CFS-induced freezing, while acute treatment with the NA reuptake inhibitors maprotiline and ORG4428, and the dopamine (DA) reuptake inhibitor GBR12909 failed to alter CFS-induced freezing. These results indicate that facilitation of 5-HT availability in the brain produced by 5-HT reuptake inhibition reduces CFS-induced freezing behavior. CFS may be a useful model for detecting the anxiolytic potential of 5-HT reuptake inhibitors.

Toward the best treatment for uncomplicated patients with type B acute aortic dissection: A consideration for sound surgical indication

BACKGROUND

In the treatment of type B acute aortic dissection without complications, better results are obtained if surgery is performed before enlargement of the aorta in patients who are predicted to show aortic enlargement and if drug-based treatment is continued for patients who are predicted to show no enlargement. The purpose of this study was to predict the acute-phase factors that may affect chronic-phase aortic enlargement by studying chronic-phase enlargement of dissections in patients without complications during the acute phase.

METHODS AND RESULTS

In 101 patients with type B acute dissection who had no complications, univariate and multivariate factor analyses were performed to determine the predictors for chronic-phase enlargement (>/=60 mm) of the dissected aorta. The independent predominant predictors for aortic enlargement in the chronic phase were a maximum aortic diameter of >/=40 mm and a patent false lumen during the acute phase. The values of actuarial freedom from aortic enlargement for the patients with a maximum aortic diameter of 40 mm and a patent false lumen at 1, 5, and 10 years were 43%, 33%, and 22%, respectively, whereas in patients with a maximum aortic diameter of <40 mm and a closed false lumen, the values were 97%, 94%, and 84%, respectively.

CONCLUSIONS

These results suggest that patients with type B acute aortic dissection who show a maximum aortic diameter of >/=40 mm and a patent false lumen should undergo surgery earlier during the chronic phase before enlargement of aorta, whereas patients with a maximum aortic diameter of <40 mm and a closed false lumen should continue to receive hypotensive therapy.

Low-dose erythromycin reduces delayed gastric emptying and improves gastric motility after Billroth I pylorus-preserving pancreaticoduodenectomy

OBJECTIVE

To test the hypothesis that early and low doses of erythromycin reduce the incidence of early delayed gastric emptying (DGE) and induce phase 3 of the migratory motor complex in the stomach after Billroth I pylorus-preserving pancreaticoduodenectomy (PPPD).

SUMMARY BACKGROUND DATA

Delayed gastric emptying is a leading cause of complications after PPPD, occurring in up to 50% of patients. High doses of erythromycin (200 mg) accelerate gastric emptying after pancreaticoduodenectomy and reduce the incidence of DGE, although they induce strong contractions that do not migrate to the duodenum.

METHODS

Thirty-one patients were randomly assigned to either the erythromycin or control groups. The patients received erythromycin lactobionate (1 mg/kg) every 8 hours, or H2-receptor antagonists and gastrokinetic drugs from days 1 to 14 after surgery. On postoperative day 30, gastroduodenal motility was recorded in 14 patients.

RESULTS

Preoperative, intraoperative, and postoperative factors were comparable in the erythromycin and control groups. The erythromycin group had a shorter duration of nasogastric drainage, earlier resumption of eating, and a 75% reduction in the incidence of DGE. Erythromycin was an independent influence on nasogastric tube removal, and preservation of the right gastric vessels was a significant covariate. Low doses of erythromycin induced phase 3 of the migratory motor complex and phase 3-like activity, with the same characteristics as spontaneous phase 3, in 86% of patients: two had quiescent stomachs and the others had spontaneous phase 3 or phase 3-like activity.

CONCLUSIONS

Low doses of erythromycin reduced the incidence of DGE by 75% and induced phase 3 of the migratory motor complex after Billroth I PPPD. Low doses of erythromycin are preferable to high doses in the unfed period after PPPD.

Determination of plasma tissue factor antigen and its clinical significance

To investigate the clinical significance of determination of plasma tissue factor (TF) antigen, we have developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) for plasma TF, using two different monoclonal antibodies against TF apoprotein, 6B4 (catching antibody) and 5G9 (detecting antibody), and tetramethyl benzidine/H2O2 as substrates. Titration curves of recombinant human TF in buffer containing Triton X-100 were linear within the range from 50 to 2000 pg/ml. The total assay time was 3 h. Ultracentrifugation and immunoblot analysis indicated that human plasma and urine contained 50,000 g sedimentable and non-sedimentable forms of TF, both of which were detected by our ELISA method. Plasma and urine concentrations of TF in healthy subjects and patients with various diseases were measured by the ELISA method. In healthy subjects, plasma and urinary TF levels were found to be 149 +/- 72 pg/ml (n = 30) and 175 +/- 60 pg TF/urine creatinine mg (n = 95), respectively. TF was increased in plasma of patients with disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura, vasculitis associated with collagen diseases, diabetic microangiopathy and chronic renal failure receiving haemodialysis, but not in the plasma of endotoxaemic patients without DIC. The plasma TF/serum creatinine ratio did not show a positive correlation. Measurement of TF antigen in plasma may be useful for evaluating the endothelial damage and cell destruction in TF-containing tissues.

Quantitative autistic traits ascertained in a national survey of 22 529 Japanese schoolchildren

OBJECTIVE

Recent epidemiologic studies worldwide have documented a rise in prevalence rates for autism spectrum disorders (ASD). Broadening of diagnostic criteria for ASD may be a major contributor to the rise in prevalence, particularly if superimposed on an underlying continuous distribution of autistic traits. This study sought to determine the nature of the population distribution of autistic traits using a quantitative trait measure in a large national population sample of children.

METHOD

The Japanese version of the Social Responsiveness Scale (SRS) was completed by parents on a nationally representative sample of 22 529 children, age 6-15.

RESULTS

Social Responsiveness Scale scores exhibited a skewed normal distribution in the Japanese population with a single-factor structure and no significant relation to IQ within the normal intellectual range. There was no evidence of a natural 'cutoff' that would differentiate populations of categorically affected children from unaffected children.

CONCLUSION

This study provides evidence of the continuous nature of autistic symptoms measured by the SRS, a validated quantitative trait measure. The findings reveal how paradigms for diagnosis that rest on arbitrarily imposed categorical cutoffs can result in substantial variation in prevalence estimation, especially when measurements used for case assignment are not standardized for a given population.