Optogenetic stimulation in the medial prefrontal cortex modulates stimulus valence from rewarding and aversive to neutral states

Introduction

Understanding the modulations of the medial prefrontal cortex (mPFC) in the valence of the stimulus from rewarding and aversive status to neutral status is crucial for the development of novel treatments for drug addiction. This study addressed this issue and examined whether optogenetic ChR2 photostimulation in the cingulate, prelimbic, and infralimbic cortices of the mPFC regulated the valence of saccharin solution consumption from the rewarding property, the aversive property induced by morphine's conditioning, and the neutral states via saccharin extinction processes after morphine's conditioning.

Methods

All rats received virus infection, buried optical fiber, optical stimulation, water deprivation, and saccharin solution consumption phases. In Experiment 1, rats were given ChR2 virus infection into the cingulate cortex (Cg1), prelimbic cortex (PrL), and infralimbic cortex (IL) to influence the rewarding saccharin solution consumption under photostimulation. In Experiment 2, rats were given ChR2 or EYFP virus infection into the Cg1, PrL, and IL to alter the saccharin solution consumption in the morphine-induced aversively conditioned taste aversion (CTA) and the saccharin solution consumption in the neutral state following the extinction process under photostimulation. Later, the immunohistochemical staining with c-Fos protein was performed for the Cg1, IL, PrL, nucleus accumbens core, nucleus accumbens shell, central amygdala, basolateral amygdala, ventral tegmental area, and dentate gyrus.

Results

The results showed that optogenetic PrL stimulation decreased the rewarding valence of saccharin solution consumption and increased the morphine-induced, aversive valence of saccharin solution consumption. PrL stimulation decreased the neutral valence of saccharin solution consumption via the extinction process. Cg1 optogenetic stimulation increased the rewarding valence of saccharin solution consumption and the aversive valence of saccharin solution consumption induced by morphine in conditioning. Optogenetic IL stimulation increased the aversive valence of saccharin solution consumption induced by morphine via conditioning.

Conclusion

Altogether, optogenetic stimulation in the subareas of the mPFC modulated the reward, aversion, and neutral valences of the stimulus and altered neuronal activity in the mPFC, amygdala, nucleus accumbens, and hippocampus. Notably, the change of valence was temporary alternation during light-on related to the light-off periods. However, the findings may provide insights in the development of novel treatments for addictive symptoms.

Upregulation of Haploinsufficient Gene Expression in the Brain by Targeting a Long Non-coding RNA Improves Seizure Phenotype in a Model of Dravet Syndrome

Dravet syndrome is a devastating genetic brain disorder caused by heterozygous loss-of-function mutation in the voltage-gated sodium channel gene SCN1A. There are currently no treatments, but the upregulation of SCN1A healthy allele represents an appealing therapeutic strategy. In this study we identified a novel, evolutionary conserved mechanism controlling the expression of SCN1A that is mediated by an antisense non-coding RNA (SCN1ANAT). Using oligonucleotide-based compounds (AntagoNATs) targeting SCN1ANAT we were able to induce specific upregulation of SCN1A both in vitro and in vivo, in the brain of Dravet knock-in mouse model and a non-human primate. AntagoNAT-mediated upregulation of Scn1a in postnatal Dravet mice led to significant improvements in seizure phenotype and excitability of hippocampal interneurons. These results further elucidate the pathophysiology of Dravet syndrome and outline a possible new approach for the treatment of this and other genetic disorders with similar etiology.

Can iterative reconstruction improve imaging quality for lower radiation CT perfusion? Initial experience

BACKGROUND AND PURPOSE

Initial results using IR for CT of the head showed satisfactory subjective and objective imaging quality with a 20-40% radiation dose reduction. The aim of our study was to compare the influence of IR and FBP algorithms on perfusion parameters at standard and lowered doses of CTP.

MATERIALS AND METHODS

Forty patients with unilateral carotid stenosis post-carotid stent placement referred for follow-up CTP were divided into 2 groups (tube currents were 100 mAs in group A and 80 mAs in group B). Datasets were reconstructed with IR and FBP algorithms; and SNRs of gray matter, white matter, and arterial and venous ROIs were compared. CBF, CBV, and MTT means and SNRs were evaluated by using linear regression, and qualitative imaging scores were compared across the 2 algorithms.

RESULTS

The mean effective radiation dose of group B (2.06 mSv) was approximately 20% lower than that of group A (2.56 mSv). SNRs for ROIs in the dynamic contrast-enhanced images were significantly higher than those for the FBP images. Correlations of the SNRs for CBF, CBV, and MTT across the 2 algorithms were moderate (R² = 0.46, 0.23, and 0.44, respectively). ROIs in gray matter rather than the IR algorithm predicted increasing SNRs in all CBF, CBV, and MTT maps. Two cases of significant restenosis were confirmed in both algorithms. CBV, CBF, and MTT imaging scores did not differ significantly across algorithms or groups.

CONCLUSIONS

Lower dose CTP (20% below normal dose) without IR can effectively identify oligemic tissue in poststenting follow-up. IR does not alter the absolute values or increase the SNRs of perfusion parameters. Other methods should be attempted to improve SNRs in settings with low tube currents.

Monitoring peri-therapeutic cerebral circulation time: a feasibility study using color-coded quantitative DSA in patients with steno-occlusive arterial disease

BACKGROUND AND PURPOSE

Intracranial hemodynamics are important for management of SOAD. This study aimed to monitor peri-stent placement intracranial CirT of patients with SOAD.

MATERIALS AND METHODS

Twenty-five patients received stent placement for extracranial ICA stenosis, and 34 patients with normal CirT were recruited as controls. Their color-coded DSAs were used to define the Tmax of selected intravascular ROI. A total of 20 ROIs of the ICA, OphA, ACA, MCA, FV, PV, OV, SSS, SS, IJV, and MCV were selected. rTmax was defined as the Tmax at the selected region of interest minus Tmax at the cervical segment of the ICA (I1 on AP view and IA on lateral view). rTmax of the PV was defined as intracranial CirT. Intergroup and intragroup longitudinal comparisons of rTmax were performed.

RESULTS

rTmax values of the normal cohorts were as follows: ICA-AP, 0.12; ICA-LAT, 0.10; A1, 0.28; A2, 0.53; A3, 0.81; M1, 0.40; M2, 0.80; M3, 0.95; OphA, 0.35; FV, 4.83; PV, 5.11; OV, 5.17; SSS, 6.16; SS, 6.51; IJV, 6.81; and MCV, 3.86 seconds. Before stent placement, the rTmax values of arterial ROIs, except A3 and M3, were prolonged compared with values from control subjects (P < .05). None of the rTmax of any venous ROIs in the stenotic group was prolonged with significance. After stent placement, the rTmax of all arterial ROIs shortened significantly, except A1and M3. Poststenting rTmax was not different from the control group.

CONCLUSIONS

Without extra contrast medium and radiation dosages, color-coded quantitative DSA enables real-time monitoring of peri-therapeutic intracranial CirT in patients with SOAD .

Study on cement mortar and concrete made with sewage sludge ash

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

Viscoelastic thin polymer films under transient residual stresses: two-stage dewetting on soft substrates

A nonmonotonic, two-stage dewetting behavior was observed for spin coated thin viscoelastic polymer films on soft elastic substrates. At times shorter than the relaxation time of the polymer (t<tau_{rep}), dewetting generated deep trenches in the soft rubbery substrate which, in turn, almost stopped dewetting. At later stages (t>>tau_{rep}), dewetting accelerated, accompanied by an unstable rim. However, holes nucleated at t<tau_{rep} showed only this second-stage behavior. Our observations are attributed to large elastic deformations in the substrate caused by transient residual stresses within the film.

Bilateral traumatic carotid-cavernous fistulae: Strategies for endovascular treatment

BACKGROUND

Most traumatic carotid-cavernous fistula/e (TCCF) are unilateral, and simultaneous bilateral TCCF are uncommon. The purpose of this study was to evaluate the angiographic architecture of bilateral TCCF and report our experience with their endovascular management.

METHOD

Over 15 years, 252 consecutive patients with TCCF were referred to our institute for endovascular treatment. Bilateral TCCF occurred in 5 men and 2 women with a mean age of 31 years. The angiographic architectures of bilateral TCCF were evaluated with cerebral angiography. All patients underwent a single session of transarterial embolisation by using various permanent embolic materials and were followed up clinically or with angiography for a mean of 22 months (range 9-36 months).

FINDINGS

All patients presented with neuro-ophthalmic symptoms and signs. No new instances of cerebrovascular ischemia or intracranial haematoma resulted from bilateral TCCF. All fistulae were associated with partial arterial steal and were successfully occluded by using a detachable balloon and/or a detachable coil with or without a liquid adhesive. Of 14 TCCF, 9 were completely obliterated with preserved flow of the internal carotid artery (ICA). In the other 5 fistulae, the ICA had to be sacrificed to achieve occlusion because the anatomy of the fistula was complex. All fistula related symptoms resolved immediately or gradually during clinical follow up. No clinically significant procedure related neurological complications or recurrent fistulae were observed.

CONCLUSIONS

All bilateral TCCF were associated with a partial arterial steal phenomenon. Single session endovascular treatment using various embolic materials was effective in managing these high-flow fistulae. In all patients, it was possible to preserve one or both ICAs.

Prediction of Alzheimer's disease in mild cognitive impairment: a prospective study in Taiwan

The relationship between apolipoprotein E (ApoE) and clinical manifestations of mild cognitive impairment (MCI) has not been investigated in non-Caucasian populations. This prospective study was conducted in an ethnic Chinese population to evaluate the correlations of ApoE genotype, cognitive performance, medial temporal structure volumes, and clinical outcome in amnestic MCI. Twenty normal elders, 58 MCI, and 20 mild Alzheimer's disease (AD) patients received neuropsychological, MRI, and ApoE genotype assessments at baseline. Patients with MCI had intermediate cognitive performance and hippocampal volumes between those in normal and AD groups. In each diagnostic group, epsilon4 carriers (E4+) consistently had smaller hippocampal volume than non-carriers (E4-) did. Nineteen MCI subjects (32.7%) converted to AD during the 3-year study period. Compared with MCI non-converters and E4- MCI converters, E4+ MCI converters had the smallest hippocampal volume. However, epsilon4 was not a predictor for AD. Both cognitive performance and hippocampal volume were predictive for progression to AD. However, stepwise Cox regression model integrating both neuropsychological and radiological variables showed that global cognitive performance was the only significant predictor for AD. A poor global cognitive score may be more crucial than a small hippocampal volume in the prediction of AD.

Percutaneous vertebroplasty for patients with osteoporosis: a one-year follow-up

PURPOSE

To evaluate changes in height and wedge angle of treated vertebral bodies and kyphosis angle 1 year after vertebroplasty.

MATERIAL AND METHODS

We reviewed radiographs of 95 vertebral bodies treated with vertebroplasty in 60 patients with osteoporosis. Only vertebral bodies with imaging evidence of a new fracture or avascular necrosis received vertebroplasty. Images were obtained for evaluation before vertebroplasty (B), within 2 weeks after vertebroplasty (T), and after 1 year (T1).

RESULTS

The mean wedge angle decreased by 5.4 degrees from B to T1. Mean of the anterior, central, and posterior heights of the fractured bodies increased by 12.6%, 9.6%, and 3.1%, respectively, from B to T1. The kyphosis angle improved by 3.2 degrees initially from B to T, but the improvement later disappeared. In 48% of these patients, a new fracture developed after vertebroplasty, and 63% of the fractures were adjacent to a vertebroplasty-treated vertebral body.

CONCLUSION

The increase in height and wedge angle of the vertebral bodies generally lasted at least 1 year. Improvement in kyphosis angles was lost 1 year after vertebroplasty because new fractures occurred in 48% of these patients. Prevention of new fractures after vertebroplasty remains an important task.

Carotid blowout treated by direct percutaneous puncture of internal carotid artery with temporary balloon occlusion

SUMMARY

Direct percutaneous puncture of a cervical carotid pseudoaneurysm for coil placement or acrylic embolization is described for the endovascular management of acute carotid blowout. However, direct puncture of the internal carotid artery (ICA) for the endovascular management of carotid blowout has not been described. We report a difficult case of acute carotid blowout syndrome in a patient who had radiation- induced occlusion of the right common carotid artery with vasculopathy and pseudoaneurysm in the right cervical ICA. Collaterals from the branches of the controlateral external carotid artery (ECA) anastomosed with branches of right ECA supplied the vasculopathy. We performed direct percutaneous puncture of the bulb of the right ICA using a spinal needle and placed fiber coils to occlude antegrade flow of the artery. During the injection of a mixture of N-butyl cyanoacrylate and lipiodol oil for embolization of the remaining carotid bulb, we transiently inflated an occlusion balloon in the controlateral common carotid artery to further arrest antegrade flow in the ICA. The vasculopathy and pseudoaneurysm of the right cervical ICA were successfully embolized, with preservation of the distal branches of the right ICA.

Neuroradiological findings in atypical teratoid/rhabdoid tumor of the central nervous system

PURPOSE

To evaluate the computed tomography (CT) and magnetic resonance imaging (MRI) findings of atypical teratoid tumor/rhabdoid tumor (AT/RT) of the central nervous system (CNS).

MATERIAL AND METHODS

Twenty cases of CNS AT/RT have been found over the past 23 years in our hospital; these involving 11 boys and 9 girls whose mean age at diagnosis was 5.5 years. Their clinical data, the CT, and MRI findings were reviewed retrospectively.

RESULTS

AT/RT was located in the cerebellum in 15 cases. Four cases arose from the supratentorial region, while only one occurred primarily in the lumbar spinal cord. Almost all cases revealed heterogeneous intensity and heterogeneous enhancement. Peripheral cystic components were common. Survival time ranged from 2 months to 3 years, with a mean survival of 11.6 months.

CONCLUSION

Most cases of AT/RT are located in the cerebellum. The radiologic manifestations are non-specific. The diagnosis mainly depends on the pathologic findings. However, AT/RT should still remain in the differential diagnosis of brain tumors in young children, especially those located in the cerebellar hemisphere and with eccentric cysts.

Two novel mutations of the glycine receptor gene in a Taiwanese hyperekplexia family

The authors report a Taiwanese family with autosomal recessive hyperekplexia. Two novel mutations, W96C (from the paternal allele) and R344X (from the maternal allele), which are located in exon 4 and exon 7 of the GLRA1 gene, were identified in this family. A series of electrophysiologic investigations were conducted in one of the probands, and the results suggest that the "startle center" is located subcortically.

Environmental risk factors of young onset Parkinson's disease: a case-control study

While the cause of Parkinson's disease (PD) remains unknown, recent evidence suggests certain environmental factors, such as well water drinking, herbicides and pesticides exposure, and neurotoxins, may trigger the chain of oxidative reactions culminating in the death of dopaminergic neurons in substantia nigra to cause parkinsonism. Most studies to date focused on PD with old age onset. However, there is a peculiar group of parkinsonian patients, the young onset Parkinson's disease (YOPD), in whom the age of onset is before 40. It is intriguing to know whether earlier exposure to the putative neurotoxin(s) may contribute to the earlier onset. We therefore conducted this case-control study in which 60 PD patients, 30 YOPD patients and the same number of age- and sex-matched young controls were included. Using logistic regression, we found well water drinking and head injury were risk factors for the development of YOPD. When YOPD patients were compared with PD, we found head injury and exercise were the significant predictors. Keeping all other variables constant, head injury was a risk factor and exercise appeared to be a protective factor. We conclude early exposure to well water drinking and head trauma may trigger and expedite the appearance of parkinsonian features, but such acceleration may be prevented through regular exercise.

Correlation of gas chromatographic properties of chlorobenzenes and polychlorinated biphenyls with the occurrence of reductive dechlorination by untamed microorganisms

To understand the dechlorination ability of chlorobenzenes (CBs) and polychlorinated biphenyls (PCBs) by untamed microorganisms under anaerobic condition and to correlate gas chromatographic properties with the occurrence of reductive dechlorination, introduction of CBs and PCBs in the culture medium inoculated with microorganisms from sludge and sediment, respectively, were performed. Three kinds of culture media preparing from sludge, river water and a synthetic medium were used in the experiments. HCB was degraded to 1,3,5-trichlorobenzene (1,3,5-TCB) and 1,3-dichlorobenzene (1,3-DCB) in both sludge medium and synthetic medium with inoculated microorganisms. Three PCB congeners including 2,3,4-, 3,4,5- and 2,3,4,5-CBp (chlorinated biphenyl) were not found to be dechlorinated in the river water medium with inoculation culture but to be dechlorinated in the synthetic medium. MNDO methodology was used to compute theoretical dechlorination reaction heats and GC-ECD techniques were used to estimate chromatographic data of CB and PCB congeners. Both CB and PCB congeners showed that dechlorination by untamed microorganisms under anaerobic mixed cultures were more likely to occur when larger amounts of energy were released and greater deltaln RRT value between the parent congener and the daughter product was observed. Deltaln RRT provided a more precise information on the singularity of PCBs ortho-dechlorination in an aspect of thermodynamic favorable rule.

Corticotropin-releasing hormone (CRH) as a regulator of waking

Corticotropin-releasing hormone (CRH), expressed in widely distributed regions of the central nervous system (CNS), mediates the hypothalamic-pituitary-adrenal (HPA) axis and autonomic components of responses to stressors. Sleep, a fundamental CNS process, is altered in response to a variety of stressors. Although there is an extensive literature on the role of CRH in responses to stressors, there is relatively little information on the role of CRH in normal, spontaneous behavior. We hypothesize that CRH is involved in the regulation of waking in the absence of overt stressors. Some of the early evidence supporting this hypothesis was indirect. We summarize in this review studies from our laboratory and others that provide direct evidence that CRH is involved in the regulation of spontaneous waking. We also suggest on the basis of recent studies that some effects of CRH on waking and sleep may be mediated by actions within the CNS of the immunomodulatory cytokine interleukin (IL)-1. Collectively, these observations suggest that CRH contributes to the regulation of spontaneous waking in the absence of stressors, and also indicate a potential mechanism mediating complex alterations in sleep that occur in response to immune challenge.

Rag-1 mutations associated with B-cell-negative scid dissociate the nicking and transesterification steps of V(D)J recombination

Some patients with B-cell-negative severe combined immune deficiency (SCID) carry mutations in RAG-1 or RAG-2 that impair V(D)J recombination. Two recessive RAG-1 mutations responsible for B-cell-negative SCID, R621H and E719K, impair V(D)J recombination without affecting formation of single-site recombination signal sequence complexes, specific DNA contacts, or perturbation of DNA structure at the heptamer-coding junction. The E719K mutation impairs DNA cleavage by the RAG complex, with a greater effect on nicking than on transesterification; a conservative glutamine substitution exhibits a similar effect. When cysteine is substituted for E719, RAG-1 activity is enhanced in Mn(2+) but remains impaired in Mg(2+), suggesting an interaction between this residue and an essential metal ion. The R621H mutation partially impairs nicking, with little effect on transesterification. The residual nicking activity of the R621H mutant is reduced at least 10-fold upon a change from pH 7.0 to pH 8.4. Site-specific nicking is severely impaired by an alanine substitution at R621 but is spared by substitution with lysine. These observations are consistent with involvement of a positively charged residue at position 621 in the nicking step of the RAG-mediated cleavage reaction. Our data provide a mechanistic explanation for one form of hereditary SCID. Moreover, while RAG-1 is directly involved in catalysis of both nicking and transesterification, our observations indicate that these two steps have distinct catalytic requirements.

Magnetic resonance imaging appearance of intradural spinal lipoma

Intradural spinal lipoma not associated with spinal dysraphism is a rare tumor often presenting with nonspecific symptoms and indolent clinical course. Its intradural location and fat component is the key for proper preoperative diagnosis, which could hardly be made by traditional imaging studies including plain film and myelography. Both CT and MRI can reveal the fat component of the tumor, but MRI is superior to CT in demonstrating its relationship with adjacent normal nerve tissue. We report a 32-year-old man who had back pain for years and the symptom progressed rapidly in recent two months. MRI revealed an intradural tumor at T12 level with high signal intensity on both T1- and T2-weighted images. The signal intensity dropped dramatically with fat saturation technique, which confirmed fat as its main component. The patient received surgery and the tumor was proved to be an intraspinal lipoma.

Comparisons of PCBs dechlorination occurrences in various contaminated sediments

A comparison was made of reductive dechlorination occurrences of polychlorinated biphenyls (PCBs) by microorganisms collected from contaminated sediments including Er-Jen River (Tainan, Taiwan), Hudson River (Ft. Edward, NY), Silver Lake (Pittsfield, MA) and Puget Sound (Washington State). Comparisons was made in terms of chromatographic data (referring to the biological activity, including microbial availability) and thermodynamic data (demonstrating the selectivity of anaerobic microorganisms in the dechlorination of chlorinated compounds). Chromatographic data was established in terms of difference in relative retention time (delta ln RRT) and thermodynamic data was estimated as heat of reaction (delta H(r)0). Both were calculated and correlated to occurrences of dechlorination reactions. Observed dechlorination reactions for individually introducing PCB congener had delta ln RRT levels measured as >0.47 (Er-Jen River), >0.29 (Hudson River), >0.36 (Silver Lake) and >0.45 (Puget Sound, for Aroclor 1254 dechlorination). Critical of delta H(r)0 and delta ln RRT values showed that Hudson River and Silver Lake microorganisms were capable of dechlorinating PCBs through reactions with larger H(r)0 value (lower levels of released energy) and smaller delta ln RRT value compared with those found in Er-Jen River and Puget Sound sediments. Differences in the critical delta ln RRT values of these sediments may be due to differences in their levels of PCB contamination.

Sequential MR studies of a patient with white matter disease presenting psychotic symptoms: ADEM versus single-episode MS

Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) are both demyelinating white matter disorders. It is difficult to differentiate ADEM from single episode MS because of the similar clinical presentation, cerebral spinal fluid (CSF) analysis, histological finding and magnetic resonance image (MRI) appearance. We report an ADEM case with unusual clinical presentations of predominant psychiatric symptoms, and relatively long disease course. Initially, we were not able to distinguish it from single episode MS. By means of sequential MR images followed up 2 years and spectroscopy studies, and the dramatic clinical improvement after corticosteroid therapy, ADEM was diagnosed as the disease entity of this patient. In this case report we will present the MR findings of this patient and discuss the differentiation between the ADEM and MS.

Image evaluation of suprazygomatic masticator space lesions

In order to understand lesions involving the suprazygomatic masticator space (SZMS) demonstrated on computered tomography (CT) or magnetic resonance (MR) images, we collected 45 cases of lesions in SZMS. There were hematomas in 26 cases, tumors in 16 cases, and abscesses in 3 cases. The location of these lesions in compartments of the SZMS and adjacent structures was analyzed. Most commonly hematoma was found in the deep loose connective tissue (80.8%), followed by the superficial dense connective tissue (61.5%). Only 2 SZMS hematoma involved the superficial fat pad. Five patients had air accumulation in the SZMS, and all were in the deep fat pad and with maxillary sinus fracture. Of the sixteen cases which were tumors, 12 were extended from adjacent structures, and four were primary tumor. In cases of tumor, compartments of SZMS involved most frequently were temporal muscles (15 of 16 cases), followed by deep fat pad (8 of 16 cases). The connective tissue layer of SZMS is a communication pathway for superficial spread of infection, hematoma, or tumor invasion to or from the scalp and face. Compartments of deep fat pad and temporal muscle are also pathways for the spread of disease to or from the face, intracranium and orbit. The primary tumors in infratemporal fossa and SZMS are rare. Malignant tumors in SZMS usually come from surrounding spaces.

Percutaneous transluminal angioplasty as an adjunct to treat the carotid-cavernous fistula

We report a case of the direct carotid-cavernous fistula (CCF) with high-grade stenosis of the internal carotid artery (ICA) and treatment via the transarterial route after percutaneous transluminal angioplasty (PTA). A 46-year-old man was found to have a CCF after a motorcycle accident. Transarterial embolization was attempted, but it failed due to stenosis of the left cervical ICA. After the procedure of PTA for dilatation of the stenotic ICA, the fistula was successfully obliterated by detachable balloon subsequently. There were no complications or recurrence of the fistula at the three-year clinical follow up.

Endovascular embolization of carotid-cavernous fistula using the posterior communicating artery approach: a case report

We report a case of direct carotid-cavernous fistula complicated with occlusion of internal carotid artery (ICA) at attempted endovascular obliteration via ICA and subsequent successful embolization via the posterior communicating artery (PCoA) approach. After a thorough understanding of vascular anatomical alterations associated with initial technical failure with detachable balloons, a microcatheter was navigated to the fistula site via the vertebro-basilar-PCoA to the distal cavernous segment of the left ICA. Embolization of the fistula was performed with deposition of three platinum microcoils. Angiograms after embolization showed complete disappearance of the fistula. There was no procedural complication and no recurrence of fistula at one-year clinical follow up.

Pneumocephalus secondary to septic thrombosis of the superior sagittal sinus: report of a case

Pneumocephalus secondary to septic superior sagittal sinus thrombosis (SSSST) is extremely rare. We report computed tomography (CT) findings in a 63-year-old man with SSSST caused by the gas-forming organism Klebsiella pneumoniae. The patient presented with fever, chills, general weakness, and spontaneous progressive swelling of the right frontoparietal scalp. CT revealed a gas-containing abscess over the right frontoparietal subgaleal region and in the superior sagittal sinus. Surgical drainage of the subgaleal abscess was performed and blood and pus cultures grew Klebsiella pneumoniae. The patient died of sepsis on the 6th day of hospitalization.

Inadvertent knotting of a thoracic epidural catheter

We report a case of corrosive injury of upper gastrointestinal and respiratory tracts scheduled for feeding jejunostomy under thoracic epidural anesthesia. An epidural catheter was inserted at the T8-T9 intervertebral space and threaded 7 cm beyond the tip of the Tuohy needle in a rostral direction. Resistance was noticed during attempts to inject the local anesthetic. As resistance could not be relieved by changing the position of the patient, kinking of the epidural catheter was suspected. Following informing the patient of the associated risks, the catheter was retrieved successfully by gentle and steady pulling. A tight double-knot of catheter was found. No neurological sequelae to the procedure were noticed.

Aneurysms of the fenestrated basilar artery treated with Gulielmi Detachabe Coils: case report

Multiple aneurysms at the site of a basilar artery fenestration (BAF) are extremely rare. We report a case of BAF in association with two aneurysms successfully treated with Guglielmi Detachable Coils (GDCs). A 42-year-old male presented with subarachnoid hemorrhage and consciousness change. Angiograms of the vertebrobasilar artery demonstrated fenestration of the proximal basilar artery associated with two aneurysms. Embolization of aneurysms was done by using GDCs. Aneurysms were almost completely obliterated with preservation of the flow and lumen of the vertebrobasilar system. The patient remains asymptomatic at clinical follow-up of 18 months.

Debt and other influences on career choices among surgical and primary care residents in a community-based hospital system

BACKGROUND

To evaluate debt and other factors that help formulate the career paths of future surgical and primary care physicians, a survey was undertaken.

METHODS

Surgical specialty (SS) and primary care (PC) residents were surveyed regarding demographics, factors influencing choice of specialty, methods of financing education, debt characteristics, and outlooks regarding future earnings and practice characteristics.

RESULTS

The clinical years of medical school and personalities of specialists and residents were important factors in career choices for both PC and SS. The length of residency, desirable lifestyle, and working hours were all more important to PC residents. Surgeons found intellectual challenge and procedure-based practice of greater importance. Although not highly regarded by either group, scholarship obligation and student loans had a significantly greater impact on specialty choice and practice plans for PC residents. At the completion of training, 55% of SS and 28% of PC residents anticipate owing more than $100,000. Debt was especially significant in specialty choice and practice plans for PC residents with debt over $100,000.

CONCLUSION

Surgical residents are less concerned about personal sacrifices in their quest to become surgeons. It appears state funded scholarships are successful in attracting students to primary care. Both SS and PC residents have significant debt, although, SS residents have greater financial debt than primary care residents. However, the anticipation of indebtedness was a more significant factor in determination of career path for PC.

Computed tomography and magnetic resonance imaging characteristics of giant pituitary adenomas

PURPOSE

The purpose of this study was to characterize the computed tomography (CT) and magnetic resonance (MR) imaging features of giant pituitary adenoma (GPA) and to demonstrate the pathways of the spread of GPA.

METHODS

CT and/or MR imaging scans of 356 patients evaluated preoperatively for single pituitary tumor were reviewed. Fourteen tumors (4%) fulfilled the radiologic criteria for GPA. There were 10 male and four female patients, ranging in age from 22 to 71 years (mean, 52 yr). We retrospectively reviewed the CT and MR imaging scans of these patients to characterize tumor appearances and identify the pathways of tumor extension.

RESULTS

Thirteen tumors (93%) extended upward to the suprasellar cistern, and/or hypothalamus and third ventricle. Infrasellar extension through the sellar floor and sphenoid sinus to the skull base, or to the ethmoid sinus or the nasopharynx, was identified in seven patients (50%). Eight patients (57%) had lateral invasion to the cavernous sinus. Temporal and frontal extension was apparent in seven patients (50%) and six patients (43%), respectively. Five patients (36%) had posterior subtentorial extension to the posterior fossa. Histologically, only two GPAs showed invasive features. There was no correlation among histologic features, pituitary hormone concentrations, and evidence of tumor aggressiveness on CT and MRI scans.

CONCLUSIONS

GPA has the potential for widespread, multi-directional extension. Our results indicate that any type of pituitary adenoma, regardless of its endocrinologic activity, may invade surrounding structures. Suprasellar invasion is the most common pathway of tumor spread, followed by infrasellar, lateral, anterior, and posterior routes.

Breech deformation complex in neonates

OBJECTIVE

To demonstrate the association of minor anomalies and breech-presenting newborns with breech deformation complex.

STUDY DESIGN

A total of 3,345 newborns with singleton, term delivery were examined based on a list of 67 items of major and minor anomalies. All infants were divided into two groups: group 1, vertex presentation (3,107 infants); group 2, breech presentation (224 infants). The prevalence of anomalies between both groups was compared.

RESULTS

There were 1,495 (44.9%) infants with one or more minor anomalies, which included 1,313 infants (42.3%) in group 1 and 182 (81.3%) in group 2 (P < .005). The prevalence of anomalies in groups 1 and 2 were: frontal bossing (1.8% vs. 51%), prominent occiput (0.8% vs. 42%), upward slant (11.6% vs. 23.7%) and low-set ears (0.3% vs. 20.5%). Torticollis (0.3% vs. 1.78%) and congenital dislocation of the hip (CDH) (0.06% vs. 0.9%) (all P < .005) were related to breech presentation.

CONCLUSION

Breech-presenting newborns had a higher risk of combining breech deformation complex, torticollis and CDH. The criteria for breech deformation complex included frontal bossing, prominent occiput, upward slant and low-set ears. The prevalence of breech deformation complex, torticollis and CDH was not related to the delivery method.

"Paper-clip" type triple helix formation by 5'-d-(TC)3Ta(CT)3Cb(AG)3 (a and b = 0-4) as a function of loop size with and without the pseudoisocytosine base in the Hoogsteen strand

The formation of a DNA "paper-clip" type triple helix (triplex) with a common sequence 5'-d-(TC)(3)T(a)()(CT)(3)C(b)()(AG)(3) (a and b = 0-4) was studied by UV thermal melting experiments and CD spectra. These DNA oligomers form triplexes and duplexes under slightly acidic and neutral conditions, respectively. The stability of the formed triplexes (at pH 4.5) or duplexes (at pH 7.0 or 8.0) does not vary significantly with the size of the loops (a and b = 1-4). At pH 6.0, the triplex stability is, however, a function of a and b. It is also interesting to note that the oligomer 5'-d-(TC)(3)(CT)(3)(AG)(3) (a and b = 0) forms a stable triplex at pH 4.5 with a slightly lower T(m) value, due to dissociation of a base triad at one end and a distorted base triad at the other, observed by (1)H NMR. Thus, we have here a model system, 5'-d-(TC)(3)T(a)(CT)(3)C(b)(AG)(3), that could form a triplex effectively with (a and b = 1-4) and without (a and b = 0) loops under acidic conditions. In addition, the triplex formation of oligomers with replacement of one, two, or three 2'-deoxycytidine in the Hoogsteen strand by either 2'-deoxypseudoisocytidine (D) or 2'-O-methylpseudoisocytidine (M) was also studied in the sequence 5'-d-(TX)(3)T(2)(CT)(3)C(2)(AG)(3) (where X is C, D, or M). Both CD spectra and UV melting results showed that only D3 [(TX)(3) = (TD)(3)] and M3 [(TX)(3) = (TM)(3)] were able to form the paper-clip structure under both neutral and acidic conditions. This is because the N(3)H of a pseudoisocytosine base can serve as a proton donor without protonation. We hereby proved that the 2'-deoxypseudoisocytidine, similar to 2'-O-methylpseudoisocytidine, could replace 2'-deoxycytidine in the Hoogsteen strand to provide triplex formation at neutral pH.

Double-balloon technique for embolization of carotid cavernous fistulas

Embolization of a carotid cavernous fistula (CCF) by means of a detachable balloon is an established method for treating CCFs while preserving a patent parent internal carotid artery (ICA). However, failure to embolize the CCF may occur on a few occasions, such as when the balloon cannot pass through the fistula into the cavernous sinus by blood flow, or when the inflated balloon in the cavernous sinus retracts to the carotid artery. Under these circumstances, the ICA may have to be sacrificed in order to treat the CCF. Herein we describe a double-balloon technique for embolization of a CCF. By applying this technique, we successfully treated nine of 11 CCFs, without compromise of the parent ICA when the conventional one-balloon technique failed.

Accuracy of sonography in predicting the outcome of fetal congenital diaphragmatic hernia

BACKGROUND

The outcome of congenital diaphragmatic hernia (CDH) remains poor despite recent advances in neonatal care. This study was designed to evaluate the role of sonography in predicting the outcome of CDH.

METHODS

Pregnancies with CDH were studied. Fetal survival, morbidity, combined anomalies and mortality were recorded. Seven parameters were recorded, including the presence of hydramnios, side of herniation, cardiac deviation, stomach presence, gestational age at the time of finding the CDH and time of postpartum herniorrhaphy. The predictive values of these parameters for fetal outcome were analyzed.

RESULTS

A total of 31 pregnancies were studied. There were 11 cases (35.5%) of termination, seven cases (22.6%) of perinatal death, four cases (12.9%) of late death and nine cases of survival (29%). The survivor group included four cases (44.4%) of complete recovery and five cases (55.6%) with persistent morbidity. There were 15 cases of simple CDH including eight cases of cardiac anomalies (ventricular-septal defect, atrial-septal defect, patent ductus arteriosus and ventricular dilatation). There were eight cases with severe anomalies (3 with trisomy 18, 2 with Cantrell's pentalogy, 1 with trisomy 13, 1 with cystic hygroma and one with Tetralogy Fallot). Among the seven parameters studied, gestational age at the time of finding the CDH and hydramnios were related to fetal survival.

CONCLUSIONS

Sonography assists in predicting the postnatal outcome of CDH. Diagnosis of CDH at less than 25 weeks' gestation and the existence of hydramnios are associated with higher mortality. Postnatal therapy and prenatal surgical intervention are necessary to salvage fetuses in the presence of these two situations. The survival rate of infants with CDH was 45%. Of these, 55.6% had persistent morbidity. Prenatal counseling should reflect this.

Salvage surgery for recurrent nasopharyngeal carcinoma

OBJECTIVE

To evaluate the efficacy of salvage surgery in the treatment of recurrent nasopharyngeal carcinoma (NPC) at the primary site.

STUDY DESIGN

A retrospective investigation of the outcome of salvage surgery for 28 patients with recurrent NPC after definite radiation therapy.

METHODS

The nasopharynx was approached anteroposteriorly by the transmaxillary approach (maxillary swing, maxillectomy) or inferior approach (midline mandibulotomy or median labiomandibular glossotomy), or laterally by modified facial translocation or transpterygoid approach; intentional ligation of the internal carotid artery was performed after establishment of extracranial-intracranial (EC-IC) bypass in one patient; postoperative irradiation was given to the patients with positive pathological margins.

RESULTS

Nine patients lived without disease for 20 to 93 months (mean interval, 52 mo) after surgery; among them, eight patients had T1 tumors that were resected totally by surgery via anteroposterior approaches and the other patient had postoperative irradiation to control the disease. Seven patients had local recurrence 8 to 21 months after treatment. Four patients developed distant metastases, including one patient with a T2b tumor that was totally resected through modified facial translocation approach with ligation of internal carotid artery. Eight patients died of other causes; internal carotid artery blowout was the cause of death in four of these eight patients.

CONCLUSIONS

In most cases of recurrence, T1 nasopharyngeal tumors can be resected totally by anteroposterior approaches; for T2 or larger tumors, postoperative irradiation is usually necessary. Otherwise, facial translocation offers a better chance to completely resect the tumors. Internal carotid artery is better ligated if patients have received greater than 70 Gy irradiation or if the artery must be exposed during the surgery. We suggest that EC-IC bypass be used to avoid the possible complications (or cerebral ischemic stroke) caused by ligation of internal carotid artery. The transmaxillary approach is favored in the management of nasopharyngeal tumor recurrence with nasal cavity extension, and midline mandibulotomy is more suitable for resection of posterior margin of nasopharyngeal tumor recurrence. Facial translocation offers the widest operative field and is the most versatile approach for radical resection of nasopharyngeal tumor recurrence, but the surgeon should be skilled in the management of the facial nerves to reduce morbidity.

IL-1 is a mediator of increases in slow-wave sleep induced by CRH receptor blockade

We hypothesize that corticotropin-releasing hormone (CRH), a regulator of the hypothalamic-pituitary-adrenal (HPA) axis, is involved in sleep-wake regulation on the basis of observations that the CRH receptor antagonist astressin, after a delay of several hours, reduces waking and increases slow-wave sleep (SWS) in rats. This delay suggests a cascade of events that begins with the HPA axis and culminates with actions on sleep regulatory systems in the central nervous system. One candidate mediator in the brain for these actions is interleukin (IL)-1. IL-1 promotes sleep, and glucocorticoids inhibit IL-1 synthesis. In this study, central administration of 12.5 microgram astressin into rats before dark onset reduced corticosterone 4 h after injection and increased mRNA expression for IL-1alpha and IL-1beta but not for IL-6 or tumor necrosis factor-alpha in the brain 6 h after injection. To determine directly whether IL-1 is involved in astressin-induced alterations in sleep-wake behavior, we then pretreated rats with 20 microgram anti-IL-1beta antibodies before injecting astressin. The increase in SWS and the reduction in waking that occur after astressin are abolished when animals are pretreated with anti-IL-1beta. These data indicate that IL-1 is a mediator of astressin-induced alterations in sleep-wake behavior.

Routine blastocyst culture and transfer: 201 patients' experience

PURPOSE

The purpose was to compare the outcomes between day-5 blastocyst and day-2 embryo transfers.

METHODS

Infertile women who accepted the ovarian hyperstimulation and oocyte retrieval were divided: Group 1, day 2 embryo transfer, group 2, cultured to day 5 in serum-free sequential culture medium and transfer. Early embryo quality and growth, blastocyst formation and quality, implantation rate (IR) and pregnancy rates (PR) were detected.

RESULTS

Total blastocyst formation rate was 49.4%. Better early embryo quality (days 2, 3) and higher day 3 blastomere number possess higher blastocyst formation rate. The IR for day 2 and day 5 embryos were 10.8% and 22.2%, respectively. The PR in both groups were comparable (37.3% vs. 41.8%).

CONCLUSIONS

Blastocyst transfer has higher IR and comparable PR as those of day 2 embryo transfer. Early embryo qualities and day 3 blastomere number are useful in predicting the final blastocyst formation. Blastocyst formation rate is not related to maternal age, infertile causes, insemination methods, and early embryo number.

Gender prevalence in twin-twin transfusion syndrome

BACKGROUND

This study aimed to determine the gender prevalence of fetuses complicated with twin-twin transfusion syndrome (TTTS).

METHODS

All cases of TTTS corresponded with the following major criteria: a single placenta, monochorion, the same gender, and a combination of polyhydramnios-oligohydramnios. At least one of three minor criteria were required for the establishment of TTTS, including a stuck twin, a birth weight discordance exceeding 20%, and hemoglobin difference > 5 g/dl.

RESULTS

Fifty-six twin pregnancies met the above criteria, of which 33 (58.9%) twin pairs were female. The female tendency existed, but there was a non-significant difference. Mean gestational age at diagnosis was 20.2 +/- 3.2 weeks. The birth weight discordance exceeding 20% was present in 50 of 56 (89.3%), and mean growth discordance was 32% +/- 8%. A stuck twin was noted in 37 of 56 cases (66.1%). The mortality of fetuses or neonates was 34.8% (39/112), including 8 (7.1%) fetal deaths and 31 (27.6%) neonatal deaths. There were no differences in maternal age, parity, or gestational age of delivery between male and female pregnancies.

CONCLUSION

Although the female preponderance did not reach statistical significance, the female tendency might still exist after a larger series analysis. The female tendency may be the result of the gender difference in monochorionic twins. The gender difference could provide research implications and a diagnostic warning for clinicians in monochorionic twin pregnancies before the presence of TTTS.

Doppler evaluation of the uterine and spiral arteries from different sampling sites and phases of the menstrual cycle during controlled ovarian hyperstimulation

OBJECTIVE

To compare the pulsatility index (PI) and resistance index (RI) at different sampling sites of the uterine and spiral arteries in the early and mid-menstrual phases.

MATERIALS AND METHODS

The uterine and spiral arteries of 110 women undergoing similar ovarian hyperstimulation and intra-uterine insemination regimes were examined using transvaginal color Doppler ultrasound. The uterine artery was sampled at five sites: (1) ascending branch; (2) descending branch; (3) proximal, near branch division; (4) mid, 0.5 cm distal to the division; (5) lateral location, 1 cm distal to the division. The spiral artery was sampled at three sites: (a) anterior; (b) fundal; (c) posterior. The uterine and spiral arteries were examined twice, on days 2-3 and 14-16, respectively, of the menstrual cycle. The women were also grouped according to age at examination, < or = 30 years and > 30 years. The PI and RI values for different sites, menstrual phase, and age were compared.

RESULTS

The mean PI and RI values of the uterine artery were: (1) 2.86 +/- 1.20 and 0.92 +/- 0.13; (2) 2.66 +/- 1.15 and 0.89 +/- 0.12; (3) 2.88 +/- 1.26 and 0.90 +/- 0.15; (4) 3.03 +/- 1.02 and 0.91 +/- 0.07; (5) 3.23 +/- 1.38 and 0.89 +/- 0.12; and of the spiral artery were (a) 1.61 +/- 1.01 and 0.69 +/- 0.17; (b) 1.69 +/- 0.74 and 0.74 +/- 0.17; (c) 1.73 +/- 0.86 and 0.68 +/- 0.17. The PI values for uterine and spiral arteries at two phases of the menstrual cycle were 2.92 +/- 1.18 and 1.55 +/- 0.72 (days 2-3); 3.11 +/- 1.15 and 1.80 +/- 1.02 (days 14-16), respectively; for younger women (age < or = 30 years) these values were 2.83 +/- 1.22 and 1.6 +/- 0.85 and for older women (age > 30 years) 3.0 +/- 1.34 and 1.72 +/- 0.96, respectively.

CONCLUSIONS

There were no significant differences in PI and RI values of the uterine and spiral arteries at different sampling sites, phase of the menstrual cycle or age. The higher PI values tended to occur in the lateral uterine artery and posterior spiral artery, during the mid-menstrual phase and in the older age group. The PI and RI values of the mid-uterine and fundal spiral artery sampling sites are representative of the whole uterine artery and spiral artery, respectively.

The identification of an endonuclease that cleaves within an HuR binding site in mRNA

Messenger RNAs (mRNAs) that contain U-rich elements are targeted for rapid decay. Selective inhibition of this decay results in a rapid increase in steady state level. Thus, this is an important regulatory step in gene expression. Previously, we have found that these mRNAs are selectively stabilized by a specific mRNA binding protein called HuR. The mechanism of action of HuR is not well understood. It has been postulated that HuR stabilizes mRNA by the displacement or inhibition of factors that specifically cleave or deadenyl-ate these mRNAs. In this paper, we report the identification and characterization of a novel endo-nuclease that cleaves within an HuR binding site in p27kip1 mRNA. The specificity of this endonuclease and its inhibition by HuR argue for it playing a role in the postranscriptional regulation of gene expression.

Longitudinal survey of fetal ventricular ejection and shortening fraction throughout pregnancy

OBJECTIVES

To assess and compare the ejection fraction (EF) and shortening fraction (SF) of both ventricles through pregnancy.

MATERIALS

Uncomplicated singleton pregnancies, of between 10 and 40 weeks' gestation, were recruited. Transabdominal two-dimensional M-mode imaging of the right ventricular EF (REF), right ventricular SF (RSF), left ventricular EF (LEF), and left ventricular SF (LSF) were performed. Doppler surveys were performed at (1) 10-14 weeks; (2) 15-19 weeks; (3) 20-24 weeks; (4) 25-29 weeks; (5) 30-34 weeks; and (6) 35-40 weeks. The following values were measured: REF, RSF, LEF, LSF, REF/LEF and RSF/LSF.

RESULTS

A total of 42 cases were included. The values of REF, RSF, LEF, and LSF for the six gestational time periods were (1) 0.86, 0.49, 0.85, 0.48; (2) 0.84, 0.48, 0.88, 0.51; (3) 0.76, 0.37, 0.84, 0.48; (4) 0.75, 0.37, 0.84, 0.48; (5) 0.76, 0.38, 0.83, 0.47; and (6) 0.77, 0.38, 0.84, 0.48, respectively. The ratios of REF/LEF and RSF/LSF in each gestational time period were: (1) 1.04, 1.11; (2) 0.95, 0.92; (3) 0.95, 0.90; (4) 0.94, 0.90; (5) 0.94, 0.92; and (6) 0.92, 0.89, respectively.

CONCLUSIONS

After 20 weeks' gestation both the EF and SF of the right ventricle decreased. A non-significant change in the LEF and LSF was observed throughout pregnancy. A decreasing trend in the REF/LEF and RSF/LSF ratios during pregnancy was noted.

Effect of oxidized frying oil and vitamin C levels on the hepatic xenobiotic-metabolizing enzyme system of guinea pigs

The influence of oxidized frying oil (OFO) on the guinea pig hepatic microsomal xenobiotic-metabolizing enzyme system in the presence of different amounts dietary vitamin C was investigated. Weanling male guinea pigs were divided into four groups and were fed 15% oxidized frying oil diets supplemented with vitamin C at 300, 600, or 1,500 mg/kg (experimental diets) or a control diet that contained 15% fresh untreated soybean oil with 300 mg/kg of vitamin C, respectively. After 60 d, guinea pigs were euthanized and phase I and phase II xenobiotic-metabolizing enzymes in the liver were determined. Compared with the fresh oil diet fed the control group, the relative liver weight was higher in the OFO-fed groups. Hepatic microsomal protein and cytochrome P450 contents were significantly higher in OFO-fed guinea pigs than in the control group. Both values increased in response to increased intake of vitamin C. The activities of phase II relative components, including UDP-glucuronyl transferase, UDP-glucuronyl dehydrogenase and beta-glucuronidase, of guinea pigs fed the OFO diets supplemented with 300 mg vitamin C/kg were significantly higher than those of guinea pigs fed the control diet. However, the phase II relative components decreased with increasing vitamin C content in the diet. The results demonstrate that both dietary OFO and vitamin C in guinea pigs induce hepatic xenobiotic-metabolizing enzymes, but the level of induction is modulated by the dietary vitamin C level.

Endovascular embolization of intractable epistaxis

BACKGROUND

We undertook this study to define the role of angiography and endovascular embolization in the treatment of patients with intractable epistaxis.

METHODS

A series of 19 patients with massive intractable epistaxis, all treated with endovascular embolization were reviewed. There were 15 males and four females ranging in age from 18 to 70 years, with a mean age of 38 years. The predisposing factors of intractable epistaxis were head and neck tumors (n = 11), idiopathic symptoms (n = 3), surgical complications (n = 2), arteriovenous malformation of the face (n = 1), thrombocytopenia (n = 1) and trauma (n = 1). Polyvinyl alcohol (PVA) particles and gelfoam plugs were used as embolic agents in 11 patients for devascularization; detachable balloons with N-butyl-2-cyanoacrylate (NBCA) were used in four patients for vascular occlusion; NBCA and/or coils were used in four patients in the carotid and subclavian arteries for obliteration of pseudoaneurysms.

RESULTS

Complete cessation of epistaxis was achieved in all 19 patients immediately after embolization. Seven patients had also undergone surgical tumor removal at two to five days after embolization. Two patients experienced mild to moderate facial pain on the first day after the procedure, but the symptoms later subsided. No significant complication or recurrence was observed in 18 patients. One patient with advanced hypopharyngeal carcinoma died two weeks after embolization due to another episode of massive epistaxis. Clinical follow-up for these patients was 15 days to eight years, with a mean of 41 months.

CONCLUSIONS

Therapeutic endovascular embolization of intractable epistaxis is both efficient and safe. It should be considered as the primary treatment modality in intractable epistaxis.

Imaging of invasiveness of pituitary adenomas

The purpose of our study was to examine the tumor size, imaging invasiveness of the pituitary macroadenomas (PMA) and to evaluate the directions of PMA spread. One hundred and thirty-five patients with PMA were examined with MRI and/or CT for pre-operative evaluation. We retrospectively reviewed the CT and MRI to identify tumor size, extension and to evaluate the directions of tumor spread. One hundred and seventeen patients (87%) had suprasellar extension with compression of optic apparatuses, twelve patients (9%) had extension of tumor upward to hypothalamus and third ventricle. Infrasellar extension via the floor of the sella and sphenoid sinus was found in thirty-eight patients (28%), and further downward extension to ethmoid sinus, nasopharynx and/or skull base was depicted in five patients (4%). Twenty-two patients (16%) had lateral invasion to the cavernous sinus and associated cranial nerves. Temporal and frontal extensions were depicted in seven patients (5%) and six patients (4%), respectively. Five patients (4%) had posterior subtentorial extension to posterior fossa. Histologically, only two patients showed microscopic invasive features. There was no correlation between histologic features and imaging invasiveness. The PMA had the potential of multi-directional extension. This experience indicated any type of pituitary adenoma could invade surrounding structures. Suprasellar invasion was the most common direction of pituitary adenoma spread, followed by infrasellar, lateral, anterior and posterior routes.

Pituitary CRH receptor blockade reduces waking in the rat

We have previously hypothesized that corticotropin-releasing hormone (CRH) is involved in the regulation of physiological waking. Central administration of CRH receptor antagonists reduces spontaneous waking in the rat. Some of the responses to central administration of CRH receptor antagonists may be mediated by mechanisms involving the hypothalamic-pituitary-adrenal axis, either by direct actions on the hypothalamus or by actions at the level of the pituitary due to leakage of the antagonists from the cerebrospinal fluid to blood. To further clarify the role of the hypothalamic-pituitary-adrenal axis as a mediator of responses to CRH receptor blockade, we administered intravenously into freely behaving rats in their home recording cages two specific CRH receptor antagonists, astressin or alpha-helical CRH, and determined subsequent changes in waking and sleep. Our results indicate that both antagonists reduce spontaneous waking, but with different time courses. Astressin, a potent antagonist of pituitary CRH receptors, reduces waking during postinjection hours 9-10, whereas high doses of alpha-helical CRH reduce waking only during the first postinjection hour. These results indicate that some effects of CRH on sleep-wake behavior may be meditated by pituitary CRH receptors.

Haemodynamic effects of chronic tetramethylpyrazine administration on portal hypertensive rats

OBJECTIVE

The purpose of this study was to investigate the therapeutic effects of tetramethylpyrazine, an alkaloid isolated from a Chinese herb Ligusticum wallichii Franch, on portal hypertensive rats.

METHODS

There were three groups of animals: partial portal vein ligated (PVL) rats, bile duct ligated (BDL) rats and sham-operated (Sham) rats. Each rat in every group was given only one of three treatment regimens: tetramethylpyrazine 30 or 50 mg/kg/12 h, or vehicle (0.2 N HCl, 0.7 ml/12 h). There were seven rats allocated to each regimen, with a total of 63 rats studied. Tetramethylpyrazine or vehicle was given via gastric gavage every 12 h for 8 days, starting just after PVL or 3 weeks after BDL, and haemodynamic parameters were measured thereafter.

RESULTS

Both PVL and BDL rats exhibited portal hypertensive and hyperdynamic state as compared with Sham rats. Eight-day tetramethylpyrazine treatment induced dose-dependent reductions of portal venous pressure (PVP), mean arterial pressure (MAP), and total peripheral resistance (TPR) in both PVL and BDL rats. Tetramethylpyrazine at 30 and 50 mg/kg/12 h induced PVP reduction by 10.2 and 16.1% in PVL rats, and 10.5 and 14.8% in BDL rats, respectively, as compared with the vehicle group. There were no significant changes of cardiac index or heart rate (HR) after tetramethylpyrazine treatment in either PVL or BDL rats. In the Sham rats, tetramethylpyrazine did not significantly change PVP, MAP, HR or TPR, despite a tendency of reduction.

CONCLUSION

Our results showed that 8-day treatment of tetramethylpyrazine induced reductions of both portal venous and systemic arterial pressure in portal hypertensive rats with and without cirrhosis. Overall, the therapeutic effects are neither outstandingly efficacious nor altogether beneficial.

Beneficial effects of combined terlipressin and tetramethylpyrazine administration on portal hypertensive rats

The purpose of this study was to investigate the therapeutic effects of terlipressin (TP) alone or in combination with tetramethylpyrazine (TMP) on anesthetized portal hypertensive rats. Portal hypertension was induced by either partial portal vein ligation (PVL, without cirrhosis) or bile duct ligation (BDL, with cirrhosis) in Sprague-Dawley rats. Each PVL or BDL rat received only one of the two regimens: vehicle for 3 min followed by TP (0.017 mg x kg(-1) x min(-1) for 3 min) or TMP (10 mg x kg(-1) x min(-1) for 3 min) followed by TP. In PVL rats, infusion of vehicle followed by TP induced significant reduction of portal venous pressure (PVP, -15.0+/-1.0%) and prominent elevation of mean arterial pressure (MAP, 57.3+/-8.1%) as well as total peripheral resistance (TPR, 113+/-11%) from baseline, and there was a cardiodepressant response (cardiac index, CI, -26.3+/-1.1%). Infusion of TMP followed by TP induced significant reduction of PVP (-20.3+/-0.4%) and CI (-9.9+/-1.2%) and significant elevation of MAP (31.3+/-2.5%) and TPR (46.0+/-4.1%) from baseline. In BDL rats, infusion of vehicle followed by TP also induced significant reduction of PVP (-13.8+/-1.7%) but an increase in MAP (57.1+/-2.2%) and TPR (101+/-6%) from baseline, and there also was a cardiodepressant response (CI, -21.4+/-2.3%). Infusion of TMP followed by TP induced significant reduction of PVP (-18.9+/-1.4%) and CI (-11.9+/-2.1%), but an increase in MAP (36.2+/-2.5%) and TPR (55.0+/-5.2%). Compared with vehicle followed by TP, TMP not only significantly enhanced portal hypotensive (PVP reduction) effects of TP but also attenuated the systemic pressor (MAP and TPR elevation) and cardiodepressant (CI reduction) effects of TP in both PVL and BDL rats. Our results suggest that TP, alone or in combination with TMP, induced portal hypotensive effects in two models of portal hypertensive rats. Combination of TP and TMP was beneficial in enhancing portal hypotensive effects of TP and ameliorating the systemic pressor and cardiodepressant effects of TP.

Is resuscitation after traumatic suicide attempt a futile effort? A five-year review at a level I trauma center

A retrospective analysis of all traumatic suicide attempts at a Level I regional trauma center between 1990 and 1994 was performed. Data were obtained from the trauma registry, charts, computer data, and telephone interviews. Age, gender, mechanism of injury, and prior mental status were noted. Repeat suicide attempts/ideation, postinjury employment status, and subsequent deaths were recorded. Nontraumatic attempts and successful suicides not transported to the hospital were excluded. Ninety-one patients (71 males and 20 females) with attempted suicide were identified. Average patient age was 33.6 years. Method of attempted suicide and deaths by that method were: firearms (n = 55 attempts/36 deaths), sharp instrumentation (n = 22 attempts/0 deaths), and others. Mortality by firearms and all other mechanisms were 65.0 per cent and 8.3 per cent, respectively. Fifty-two patients survived to be discharged from the hospital. Follow-up data were available for 38 patients with a mean follow-up interval of 53.6 months. Three subsequent deaths were confirmed. The mortality from the index attempt was 42.9 per cent. Mortality by firearms was significantly higher than by all other mechanisms. Patients with chronic mental illness had a significantly higher incidence of subsequent suicide attempts/ideation and unemployment. Confirmed mortality at follow-up was only eight per cent (mean, 53.6 months), and all were patients with chronic mental illness.

The midpoint potentials for the oxidized-semiquinone couple for Gly57 mutants of the Clostridium beijerinckii flavodoxin correlate with changes in the hydrogen-bonding interaction with the proton on N(5) of the reduced flavin mononucleotide cofactor as measured by NMR chemical shift temperature dependencies

In the Clostridium beijerinckii flavodoxin, the reduction of the flavin mononucleotide (FMN) cofactor is accompanied by a local conformation change in which the Gly57-Asp58 peptide bond "flips" from primarily the unusual cis O-down conformation in the oxidized state to the trans O-up conformation such that a new hydrogen bond can be formed between the carbonyl group of Gly57 and the proton on N(5) of the neutral FMN semiquinone radical [Ludwig, M. L., Pattridge, K. A., Metzger, A. L., Dixon, M. M., Eren, M., Feng, Y., and Swenson, R. P. (1997) Biochemistry 36, 1259-1280]. This interaction is thought to contribute to the relative stabilization of the flavin semiquinone and may be at least partially responsible for the substantial separation of the midpoint potentials of the two one-electron reduction steps. Through a series of amino acid substitutions, the above cited study demonstrated the critical role of the often conserved glycine residue in this process. However, it has not been directly established experimentally as to whether these substitutions brought about the changes in the midpoint potentials by altering the strength of this hydrogen-bonding interaction as proposed. In this study, the relative strengths of the FMN N(5)H.O57 hydrogen bond in wild type and the G57A, G57N, and G57T mutants were evaluated by measuring the temperature dependency of the chemical shift for the proton on N(5) of the fully reduced cofactor by 1H-15N HSQC nuclear magnetic resonance spectroscopy. Based on the established correlation between the temperature coefficient of amide protons and the strength of hydrogen bonding in small peptides, the apparent strength of the N(5)H.O57 interaction was found to depend on the properties of the side chain at position 57. The glycine residue found in the wild-type flavodoxin appears to provide the strongest interaction while the beta-branched side chain in the G57T mutant provides the weakest. A good correlation was noted between the temperature coefficients of N(5)H and the one-electron reduction potential for the ox/sq couple as well as the binding free energy of the FMN semiquinone in this group of mutants. These results provide more direct quantitative evidence that support the previous hypothesis that this conformation change and the associated formation of the hydrogen bonding interaction with N(5)H of the reduced FMN represent an important means of stabilizing the neutral semiquinone and in modulating the oxidation-reduction potentials of the flavin cofactor in this and perhaps other flavodoxins.

Acute hemodynamic effects of tetramethylpyrazine and tetrandrine on cirrhotic rats

The hemodynamic effects of tetramethylpyrazine (TMP) and tetrandrine (TET), both alkaloids isolated from Chinese herbs Ligusticum wallichii Franch and Stephania tetrandra S. Moore, respectively, were assessed in anesthetized cirrhotic rats. TMP induced dose-dependent decreases of portal venous pressure (P.V.P.) and mean arterial pressure (M.A.P.) after intravenous infusion. The maximum percentage reduction of P.V.P. after TMP was 3.6 +/- 0.8%, 6.8 +/- 0.5%, and 17.8 +/- 0.6% of baseline, respectively, for the dosages given (3.0, 9.9 and 30.0 mg/kg). Similarly, TET induced dose-dependent decreases of P.V.P. and M.A.P. The maximum percentage reduction of P.V.P. after TET was 5.4 +/- 1.0%, 9.2 +/- 0.8%, and 23.7 +/- 1.2% of baseline, respectively, for the dosages given (2.0, 6.6 and 20.0 mg/kg). Total peripheral resistance was also reduced by TMP as well as TET. Our results showed that TMP and TET induced P.V.P. reduction in cirrhotic rats, together with reduction in M.A.P. and total peripheral resistance.

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of substituted 3-chloro-5,8-dimethoxy-1,4-naphthoquinone and related compounds

2-Amino (6), 2-alkylamino (7-8), 2-methoxy (9), 2-acetamido (10), and 5,8-diacetoxy (11) derivatives of the lead compound 2,3-dichloro-5,8-dimethoxy-1,4-naphthoquinone (4) were synthesized, together with 6,7-dichloro-5,8dimethoxy-1,4-naphthoquinone (5), a positional isomer of 4. Antiplatelet, antiinflammatory, and antiallergic activities were evaluated, and most compounds were quite potent in all assays. Compounds 5 and 9-11 were especially active; however, 5 was ineffective against neutrophil superoxide formation, and 10 was ineffective against mast cell degranulation.