Analysis of portal venous waveform after living-related liver transplantation with pulsed Doppler ultrasound

We evaluate the portal venous waveform (PVW) with pulsed Doppler ultrasound (US) after living-related liver transplantation (LRLT) and correlate it with subsequent abnormalities. In the first 2 wk after LRLT, pulsed Doppler US demonstrated three types of PV waveform (PVW) in 33 recipients: non-phasic PVW in 19 patients, pulsatile in 10, and turbulent in 4. In the pulsatile PVW group, arterio-portal (A-P) shunt was confirmed in three grafts by either arteriograhy or computed tomography during hepatic arteriography. A severe stenosis in the grafted vein was confirmed in one case by both US and venography. The pulsatile PVW in the remaining six cases spontaneously disappeared and turned to the non-phasic PVW without treatment. The graft volume/liver standard volume (GV/SV) ratio was significantly smaller in the pulsatile PV waveform group than in the non-phasic PVW group (p<0.01). In the turbulent PVW group, aneurysmal-like dilatation of the portal vein at the umbilical portion was formed in 3 of the 4 patients. The pulsatile waveform in the PV is frequently observed with pulsed Doppler after LRLT, especially in patients that received small grafts. We should keep in mind that they often disappear without any treatment, although some examples of pulsatile waveforms represent vascular complications.

[Intentional neck-plastic incomplete clipping followed by coil embolization for broad-necked distal BA aneurysms]

OBJECTIVE

We report three patients with broad-necked distal basilar artery (BA) aneurysms treated with intentional incomplete clipping followed by endovascular occlusion using Guglielmi detachable coils.

METHODS

The location of the aneurysms was BA bifurcation in one patient and BA-superior cerebellar artery (SCA) in two. One patient presented with acute subarachnoid hemorrhage and two patients had incidental aneurysms. In two patients, endovascular treatment was thought to be difficult considering the morphology of the aneurysms and surgical treatment was performed as the first choice of treatment. One patient with a BA-SCA aneurysm underwent endovascular treatment using a remodelling technique first. However, it was impossible to place the coil preserving SCA, so surgical treatment was performed. In all patients, the attempt to pursue complete clipping was considered to be accompanied with high risks of morbidity, so neck-plastic incomplete clipping was performed intentionally. One to six days after the surgery, coil embolization was performed.

RESULTS

In all patients, complete occlusion of the aneurysms was achieved and all patients had excellent clinical outcomes.

CONCLUSION

Intentional neck-plastic incomplete clipping followed by endovascular coiling may be a useful treatment option for patients with broad-necked distal BA aneurysms.

Inhibitory effect of somatostatin on cholecystokinin release is independent of luminal cholecystokinin-releasing factor content in conscious rats

INTRODUCTION

Exclusion of bile-pancreatic juice from the intestine increases pancreatic secretion via cholecystokinin (CCK) release in conscious rats. Luminal CCK-releasing factor (LCRF), purified from rat intestinal secretions, is an intraluminal regulator of CCK secretion during bile-pancreatic juice diversion.

AIMS

Because somatostatin is a potent inhibitor of CCK release and pancreatic secretion, the inhibitory effect of somatostatin on LCRF was examined.

METHODOLOGY

Rats were prepared with bile and pancreatic cannulae and two duodenal cannulae and with an external jugular vein cannula. The experiments were conducted without anesthesia. After 1.5-hour basal collection of pancreatic juice with bile-pancreatic juice return, bile-pancreatic juice was diverted for 2 hours, during which time somatostatin (2, 10 nmol/kg/h) was infused intravenously. The rats were killed before and 1 and 2 hours after bile-pancreatic juice diversion. To examine the effect of luminal somatostatin, 50 or 200 nmol/kg/h of somatostatin was infused into the duodenum. The plasma CCK and luminal content of LCRF were measured by specific radioimmunoassays.

RESULTS

Bile-pancreatic juice diversion significantly increased pancreatic secretion, plasma CCK, and LCRF levels. Intravenous infusion of somatostatin inhibited CCK release and pancreatic secretion, but not LCRF content. Luminal administration of somatostatin did not show any effect.

CONCLUSION

Inhibitory effect of circulating somatostatin on CCK release and pancreatic secretion is independent of LCRF content.

Effect of Phenyl-P/HEMA acetone primer on wet bonding to EDTA-conditioned dentin

OBJECTIVES

The purpose of this study was to examine the effect of 2-methacryloyloxyethyl phenyl phosphoric acid (Phenyl-P)/2-hydroxyethyl methacrylate (HEMA) acetone-based primer on moist dentin surfaces that were preconditioned with ethylenediaminetetraacetate (EDTA) to remove the smear layer.

METHODS

Bovine dentin were prepared with 180-grit paper, conditioned with 0.5M EDTA (pH 7.4) for 60s followed by water rinsing and then blot drying. Each surface was then primed with Phenyl-P/30 wt% HEMA in acetone for 10s followed by blot drying. A light-cured bonding agent was then applied, cured and trimmed to give dumbbell-shaped specimens. The Phenyl-P concentration ranged from 1 to 20 wt%. During the bonding procedure, no compressed air was used. After storage in water at 37 degrees C for one day, tensile bond strengths were measured and analyzed using one-way ANOVA. Dentin discs treated under the same conditions were observed under a scanning electron microscope (SEM).

RESULTS

When the concentration of Phenyl-P was 12 wt%, the highest mean tensile bond strength was obtained (27 MPa). It was significantly higher than that of the 3, 5, 15 or 20 wt% groups (9-11 MPa) (p<0.05). The samples of 1 wt% group were all broken during trimming the dumbbell-shaped specimens. SEM observations showed a 1 microm-thick layer of hybridized dentin after polished cross-sections were chemically challenged with 6N HCl for 30s and then 1% NaOCl for 60 min.

SIGNIFICANCE

The experimental Phenyl-P/HEMA acetone primer is effective in bonding resin to EDTA-conditioned dentin. Acetone as a solvent for Phenyl-P/HEMA primer has the clinical advantage of not requiring an air-stream to evaporate the solvent. The experimental bonding procedure can minimize the skin irritation by HEMA.

Initial experience of percutaneous renal cryosurgery under the guidance of a horizontal open MRI system

OBJECTIVE

The aim of this study was to obtain preliminary results of cryoablation of renal tumors by using a percutaneous approach guided by a horizontal open MRI system, and to assess the safety and efficacy of this procedure.

MATERIALS AND METHODS

Four patients with renal tumors underwent percutaneous cryosurgery with local anesthesia using a horizontal open MRI system (AIRIS II, Hitachi Medical Corp., Tokyo, Japan). The size of the mass was radiographically documented as 4 cm or less in diameter. A 2- or 3-mm cryoprobe was advanced into the renal mass under real-time MR monitoring. Growth of the iceball during cryoablation was monitored by two-dimensional MR images. Follow-up dynamic CT and physical examination were done after two weeks and six weeks.

RESULT

MR imaging demonstrated the iceballs as sharply marginated regions of signal loss that expanded and engulfed the renal mass with clear contrast between the iceball and surrounding tissue. Cryoablated tumors resolved, and there were no serious complications and no clinically significant changes during the procedures and follow-up study.

CONCLUSION

In this limited clinical trial of percutaneous renal tumor surgery, cryoablation demonstrated its feasibility with minimal morbidity. Intraprocedual MR-guided cryosurgery can be used as a safe modality, although further studies are necessary to determine the long-term efficacy of this procedure.

Importance of CCK-A receptor for gallbladder contraction and pancreatic secretion: a study in CCK-A receptor knockout mice

Bile and pancreatic secretions were determined in a CCK-A receptor deficient mouse mutant generated by gene targeting in embryonic stem cells. The targeting vector contained lacZ and neo insertions in exon 2. Under the urethane anesthesia, the common bile duct was cannulated, and the mixture of bile-pancreatic juice was collected every 30 min. After the 1 h basal secretion, CCK-8 (0.5 and 1.0 nmol/kg), acetylcholine (500 nmol/kg), and neuromedin C (1.0 micromol/kg) were injected subcutaneously, and the secretions were collected following 1 h. Amylase and bile acid outputs were determined as parameters of pancreatic secretion and gallbladder contraction, respectively. In some CCK-A receptor (+/-) animals, LacZ staining was performed. CCK-8 significantly increased amylase and bile acid outputs in CCK-A receptor (+/+) and (+/-) mice, whereas no response was observed in (-/-) mice. Neuromedin C and acetylcholine increased amylase secretion in CCK-A receptor (-/-) mice similar to (+/-) and (+/+) mice. The same doses of neuromedin C and acetylcholine could not increase bile acid secretion. The gallbladder smooth muscles, pancreatic acinar cells, duct cells, and islets were stained by LacZ. CCK and CCK-A receptor are important for pancreatic secretion and gallbladder contraction. Neuromedin C and acetylcholine may compensate pancreatic function, but not gallbladder contraction.

Comparison of lung protection strategies using conventional and high-frequency oscillatory ventilation

This study compared pathophysiological and biochemical indexes of acute lung injury in a saline-lavaged rabbit model with different ventilatory strategies: a control group consisting of moderate tidal volume (V(T)) (10-12 ml/kg) and low positive end-expiratory pressure (PEEP) (4-5 cmH(2)O); and three protective groups: 1) low V(T) (5-6 ml/kg) high PEEP, 2-3 cmH(2)O greater than the lower inflection point; 2) low V(T) (5-6 ml/kg), high PEEP (8-10 cmH(2)O); and 3) high-frequency oscillatory ventilation (HFOV). The strategy using PEEP > inflection point resulted in hypotension and barotrauma. HFOV attenuated the decrease in pulmonary compliance, the lung inflammation assessed by polymorphonuclear leukocyte infiltration and tumor necrosis factor-alpha concentration in the alveolar space, and pathological changes of the small airways and alveoli. Conventional mechanical ventilation using lung protection strategies (low V(T) high PEEP) only attenuated the decrease in oxygenation and pulmonary compliance. Therefore, HFOV may be a preferable option as a lung protection strategy.

Detection of lung tumor movement in real-time tumor-tracking radiotherapy

PURPOSE

External radiotherapy for lung tumors requires reducing the uncertainty due to setup error and organ motion. We investigated the three-dimensional movement of lung tumors through an inserted internal marker using a real-time tumor-tracking system and evaluated the efficacy of this system at reducing the internal margin.

METHODS AND MATERIALS

Four patients with lung cancer were analyzed. A 2.0-mm gold marker was inserted into the tumor. The real-time tumor-tracking system calculates and stores three-dimensional coordinates of the marker 30 times/s. The system can trigger the linear accelerator to irradiate the tumor only when the marker is located within the predetermined "permitted dislocation." The value was set at +/-1 to +/-3 mm according to the patient's characteristics. We analyzed 10,413-14,893 data sets for each of the 4 patients. The range of marker movement during normal breathing (beam-off period) was compared with that during gated irradiation (beam-on period) by Student's t test.

RESULTS

The range of marker movement during the beam-off period was 5.5-10.0 mm in the lateral direction (x), 6.8-15.9 mm in the craniocaudal direction (y) and 8.1-14.6 mm in the ventrodorsal direction (z). The range during the beam-on period was reduced to within 5.3 mm in all directions in all 4 patients. A significant difference was found between the mean of the range during the beam-off period and the mean of the range during the beam-on period in the x (p = 0.007), y (p = 0.025), and z (p = 0.002) coordinates, respectively.

CONCLUSION

The real-time tumor-tracking radiotherapy system was useful to analyze the movement of an internal marker. Treatment with megavoltage X-rays was properly given when the tumor marker moved into the "permitted dislocation" zone from the planned position.

Diffusion-weighted MR findings in a reversible case of acute Wernicke encephalopathy

We report a case of acute Wernicke encephalopathy (WE) in which apparent diffusion coefficient maps showed areas of increased diffusion in the bilateral medial thalami that corresponded to the hyperintense lesions on T2-weighted imaging. The hyperintense lesions on T2-weighted imaging disappeared with full recovery from symptoms. These findings suggest that the hyperintense lesions of the acute changes of WE include reversible vasogenic edema and are not caused by acute ischemia.

Clinical efficacy of telemedicine in emergency radiotherapy for malignant spinal cord compression

The authors developed a Telecommunication-HElped Radiotherapy Planning and Information SysTem (THERAPIST), then estimated its clinical benefit in radiotherapy in district hospitals where consultation with the university hospital was required. The system consists of a personal computer with an image scanner and a digital camera, set up in district hospitals and directly connected via ISDN to an image server, and a treatment planning device set up in a university hospital. Image data and consultative reports are sent to the server. Radiation oncologists at the university hospital determine a treatment schedule and verify actual treatment fields. From 1998 to 1999, 12 patients with malignant spinal cord compression (MSCC) were treated by emergency radiotherapy with the help of this system. Image quality, transmission time, and cost benefit also were satisfactory for clinical use. The mean time between the onset of symptoms and the start of radiotherapy was reduced significantly from 7.1 days to 0.8 days (P < .05) by the introduction of the system. Five of 6 nonambulant patients became ambulant after the introduction of THERAPIST compared with 2 of 8 before the introduction of THERAPIST. The treatment outcome was significantly better after the introduction of the system (P < .05), and suggested to be beyond the international standard. The telecommunication-helped radiotherapy and information system was useful in emergency radiotherapy in district hospitals for patients with MSCC for whom consultation with experienced radiation oncologists at a university hospital was required.

Overexpression of homeobox gene HOXD3 induces coordinate expression of metastasis-related genes in human lung cancer cells

Homeobox-containing genes are expressed in spatiotemporal fashion during embryogenesis and act as master transcription-regulating factors which control the expression of a variety of genes involved in morphogenesis. They are also expressed in a tissue-specific manner in normal adult tissues and appear to give cells spatial information in the maintenance of their architectural integrity. We transfected a HOXD3 class I homeobox-containing gene into human lung cancer A549 cells and investigated alterations in gene expressions and phenotypes related to the maintenance of tissue architecture in HOXD3-overexpressing A549 cells. In the HOXD3-overexpressing cell lines, expression of E-cadherin was lost and plakoglobin was strongly repressed, whereas integrin alpha3 and beta3 were up-regulated and N-cadherin and integrin alpha4 were newly expressed. Compared with parental and control transfectant lines, the HOXD3-overexpressing cell lines showed highly motile and invasive activity. Blocking experiments using anti-integrin beta1 and beta3 suggested that the increased haptotaxis of the HOXD3-overexpressing cells to vitronectin resulted from increased expression and activation of integrin alphavbeta3, and that overexpression of the HOXD3 gene converted the integrin beta1-dependent haptotaxis to fibronectin into both integrin beta1- and beta3-dependent one. HOXD3 overexpression increased production of matrix-degrative enzymes including matrix metalloproteinase-2 and urokinase-plasminogen activator. When the tumor cells were intravenously injected into the tail veins of nude mice, HOXD3 transfectants formed a significantly large number of metastatic foci in lungs compared with the control transfectants. These findings suggest that HOXD3 can act as a metastasis-promoting gene in human lung cancer A549 cells.

MR imaging of the brain in lymphomatoid granulomatosis

BACKGROUND AND PURPOSE

Clinical diagnosis of lymphomatoid granulomatosis (LG) of the brain, in patients without skin or chest lesions, usually is difficult because of the nonspecific neurologic manifestations, laboratory data, and CT appearance. Our aim was to characterize the MR appearance of LG of the brain.

METHODS

We retrospectively reviewed the MR images in four patients (35 to 72 years old) with histologically confirmed LG of the brain.

RESULTS

On T2-weighted images, we noted diffuse hyperintense lesions in the cerebral white matter bilaterally (n = 3), in the brain stem and cerebellar hemisphere (n = 1), and patchy hyperintense lesions the brain stem (n = 2). On contrast-enhanced T1-weighted images, we observed multiple punctate or linear enhancements residing along the perivascular space (n = 4), nodular enhancements (n = 2), ringlike enhancements (n = 1), and a large, enhanced mass (n = 1). All patients had multifocal lesions.

CONCLUSION

Although the MR appearance of LG of the brain varies, multiple punctate or linear enhancements that reside along the perivascular space suggest LG.

MRI in seven cases of tacrolimus (FK-506) encephalopathy: utility of FLAIR and diffusion-weighted imaging

We assessed the utility of fluid-attenuated inversion-recovery (FLAIR) and diffusion-weighted (DWI) images in investigation of tacrolimus (FK-506) encephalopathy, and to see whether we could predict its cause from clinical and imaging data. In seven patients with presumed FK-506 toxicity the areas involved on MRI were similar to those in cyclosporin A (CsA) toxicity. The abnormal signal was most evident on FLAIR in all cases. In three of four patients who underwent DWI, no diffusion abnormalities were detected; in the remaining patient, increased diffusion was seen in the deep white matter bilaterally on the apparent diffusion coefficient map, consistent with the findings on T2-weighted spin-echo and FLAIR images. Five of the six patients for whom we had clinical data showed sudden changes in electrolyte or fluid equilibrium due to diarrhoea, a polyuria or oliguria one day before or on the day of onset of the central nervous system disturbances. We speculate that FK-506 encephalopathy is triggered by the disturbance of the electrolyte and/or fluid equilibrium, given a certain serum level of FK-506.

HTLV-1-associated bronchopneumonopathy (HAB): CT-pathological correlation

We describe the thin-section CT appearances of HTLV-1-associated bronchopneumonopathy, with histopathological correlation, in two biopsy proven cases.

Cholecystokinin-8 (CCK-8) has no effect on heart rate in rats lacking CCK-A receptors

Heart rate responses to i.v. administration of cholecystokinin-8 (CCK-8) were investigated in Otsuka Long-Evans Tokushima Fatty (OLETF) rats lacking CCK-A receptors and control Long-Evans Tokushima Otsuka (LETO) rats. The heart rate decreased after i.v. administration of 3 nmol.kg(-)(1) of CCK-8 in LETO rats, but not in OLETF rats. Bradycardia in the LETO rats disappeared after treatment with MK-329, but not after treatment with L-365,260. The expression of CCK-A receptor precursor mRNA was found exclusively in the atrium in LETO rats. These results suggest that CCK-8 decreases heart rate via CCK-A receptors located in the atrium of the rats.

Magnetic resonance imaging system for three-dimensional conformal radiotherapy and its impact on gross tumor volume delineation of central nervous system tumors

PURPOSE

We developed an MRI system for three-dimensional planning in radiotherapy. Its contribution on gross tumor volume (GTV) delineation of central nervous system (CNS) diseases was evaluated.

METHODS AND MATERIALS

The MRI system, with corrected distortion, was registered on computed tomography (CT) by means of fiducial/anatomic landmarks. In 41 consecutive patients with various CNS diseases, GTVs determined by MRI/CT registration (MR/CT-GTV) and CT alone (CT-GTV) were compared. Hard copies of diagnostic MRI were shown to doctors when CT-GTV was determined to simulate a conventional planning situation. Multi-observer volumetric analysis was conducted, assessing interobserver deviations among four radiation oncologists and intermethodological deviations between MR/CT-GTV and CT-GTV.

RESULTS

Overall, the mean of geometric distortion was significantly reduced from 1.08 mm to 0.3 mm by distortion correction (p < 0.0001). The contribution of the correction was apparent at >12.0 cm radius from the center of the magnetic field. Interobserver deviation was significantly reduced by MR/CT registration (p = 0.005). The improvement was significant for acoustic neurinoma (p = 0.038), astrocytomas (p = 0.043), and lesions at the cerebellum/brainstem (p = 0.008). The regression coefficient between MR/CT-GTV and CT-GTV was <0.9 for cerebellum/brainstem lesions, suggesting that MRI/CT-GTV was smaller than CT-GTV.

CONCLUSIONS

This system is feasible for three-dimensional planning and was shown to reduce interobserver deviations in GTV delineation for CNS diseases.

Intramedullary schwannoma of the spinal cord: report of two cases

We report magnetic resonance findings in the intramedullary schwannoma of the cervical spinal cord in two patients. In both cases, the solid portions of the tumours enhanced intensely after administration of Gd-DTPA and the enhanced border was sharply delineated from the adjacent spinal cord. Schwannomas should be considered in the differential diagnosis of intramedullary tumours when magnetic resonance images show a strongly enhancing mass with sharply delineated borders.

[Radiological assessment of the structural relationship between the trachea and the innominate artery in physically disabled and scoliotic children]

Studies were made on the physically disabled and scoliotic children who underwent tracheostomy. The purpose was to clarify factors that might lead to the tracheo-innominate artery fistula, by use of three-dimensional helical CT (3 DCT). In a case of right scoliosis, the tracheo-innominate artery fistula may be caused by the left-ward displacement of the trachea from the vertebra, having the innominate artery ride over the trachea and compressing it. In a case of the physically disabled and scoliotic children, there may be more compression on the trachea by the innominate artery along with the worsening scoliosis. Therefore, we consider it necessary to examine the structural relationship between the trachea, the vertebra, and the innominate artery periodically by 3 DCT.

Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma

PURPOSE

The rate of hearing loss in a population before and after irradiation was investigated to determine the effect of irradiation on hearing impairment.

METHODS AND MATERIALS

In 72 patients with vestibular schwannoma who received fractionated stereotactic irradiation from 1992 to 1999, 21 had had their hearing levels examined 3 months or more before the treatment. The mean time between the initial examination and treatment was 18.6 months (range: 3-89 months), and the mean time between treatment and the last follow-up was 24.2 months (12-69 months). Thirty-six to 50 Gy in 20-25 fractions over 5 to 6 weeks was given using an X-ray beam from a linear accelerator. Pure tone average (PTA) was measured using the mean hearing level at five frequencies, and the annual rate of hearing loss was defined as [(hearing loss in PTA(dB))/(follow-up period (months)x12)].

RESULTS

The actual cumulative curve of decrease in tumor size of 2 mm or more was 38.3% at 2 years and 80.0% at 3 years. The mean of hearing loss in PTA was 11.6+/-10.3 dB (-1 to 35 dB) from the initial examination to the start of irradiation and 11.9+/-14.4 dB (-14 to 37 dB) from the start of irradiation to the last follow-up. The mean annual rates of hearing loss before irradiation and in the 1st,2nd,3rd and 4th years after irradiation were, respectively, 18.6, 11.2, 6.2, 5.1, and 5.0 dB/year. The annual rates of hearing loss in the 2nd year (P=0.025) and 3rd year (P=0.018) were significantly slower than the rate before irradiation.

CONCLUSIONS

The mean annual rate of hearing loss was higher before irradiation than after irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, fractionated stereotactic irradiation was suggested to be effective to lower the rate of hearing loss.