Ancilla-assisted quantum process tomography

Complete and precise characterization of a quantum dynamical process can be achieved via the method of quantum process tomography. Using a source of correlated photons, we have implemented several methods, each investigating a wide range of processes, e.g., unitary, decohering, and polarizing. One of these methods, ancilla-assisted process tomography (AAPT), makes use of an additional "ancilla system," and we have theoretically determined the conditions when AAPT is possible. Surprisingly, entanglement is not required. We present data obtained using both separable and entangled input states. The use of entanglement yields superior results, however.

Thalamic activation during an attention-to-prepulse startle modification paradigm: a functional MRI study

BACKGROUND

Prepulse inhibition (PPI) of the startle reflex reflects early stages of information processing and is modulated by selective attention. Animal models indicate medial frontal-thalamic circuitry is important in PPI modulation. We report data from the first functional magnetic resonance imaging (fMRI) study examining whether attending to or ignoring a prepulse differentially activates brain areas within this circuitry.

METHODS

Ten healthy subjects received structural and functional MRI. During fMRI acquisition, subjects heard intermixed attended and ignored tones serving as prepulses to the startle stimulus. Regions of interest were traced on structural MRI and coregistered to fMRI images.

RESULTS

Greater amplitude fMRI blood-oxygen-level-dependent response to attended than ignored PPI conditions occurred in the right thalamus, and bilaterally in the anterior and mediodorsal thalamic nuclei, whereas the startle-alone condition showed deactivation. In transitional medial cortex (Brodmann Area 32), which is involved in affective processing of noxious stimuli, the startle-alone condition elicited the greatest response, the attended-PPI condition showed the smallest response, and the ignored-PPI condition was intermediate.

CONCLUSIONS

These findings extend animal models to humans by indicating thalamic involvement in the modulation of PPI. Further fMRI investigations may elucidate other key structures in the circuitry underlying normal and disordered modulation of PPI.

Differential amygdala activation during emotional decision and recognition memory tasks using unpleasant words: an fMRI study

This study used fMRI to examine the response of the amygdala in the evaluation and short-term recognition memory of unpleasant vs. neutral words in nine right-handed healthy adult women. To establish specificity of the amygdala response, we examined the fMRI BOLD signal in one control region (visual cortex). Alternating blocks of unpleasant and neutral trials were presented. During the emotional decision task, subjects viewed sets of three unpleasant or three neutral words while selecting the most unpleasant or neutral word, respectively. During the memory task, subjects identified words that were presented during the emotional decision task (0.50 probability). Images were detrended, filtered, and coregistered to standard brain coordinates. The Talairach coordinates for the center of the amygdala were chosen before analysis. The BOLD signal at this location in the right hemisphere revealed a greater amplitude signal for the unpleasant relative to the neutral words during the emotional decision but not the memory task, confirmed by Time Course x Word Condition ANOVAs. These results are consistent with the memory modulatory view of amygdala function, which suggests that the amygdala facilitates long-term, but not short-term, memory consolidation of emotionally significant material. The control area showed only an effect for Time Course for both the emotional decision and memory tasks, indicating the specificity of the amygdala response to the evaluation of unpleasant words. Moreover, the right-sided amygdala activation during the unpleasant word condition was strongly correlated with the BOLD response in the occipital cortex. These findings corroborate those by other researchers that the amygdala can modulate early processing of visual information in the occipital cortex. Finally, an increase in subject's state anxiety (evaluated by questionnaire) while in the scanner correlated with amygdala activation under some conditions.

Effect of fluoxetine on regional cerebral metabolism in autistic spectrum disorders: a pilot study

The regional metabolic effects of fluoxetine were examined in patients with autism spectrum disorders. Six adult patients with DSM-IV and Autism Diagnostic Interview (ADI) diagnoses of autism (n = 5) and Asperger's syndrome (n = 1), entered a 16-wk placebo-controlled cross-over trial of fluoxetine. The patients received (18)F-deoxyglucose positron emission tomography with co-registered magnetic resonance imaging at baseline and at the end of the period of fluoxetine administration. After treatment, the patients showed significant improvement on the scores of the Yale--Brown Obsessive--Compulsive Scale -- Obsessions subscale and the Hamilton Anxiety Scale; Clinical Global Impressions -- Autism scores showed 3 of the patients much improved and 3 unchanged. Relative metabolic rates were significantly higher in the right frontal lobe following fluoxetine, especially in the anterior cingulate gyrus and the orbitofrontal cortex. Patients with higher metabolic rates in the medial frontal region and anterior cingulate when unmedicated were more likely to respond favourably to fluoxetine. These results are consistent with those in depression indicating that higher cingulate gyrus metabolic rates at baseline predict SRI response.

Patterns of cortical activity and memory performance in Alzheimer's disease

BACKGROUND

Declarative memory changes are the hallmark of Alzheimer's disease, although their functional neuroanatomy is not restricted to a single structure. Factor analysis provides statistical methods for evaluating patterns of cerebral changes in regional glucose uptake.

METHODS

Thirty-three Alzheimer's patients and 33 age- and gender-matched control subjects were studied with magnetic resonance imaging and positron emission tomography with [(18)F] deoxyglucose. During the tracer-uptake period, subjects performed a serial verbal learning task. Cortical activity was measured in 32 regions of interest, four in each lobe on both hemispheres.

RESULTS

Factor analysis with varimax rotation identified seven factors explaining 80% of the variance ("parietal cortex," "occipital cortex," "right temporo-prefrontal areas," "frontal cortex," "motor strip," "left temporal cortex," and "posterior temporal cortex"). Relative to control subjects, Alzheimer's patients showed significantly reduced values on the factors occipital cortex, right temporo-prefrontal areas, frontal cortex, and left temporal cortex. The factor temporo-prefrontal areas showed large differences between patients with good and poor performance, but little difference when control subjects were similarly divided.

CONCLUSIONS

Findings suggest that Alzheimer's disease is characterized by altered patterns of cortical activity, rather than deficits in a single location, and emphasize the importance of right temporo-prefrontal circuitry for understanding memory deficits.

Regional and global changes in cerebral diffusion with normal aging

BACKGROUND AND PURPOSE

We used quantitative diffusion MR imaging to investigate the microstructural changes that occur in white matter during normal aging in order to identify regional changes in anisotropy and to quantify global microstructural changes by use of whole-brain diffusion histograms.

METHODS

Full diffusion tensor MR imaging was performed in 20 healthy volunteers, 20 to 91 years old. Thirteen subjects also underwent high-resolution T1-weighted imaging, so that diffusion images could be coregistered and standardized to normal coordinates for statistical probability mapping. Relative anisotropy (RA) was calculated, as was linear regression of RA with age for each pixel; pixels with a significant correlation coefficient were displayed. For histographic analysis, the average apparent diffusion coefficient (ADC) histograms were calculated on a pixel-by-pixel basis. Subjects were divided into two equal groups by the median age (55 years) of the population and plotted for statistical comparison.

RESULTS

Regional analysis showed statistically significant decreases in RA with increasing age in the periventricular white matter, frontal white matter, and genu and splenium of the corpus callosum, despite the absence of signal abnormalities on visual inspection of conventional images. Significant increases in RA were found in the internal capsules bilaterally. ADC histograms showed higher mean ADC and reduced peak height and skew in the older age group on group comparisons.

CONCLUSION

Quantitative diffusion histograms correlate with normal aging and may provide a global assessment of normal age-related changes and serve as a standard for comparison with neurodegenerative diseases.

Limbic circuitry in patients with autism spectrum disorders studied with positron emission tomography and magnetic resonance imaging

OBJECTIVE

Cytoarchitectonic changes in the anterior cingulate cortex, hippocampus, subiculum, entorhinal cortex, amygdala, mammillary bodies, and septum were reported in a postmortem study of autism. Previously, the authors found smaller cingulate volume and decreased metabolism of the cingulate in seven autistic patients. In this study, they measured the volume and glucose metabolism of the amygdala, hippocampus, and cingulate gyrus in an expanded group of 17 patients with autism spectrum disorders (autism [N=10] or Asperger's disorder [N=7]) and 17 age- and sex-matched healthy volunteers.

METHOD

Subjects performed a serial verbal learning test during (18)F-deoxyglucose uptake. The amygdala, hippocampus, and cingulate gyrus were outlined on magnetic resonance imaging scans, volumes of the structures were applied to matching coregistered positron emission tomography scans, and three-dimensional significance probability mapping was performed.

RESULTS

Significant metabolic reductions in both the anterior and posterior cingulate gyri were visualized in the patients with autism spectrum disorders. Both Asperger's and autism patients had relative glucose hypometabolism in the anterior and posterior cingulate as confirmed by analysis of variance; regional differences were also found with three-dimensional significance probability mapping. No group differences were found in either the metabolism or the volume of the amygdala or the hippocampus. However, patients with autism spectrum disorders showed reduced volume of the right anterior cingulate gyrus, specifically in Brodmann's area 24'.

CONCLUSIONS

Compared with age- and sex-matched healthy volunteers, patients with autism spectrum disorders showed significantly decreased metabolism in both the anterior and posterior cingulate gyri.

Three-dimensional analysis with MRI and PET of the size, shape, and function of the thalamus in the schizophrenia spectrum

OBJECTIVE

In an exploration of the schizophrenia spectrum, the authors compared thalamic size, shape, and metabolic activity in unmedicated patients with schizophrenia and schizotypal personality disorder to findings in age- and sex-matched healthy control subjects.

METHOD

Coregistered magnetic resonance imaging (MRI) and positron emission tomography scans were obtained in 27 schizophrenic patients, 13 patients with schizotypal personality disorder, and 32 control subjects who performed a serial verbal learning test during tracer uptake. After thalamus edges were outlined on 1.2-mm MRI scans, a radial warping program yielded significance probability mapping in three dimensions.

RESULTS

Significance probability mapping (with resampling) identified an area in the region of the mediodorsal nucleus bilaterally with significantly lower relative metabolism in the schizophrenia group than in either the control or schizotypal personality disorder groups, which did not differ from each other. The three groups did not differ significantly in total thalamic volume in square millimeters or thalamic volume relative to brain volume. Shape analyses revealed that schizophrenic patients had significantly fewer pixels in the left anterior region, whereas patients with schizotypal personality disorder had significantly fewer pixels in the region of the right mediodorsal nucleus than did control subjects.

CONCLUSIONS

Schizophrenic patients showed significant metabolism and shape differences from control subjects in selective subregions of the thalamus, whereas patients with schizotypal personality disorder showed only a difference in shape. Because the mediodorsal and anterior nuclei have different connections with limbic and prefrontal structures, the anterior thalamic shrinkage and mediodorsal metabolic and shape changes might relate to the different clinical pictures in schizotypal personality disorder and schizophrenia.

Visualizing fronto-striatal circuitry and neuroleptic effects in schizophrenia

Disturbances in fronto-striatal circuitry have been postulated to be important in schizophrenia. Positron emission tomography typically shows decreased metabolic rates in these areas relative to other brain areas in schizophrenia. After treatment with typical neuroleptics, striatal metabolic rates are increased, but other brain areas tend not to show significant changes. Atypical neuroleptics less markedly affect striatal metabolic rates, but show wider cortical effects. In order to examine fronto-striatal circuitry, a technique for visualizing the correlations between metabolic rates in all brain areas was applied in 33 controls and 27 unmedicated schizophrenic patients. Correlation images revealed strong fronto-striatal connections in controls, but weak fronto-striatal links in schizophrenic patients. Changes in striatal circuits, also reflected in recent anatomical studies, may be important for understanding antipsychotic effects.

A method of basal forebrain anatomical standardization for functional image analysis

Functional as well as structural assessment of the basal forebrain has mostly focused on the dorsal caudate and putamen in axial slices where they are easily outlined or their centers located with stereotaxic methods. The more ventral extent of the basal forebrain, where the irregular form and indistinct boundaries of the nucleus accumbens and substantia innominata are difficult to trace and where the brain's ventral surface may contribute partial volume artifacts to measurement, has been less studied. We present a method based on coronal sections, landmarks placed on clearly visible anchor points, and the computational technique of thin-plate spline warping which allows the alignment of groups of individuals to common coordinates for pixel-by-pixel statistical mapping. The reliability of the landmarks across independent raters yields a median absolute difference of 1.3-1.6 mm. The validity of the method is confirmed by variance maps which reveal significant decreases in variance over spindle and bounding box alignment.

Age-related shift in brain region activity during successful memory performance

Coregistered positron emission tomography (PET)/magnetic resonance imaging (MRI) was used to characterize brain function in 70 volunteers, aged 20-87 years, during a verbal memory task. Frontal activity showed an age-related decline that remained significant after statistical control for sulcal atrophy. Analyses of young and old subgroups matched for memory scores revealed that young good performers activated frontal regions, whereas old good performers relied on occipital regions. Although activating different cortical regions, good performers of all ages used the same cognitive strategy semantic clustering. Age-related functional change may reflect dynamic re-allocation in a network of brain areas, not merely anatomically fixed neuronal loss or diminished capacity to perform.

Detection of hepatic neoplasms by computed tomographic arterial portography in cirrhotic patients

Computed tomography (CT) during arterial portography (CTAP) is useful in detecting hepatic tumors but cirrhotic change may interfere with portal flow and the prediction of resectability. We evaluated the usefulness of CTAP in detecting hepatic tumors, especially hepatocellular carcinoma (HCC), in patients with or without cirrhotic change. Ninety-six patients with pathologically proven hepatic tumors were assessed, of whom 90 had hepatocellular carcinoma. The tumors had been previously detected by abdominal ultrasound and CT scans, after which the patients were referred for angiography and CTAP. The CTAP findings were compared with ultrasonographic, conventional CT, angiographic, and subsequent surgical and pathologic findings regarding size, number, and location of the hepatic lesions. CTAP detected 134 of 143 pathologically proven lesions. The overall sensitivity of CTAP in the 96 patients was 94%, with a false-positive rate of 22%. The detection rate of CTAP for tumors less than 2 cm in diameter was high (92%). The sensitivity and false-positive rate for CTAP in 60 cirrhotic patients were 94% and 23%, respectively, CTAP is a sensitive imaging modality for detection of hepatic neoplasms even in patients with cirrhosis, but its false-positive rate is high.

Prevalence of human papilloma virus 16 or 18 in cervical cancer in Hualien, eastern Taiwan

In order to determine the association of human papilloma virus (HPV) with cervical cancer of patients in the Hualien area, we analyzed 40 cervical cancer specimens using polymerase chain reaction (PCR) to detect the presence of HPV type 16 (HPV-16) and type 18 (HPV-18) genomes. The results showed that at least 70% (28/40) of the specimens had HPV DNA. Of the 37 squamous cell carcinomas of the cervix, HPV-16 was present in 25 cases (68%) and HPV-18 in 2 (5.4%). HPV-16 DNA was detected in one of 2 adenocarcinomas and HPV-18 in a case of small cell carcinoma. Seven (87.5%) of 8 specimens from aborigines were HPV-positive. These findings support a role for HPV in the development of cervical cancer in the Hualien population.

Comparison of intravenous granisetron with metoclopramide plus dexamethasone in the prevention of nausea and vomiting associated with emetogenic cytotoxic chemotherapy

Fifty-one patients who received their first course of chemotherapy were studied to compare the respective efficacy and safety of granisetron and metoclopramide plus dexamethasone in the prevention of nausea and vomiting induced by emetogenic cytotoxic drugs. The results showed the response rate of antiemesis in the first 24 hours was higher in the metoclopramide plus dexamethasone group than in the granisetron group: 95% vs 84%. For the next six days of the study period, the response rate of the granisetron group was shown to be more effective than that of metoclopramide plus dexamethasone group: 77% vs 60%. Furthermore, the granisetron seemed to display enhanced tolerability with less drug-related side effects and no extrapyramidal effects which appeared in 2 cases of the metoclopramide plus dexamethasone group. In conclusion, a single dose of granisetron can be as effective as the gold standard of metoclopramide plus dexamethasone regimen in preventing and treating acute nausea and vomiting. For preventing delayed nausea and vomiting, granisetron is shown to be more effective than metoclopramide plus dexamethasone.

Surgical treatment of peptic ulcer disease: changing patterns in the past 40 years

During the past 40 years (1951-1990), 7,663 patients with peptic ulcer disease underwent surgical treatment at the National Taiwan University Hospital. A great change in patient characteristics and operative procedures was noted between the last 10 years and the previous three decades. There were 7,105 patients (92.7%) between 1951 and 1980, an average of 237 patients per year. However, only 558 patients received surgery in the last 10 years, an average of 56 patients per year. The proportion of female patients increased from 9.5% in the earlier period to 20.4% in the last 10 years; the average age of patients also increased. In the earlier period, the indications for surgery were hemorrhage (38.4%), perforation (36.1%), intractable pain (16.4%) and stenosis (9.1%). Perforation (89.2%) was the most common indication for surgical treatment in the last 10 years. Hemorrhage (4.9%), pain (4.1%) and stenosis (1.8%) were less common. There was no significant difference in surgical morbidity between the two periods. Primary subtotal gastrectomy (SG) accounted for 75.4% of operations in the earlier period, but vagotomy became the main treatment in the last 10 years, including highly selective vagotomy (HSV) (31.9%), and truncal vagotomy with drainage procedure (TV + D) (31.0%). The surgical mortality in the earlier period was 1.3% for SG, 1.8% for TV + D and 16.1% for simple closure. There was no significant change in ulcer location between the two periods. The overall mortality rate was higher in the last 10 years (5.2%) than in the earlier 30 years (2.7%) (p < 0.001). In follow-up studies, the satisfactory rate after operation was similar among patients receiving SG (89.8%), HSV (90.3%) and TV + D (91.1%) between 1977 and 1990.

Experiences in surgical management of cavernous hemangioma of the liver

BACKGROUND/AIMS

Observation is usually recommended for managing patients with cavernous hemangioma of the liver. To assess the indications for surgical management, we make a retrospective analysis.

PATIENTS AND METHODS

There were 14 patients with cavernous hemangioma of the liver who were surgically treated in National Taiwan University Hospital from 1984 to 1993.

RESULTS

The surgical indications included uncertain diagnosis in 10 patients, progressive tumor enlargement in two, symptomatic tumor in one and subcapsular bleeding in one. The tumors were 2-15 cm in diameter and the median was 6 cm. The operation procedures included atypical hepatectomy in 6 patients, lateral segmentectomy in 4, right lobectomy in one, extended right lobectomy in one and open biopsy in two. There was no mortality. Wound infection occurred in one patient. The average blood transfusion was 0.79 unit (range: 0-3 units)(1 unit=500 ml). The postoperative hospital stay was 13.2 days (range: 10-18 days).

CONCLUSION

Surgical management of cavernous hemangioma of the liver is safe.

Clinicopathologic characteristics of Helicobacter pyloric seropositive gastric adenocarcinomas

To compare and characterize retrospectively the clinicopathologic features of gastric cancers with and without previous Helicobacter pylori infection, we determined the preoperative seropositivity of H. pylori in 151 patients who had undergone gastric resection for primary gastric adenocarcinoma between 1988 and 1993. The overall seroprevalence of H. pylori was 60.9%. H. pylori-positive gastric cancers were frequently associated (p<0.05) with macroscopic localized types (Borrmann I and II) in which negative cancer associated with infiltrative types (Borrmann III and IV) and cancer invasion of the duodenum. Multivariate analysis showed that H. pylori seropositivity was not an independent prognostic factor. Pathologic tumor-node-metastases (TNM) stage remained the only prognostic indicator. Our study suggests that H. pylori has a significant impact on the clinically relevant tumor biology of gastric cancer. Investigation along this line is warranted.

Survival after resection of gastric cancer and prognostic relevance of systematic lymph node dissection: twenty years experience in Taiwan

A retrospective study of 954 resectable gastric cancers in a single institute of Taiwan from 1971 to 1990 was performed to evaluate improvements in gastric cancer surgery. The patients were divided into four time periods representing an overall experience of progressive implementation of aggressive resection and increased extent of systematic lymph node dissection. The clinicopathologic data and survival rates were statistically compared and the significance of the extent of resection on survival analyzed. A significant increase in the proportion of upper one-third tumors (from 14.8% to 20.4%) and a decrease in the incidence of intestinal type (73.6% to 41.5%) was found within the overall period. The proportion of patients with early gastric cancer increased from 11.5% to 19.4%. Patients who underwent total gastrectomy and combined visceral resection increased from 13.7% to 27.4% and 19.8% to 41.1%, respectively. An increase of both total dissected lymph node number and the incidence of detected lymph node metastases in early gastric cancer were associated with more extensive lymphadenectomy. An improved 5-year survival rate following aggressive resection was found for all stages except stage IV and T4 lesions, and the surgical mortality decreased from 5.5% to 2.0%. Patients with earlier stage lesions benefited more from radical resection, especially those with stage II and T2 lesions. Systematic lymph node dissection increased the 5-year survival of patients by about 10% for stage III or T3 lesions but not for patients with stage IV or T4 lesions. Multivariate analysis confirmed the significance of the improved technique of lymphadenectomy on the prognosis of gastric cancer following resection in Taiwan.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma of the gastric cardia: prognostic significance of pathologic and treatment factors

The records of 146 patients who had surgery for adenocarcinoma of the gastric cardia between 1977 and 1992 at National Taiwan University Hospital were retrospectively analyzed. The prognostic significance of pathologic and surgical treatment factors was examined by log rank test and stepwise regression procedures. The overall 2-year and 5-year survival rates were 40.2% and 23.7%, respectively. The pathologic factors analyzed included: age, sex, tumor diameter, esophageal invasion, pathologic grading, vascular invasion, perineural invasion, depth of invasion, node-status, distant metastasis and number of positive lymph nodes. The surgical treatment factors analyzed included:surgical procedure, region of lymphadenectomy, resection margin and resection status. Resection status was classified into three categories: absolute curative, relative curative and palliative. Univariate analyses showed that esophageal invasion, vascular invasion, depth of invasion, node status, node number, resection margin and resection status were significant prognostic factors. The selected stepwise regression model identified three significant independent factors: node status, resection status and esophageal invasion. Aggressive surgical management, including combined resection and extended lymphadenectomy, may be helpful for patients with adenocarcinoma of the gastric cardia.

Gonadoblastoma and chroiocarcinoma in dysgenic gonads: report of a case

Dysgenetic gonads are well known to be associated with gonadoblastoma and various germ cell tumors, but very rarely with choriocarcinoma. We describe a 16-year-old, phenotypic female patient with a 46XY karyotype who developed gonadoblastoma on the right gonad and choriocarcinoma on the left. There was no co-existence of the two tumor cell types in the same gonad. This case emphasizes the importance of bilateral gonadectomy for "46XY female" patients, as soon as the cytogenetic evidence is known.

Comparison between resectable gastric adenocarcinomas seropositive and seronegative for Helicobacter pylori

The preoperative seropositivity of Helicobacter pylori was determined in 128 patients who had undergone gastrectomy for primary gastric adenocarcinoma during the past 5 years. The overall seroprevalence of H. pylori was 64 per cent. Gastric cancers positive for H. pylori were associated with tumours located in the lower third of the stomach which were of localized type (Borrmann I and II) (P < 0.05), but not with age, sex, blood type, tumour size, invasion depth, lymph node metastases, histological type, DNA ploidy or type of surgery. The cumulative 5-year survival curves after surgical resection were significantly better in patients who were positive for H. pylori. Multivariate analysis revealed that seropositivity for H. pylori was not an independent prognostic factor. Pathological tumour node metastasis staging was the only prognostic indicator. Better prognosis for those with H. pylori-seropositive gastric cancer may be attributed to the more advanced stage of H. pylori-seronegative gastric cancers. The potential role of H. pylori in gastric cancer carcinogenesis and its biological significance warrant further investigation.

Surgical treatment of gastric adenocarcinoma: the role of lymph node dissection

In this retrospective study, 652 patients who had curative resections for gastric cancer from 1977 to 1991 were reviewed to evaluate improvements in gastric cancer surgery and the influence of the extent of lymphadenectomy on survival. The patients were grouped into three time periods: 1977 to 1981, 1982 to 1986 and 1987 to 1991. The percentage of patients with early gastric cancer increased from 17.7% during 1977 to 1981, to 24.3% during 1987 to 1991. The average number of dissected lymph nodes was 7.5 +/- 8.1 during 1977 to 1981 and 16.4 +/- 10.3 during 1987 to 1991, when more radical lymphadenectomy was adopted. Total gastrectomies increased from 10.9% to 25.9% in the same time periods while combined visceral resections increased from 26.7% to 38.1%. Operative mortality decreased from 5.0% to 1.7%. The overall 5-year survival rate increased from 34.8% to 59.4%. In subgroup analysis, significant improvement of the 5-year survival rate was noted in the following groups: patients with stage I, II and III tumors but not stage IV; both proximal and distally located tumors; tumors with or without lymph node metastases; T1 and T2 but not in T3 and T4 (cancer invasion beyond the serosa). The decreased surgical mortality in recent years suggests that curative resection with extensive lymph node dissection can now be safely performed. Radical gastrectomy with extended lymphadenectomy may be adopted in gastric cancer resection for better control of regional disease.

Lymph node metastases in gastric cancer: significance of positive number

To investigate the significance of the number of node metastases in gastric cancer and its relationship to traditional anatomical classification, 305 patients who underwent a radical gastrectomy and extended lymphadenectomy (R3/4) with curative intent were reviewed. Lymph node metastases was found in 191 (62.6%) patients. The incidence of lymph node metastases was closely related to the depth of cancer invasion as well as the extent of lymph node group involvement. The frequency of metastases in different lymph node locations was related to the location of the primary tumor. The 3-year survival rates for patients with node involvement and without were 42.1 and 92.3%, respectively. In node number analysis, the distribution of the N1 group and the N4 group involvement was rather characteristic and could be predicted from a node number < 4 or > 12. The predictability of N2 and N3 involvement from node numbers 4-8 and 9-12 was less satisfactory. On the whole, patients with a metastatic node number < 4 could be considered to be N1 and had a relative good prognosis. Patients with node number 4-10 could be considered as N2 and > 10 as an incurable disease with distant metastases. Both had a poor prognosis. The data suggest that lymph node number represents the biologic behavior of cancer instead of the anatomic consideration of conventional N stage. The number of metastatic lymph node number is a good prognostic indicator with similar predicting power as the conventional node stage.

Focused image recovery from two defocused images recorded with different camera settings

Two new methods are presented for recovering the focused image of an object from only two blurred images recorded with different camera parameter settings. The camera parameters include lens position, focal length, and aperture diameter. First a blur parameter sigma is estimated using one of our proposed depth-from-defocus methods. Then one of the two blurred images is deconvolved to recover the focused image. The first method is based on a spatial domain convolution/deconvolution transform. This method requires only the knowledge of sigma of the camera's point spread function (PSF). It does not require information about the actual form of the camera's PSF. The second method, in contrast to the first, requires full knowledge of the form of the PSF. As part of the second method, we present a calibration procedure for estimating the camera's PSF for different values of the blur parameter sigma. In the second method, the focused image is obtained through deconvolution in the Fourier domain using a Wiener filter. For both methods, the results of experiments on actual defocused images recorded by a CCD camera are given. The first method requires much less computation than the second method. The first method gives satisfactory results for up to medium levels of blur and the second method gives good results for up to relatively high levels of blur.

An uncommon cause of biliary obstruction (Mirizzi syndrome): report of five cases

Mirizzi syndrome is a rare form of common hepatic duct obstruction resulting from an inflammatory response secondary to a gallstone impacted in the cystic duct or neck of the gallbladder. Herein, we report five patients with this syndrome. Clinically, all patients had prominent jaundice. Ultrasound examination showed a large stone in the neck of the gallbladder. Endoscopic retrograde cholangiopancreaticography demonstrated a filling defect in the biliary tract the cystic duct level. Four patients possessed cholecystobiliary fistulas. Two patients also had common bile duct stones. Operations included simple cholecystectomy in one patient, and partial cholecystectomy with choledochoplasty with the use of gallbladder flap and T-tube insertion in the other four patients. All patients were uneventfully discharged. If a patient has clinical obstructive jaundice, a huge stone encased in the neck of the gallbladder and a filling defect of the biliary tract at the cystic duct level shown on a cholangiogram, Mirizzi syndrome must be considered. A cholecystobiliary fistula will probably be present if the cholangiogram further reveals an excavated filling defect or a block of the common duct; in this case, partial cholecystectomy and choledochoplasty with a gallbladder flap is the treatment of choice. Mirizzi syndrome is a contraindication for laparoscopic cholecystectomy which can easily result in common duct injury.

Can cecal diverticulitis be differentiated from acute appendicitis?

Cecal diverticulitis is a rare disease entity, the diagnosis of which remains a difficult problem. The clinical picture of cecal diverticulitis is almost indistinguishable from acute appendicitis. We reviewed 11 cases of pathologically documented cecal diverticulitis who underwent treatment from May 1981 to April 1992. They were diagnosed incorrectly as acute appendicitis, ruptured appendicitis or appendiceal abscess prior to operative intervention. Thirty patients diagnosed correctly with acute appendicitis from March 1992 to April 1992 were included for a comparative study. We found that cecal diverticulitis presented with a longer duration of symptoms, initial pain over the right lower quadrant of the abdomen, older age, less migration of pain, nausea, vomiting, fever and leukocytosis, and an incidence of Alvarado's score > or = 7 than acute appendicitis.

Therapeutic effect of liver resection in patients with metastatic liver tumors

Thirty-five hepatectomies for metastatic liver malignancy were performed from January 1986 to July 1992 at the National Taiwan University Hospital. Twenty-six of them were of colorectal origin and nine were of other origins. We analyzed the risk factors for recurrence and survival rate after hepatectomy of colorectal origin under curative intention with both univariate and multivariate analysis. The calculated median disease free interval after hepatectomy was 11 months (recurrence rate 65% in one year and 85% in two years). The median survival rate was 24 months (calculated one-year survival 86%, two-year survival 41%). In univariate analysis, the number of metastatic lesions and operation procedures significantly affect the recurrence rate (p = 0.033 and p = 0.042, respectively). In survival univariate analysis, only a safety margin > 1 cm and age > 50 years had significant benefit (p = 0.0014 and p = 0.045, respectively). By multivariate analysis, only solitary metastasis was beneficial to the recurrence rate (p = 0.013), an age > 50 years had a borderline beneficial effect to the recurrence rate (p = 0.052), while earlier liver stage, older age, larger safety margin and minor operative procedures positively affected the survival rate (p = 0.039, 0.018, 0.034 and 0.017, respectively). As the sample number was small, it was hard to draw any conclusions for metastatic liver tumors of other origins. The complication rate (5/35) and mortality rate (1/35) of hepatectomy were low. We concluded that for selected cases of metastatic hepatic malignancy, especially from colorectal cancer, hepatectomy is a promising treatment of choice.

Is previous abdominal surgery a contraindication to laparoscopic cholecystectomy?

Previous abdominal surgery has been reported as a relative contraindication to laparoscopic cholecystectomy. An analysis of 193 laparoscopic cholecystectomies was undertaken to determine whether this relative contraindication led to increased morbidity, an increased rate of conversion to open cholecystectomy, or longer operating time. The results of 55 patients who had previous abdominal surgery were compared with those of 138 patients without previous abdominal surgery. Morbidity, conversion rate, and operating time were not increased in patients with previous abdominal surgery. We found both previous upper and previous lower abdominal surgery to be risk for laparoscopic cholecystectomy. Laparoscopic cholecystectomy can be performed safely in patients with previous abdominal surgery if we (1) use the cutdown technique initially, (2) dissect the adhesion before the upper midline port is inserted, (3) retrogradely dissect the gallbladder from the liver bed, and (4) divide the cystic artery and duct last.

Secular changes in the clinical manifestation and pathologic pattern of early gastric cancer in Taiwan

To investigate whether there has been a time trend change in the percentage of early gastric cancer to gastric cancer and the clinicopathologic features of early gastric cancer in Taiwan, we reviewed 208 patients diagnosed between 1964 and 1992. Patients were divided into group I from 1964-1980 (n = 106) and group II from 1981-1992 (n = 102). The percentage of early gastric cancer among total gastric resections in group II (14.7%) did not differ from group I (12.7%; p = 0.19). Epigastralgia (58.2%) was the most common complaint; 11.8% (12/102) of cancers in group II were incidentally detected by endoscopy. Endoscopy provided a better diagnostic aid than did radiology. Tumors were frequently located in the antrum (50.9%) with a mean diameter of 2.8 cm. Small cancers of less than 1 cm in diameter were more prevalent in group II (37.3%) than group I (10.4%; p < 0.001). Cancers of the elevated type (17.8%) were uncommon in contrast to depressed ones (82.2%; p < 0.001). The frequency of mucosal carcinoma (51.0%) was similar to submucosal carcinoma (49.0%). Mucosal carcinoma had less lymph node metastases (3.1%) than submucosal carcinoma (12.2%; p < 0.05) with an overall frequency of metastases of 7.5% (14/186). The five-year survival rate of group I (91.7%) was not statistically different from group II (94.6%). We concluded that, except for the symptomatology and the ability to diagnose, the clinicopathologic features of early gastric cancer were similar between these two time periods. Repeated investigation of suspicious lesions and endoscopic screening on asymptomatic subjects may increase the rate of detection and thus guarantee a favorable outcome.

Somatostatin-containing carcinoid tumor of the duodenum in neurofibromatosis: report of a case

We report a case of von-Recklinghausen's disease presenting with obstructive jaundice and found to have a somatostatin-containing carcinoid tumor in the papilla of Vater and a small neurofibroma in the duodenum. A 42-year-old woman with von-Recklinghausen's disease presented with intermittent jaundice, pruritus, and mild steatorrhea of a two-year duration. Abdominal ultrasonography and computed tomography showed dilated intrahepatic ducts, common bile duct and pancreatic ducts. Duodenoscopy showed a tumor at the papilla of Vater, but a preoperative biopsy failed to provide a definite diagnosis. Laparotomy revealed a yellowish tumor at the papilla of Vater and another nodule on the mesenteric side of the second section of the duodenum. Microscopically, the tumor at the papilla of Vater was found to be a somatostatin-containing carcinoid tumor. The small nodule on the mesenteric side was a neurofibroma. The jaundice, pruritus and steatorrhea disappeared after surgery.

[Computed tomography of gastric carcinoma using water as a contrast agent]

To overcome the problem of poor mixing of gastrointestinal tract contents with a diluted iodinated contrast agent in abdominal computed tomography, pure water was adopted as an oral contrast agent. In 25 cases of clinically suspected gastric carcinoma, a subsequent pathological examination revealed six cases of early gastric cancer and 19 cases of advanced gastric cancer. We performed CT of the stomach using the following revised procedure: patients were given 600-1000 mL of water by mouth after an intramuscular dose of Buscopan to distend and immobilize the stomach. Gastric mucosal enhancement and the poorer enhanced submucosal layer were demonstrated by a bolus intravenous injection of iodine-containing contrast medium using an automatic injector synchronized with the CT machine. Based on abnormal gastric wall thickening and the abnormal mural enhancement patterns, an accuracy of 96% was attained in differentiating early gastric cancer from advanced gastric cancer, but the detection rates for extragastric invasion, gastric ulcers and lymphadenopathy were 67%, 43% and 63%, respectively. CT staging of gastric cancer was 72%, and was especially accurate for stages I and IV. Water as oral contrast agent for CT of the GI tract was readily accepted by patients and caused no side effects. Using water as an oral contrast for gastric CT is of great help in staging gastric cancer.

Distributional pattern of diverticular disease of the colon in Taiwan

From May 1981 to October 1991, 66 patients with diverticular disease of the colon were analyzed retrospectively. Data were obtained from medical records. There were 29 men and 37 women, ranging in age from 32 to 85 years, with a mean age of 58.7 years. Forty-nine patients had a singular site of distribution in the diverticulum, and 17 patients had more than two sites of distribution in the diverticula. The locations of the diverticular disease were sigmoid colon (45.4%), ascending colon (36.4%), cecum (33.3%), descending colon (18.2%), transverse colon (12.1%) and rectum (1.5%). The left-sided lesions (46.9%) were approximately equal to the right-sided lesions (43.9%).

Carcinoma of the ampulla of Vater: long-term survival after surgical treatment

Ninety-one patients were identified as having carcinoma arising from the ampulla of Vater. Radical pancreaticoduodenectomy, using either a standard or pylorus-preserving method, was performed in 69 consecutive patients over a 30-year period. Frequent clinical findings included jaundice (84%), a weight loss of more than 10% of the body weight (75%), abdominal pain (59%), chills and fever (52%), pruritus (48%) and a palpable gallbladder (38%). Acute pancreatitis was present in 10%. Postoperative mortality was 11.6%. Surgical mortality was 23.1% from 1962 to 1971 and 12.5% from 1972 to 1981, but was reduced to 6.3% from 1982 to 1991. Surgical mortality was primarily due to pancreaticojejunostomy leaks. The five-year survival rate was 52% and the 10-year rate was 50%. Radical pancreaticoduodenectomy for ampullary carcinoma has a low mortality and should remain the procedure of choice for ampullary carcinoma.

Liver resection for hepatic metastasis from colorectal carcinoma

One hundred and eighteen patients who suffered from metastatic liver tumors from colorectal carcinoma during the period from January 1980 to June 1991 at the National Taiwan University Hospital were retrospectively reviewed. The modes of treatment included hepatic resection (n = 18), transarterial embolization (TAE, n = 17), chemotherapy only (C/T, n = 36), and no treatment (n = 47). In the 18 patients who underwent hepatic resection during the last 10 years, the types of surgery included: wedge resection (n = 8), segmentectomy (n = 2), right hepatic lobectomy (n = 5), left hepatic lobectomy (n = 2) and extended right hepatic lobectomy (n = 1). There were no operative mortalities in this series. The overall three-year actuarial survival rate of the resection group was 57.5%. It was better than that of the TAG group (17%, p < 0.05). For a solitary tumor, the three-year actuarial survival rate rose to 64% in the resection group. There were no three-year survivors in the nonsurgical solitary tumor group. This experience defends aggressive surgical treatment of resectable hepatic metastatic liver cancer from colorectal carcinoma as a safe procedure which is able to prolong a patient's life.

Transient hyperprolactinemia in gonadotropin-stimulated cycles for in vitro fertilization and its effect on conception

The significance of transiently increased serum prolactin (PRL) levels on pregnancy rates in vitro fertilization (IVF) is unknown. The aim of this study was to evaluate PRL levels in IVF patients who conceived and in matched controls who did not. Ten IVF cycles resulting in pregnancy and forty nonpregnant cycles were compared. Prolactin was measured before ovarian stimulation with gonadotropins and estradiol (E2), progesterone (P) and PRL were measured 36 hours, 12 hours, 10 minutes before and 12 hours after human chorionic gonadotropin (hCG) administration at mid-cycle. Serum PRL levels at various time were not significantly higher in the nonpregnant women than in the pregnant women. Twelve hours before hCG, P levels were significantly higher in the nonpregnant women than in the pregnant women (1.5 +/- 0.2 ng/ml [mean +/- standard error] and 0.9 +/- 0.3 ng/ml, respectively; P < 0.05). All women had transient hyperprolactinemia for one to three times during ovarian hyperstimulation. There was no correlation between PRL and E2 in either group. These results do not support the treatment of transient hyperprolactinemia with dopamine agonists in IVF patients.

Estradiol administered in a percutaneous gel for the prevention of postmenopausal bone loss

Sixty-one postmenopausal women were randomized into 3 groups. Two groups of women were treated with estrogen replacement therapy (ERT) by percutaneous administration of estradiol gel at a dosage of 1.25 g and 2.5 g, respectively. The third group of women, receiving no treatment except placebo, was studied concurrently as a control group. Bone mineral density (BMD) was measured by quantitative computed tomography (QCT) in the vertebrae from T12-L3 and hormones (E1, E2, FSH, LH and testosterone) were determined by radioimmunoassay at baseline, then at 6 monthly intervals thereafter. One year of the study has been completed thus far. The results of this study indicate that: (1) loss of BMD in the control group was observed significantly only in surgical menopausal women and no significant loss of BMD was observed in women receiving ERT treatment regimens; (2) decrease of E1 in control group and increase of E1 in the treatment group were both significant. These data suggest that percutaneous ERT may be used in prevention of postmenopausal bone loss, particularly in surgical menopausal women and the increased E1 may play a beneficial role in inhibiting loss of bone mass and relieving menopausal syndrome. Different dosages of estradiol gel which did not create any significant difference between the 2 treatment groups, need a longer period of follow-up.

Intraoperative irrigation of the colon and primary anastomosis: report of three cases

Three male patients with obstructive left-sided colonic lesions received intraoperative irrigation of the colon and primary anastomosis after resection of the lesions. Their postoperative courses were smooth except for one patient with mild wound infection. Intraoperative irrigation of the colon is an effective method of facilitating primary anastomosis in the management of obstructive left-sided colonic lesions.

Transcatheter control of intractible gastrointestinal bleeding

A series of 23 patients with intractible gastrointestinal (GI) bleeding were managed by the transcatheter method. The series included 5 with hemobilia, 8 with upper GI (UGI) bleeding, 5 with lower GI (LGI) bleeding and 5 with variceal bleeding. The etiology of the hemobilia was surgery, or percutaneous transhepatic cholangiography and drainage (PTCD) complicated by various degrees of biliary tract infection. The causes of UGI bleeding included erosive gastritis, gastric and duodenal ulcers, and traumatic duodenal laceration. All 5 LGI bleedings were due to ischemic colitis and all 5 variceal bleedings were due to hyperdynamic portal hypertension from arterio-portal (A-P) shunting for hepatocellular carcinomas (HCC). Intra-arterial vasopressin infusion was performed on 17 (4, hemobilia; 8, UGI; and 5 LGI bleeding) of these 23 cases as initial management. The success rate for vasopressin in hemobilia, UGI and LGI bleeding was 75% (3/4), 38% (3/8), and 60% (3/5), respectively. The overall initial success rate of vasopressin was 52% (9/17). The relatively poor success rate of vasopressin infusion for UGI bleeding was due to ulcers and laceration. The incidence of rebleeding for vasopressin infusion was 22% (2/9) including one case each of UGI and LGI bleeding. Three patients (1 hemobilia and 2 UGI bleeding) among these 17 cases underwent transarterial embolization (TAE) after failure of intra-arterial vasopressin infusion. One of these 23 cases with hemobilia underwent TAE for initial transcatheter control of the GI bleeding. Five cases of active esophageal variceal bleeding, caused by A-P shunting in HCC, were all successfully controlled by TAE.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular dynamics of water in foods and related model systems: multinuclear spin relaxation studies and comparison with theoretical calculations

A review of recent studies of molecular dynamics of water in foods and model systems is presented, and the theoretical results are compared with experimental data obtained by several techniques. Both theoretical and experimental approaches are discussed for electrolytes, carbohydrates, and food proteins in solution. Theoretical results from Monte Carlo simulations are compared with experimental NMR relaxation data for quadrupolar nuclei such as those of deuterium and oxygen-17. Hydration studies of wheat, soybean, corn, and myofibrillar proteins by multinuclear spin relaxation techniques are discussed, and several new approaches to the analysis of the experimental data are considered. Correlation times of water motions in hydrated food systems are determined from NMR and dielectric relaxation data. The values of the correlation times for dilute solutions of electrolytes and carbohydrates estimated by NMR are in good agreement with those calculated from dielectric relaxation data, but seem to differ significantly from those proposed from Monte Carlo simulations. Several new and important results concerning the hydration of potato and cereal starches are presented, showing the very different hydration behaviors of these two major groups of starches. The combination of molecular dynamics computations with NMR relaxation techniques will hopefully stimulate novel technological developments in food engineering based on such fundamental studies.

Status of hepatitis B virus DNA in hepatocellular carcinoma: a study based on paired tumor and nontumor liver tissues

To investigate the hepatitis B virus (HBV) DNA status in the liver when hepatocellular carcinoma (HCC) has developed, 35 paired nontumorous and tumorous liver tissues from 27 hepatitis B surface antigen (HBsAg)-seropositive and 8 HBsAg-negative patients with HCC were studied by Southern blot analysis. The hybridization patterns of HBV DNA were different in the nontumor and tumor parts in 26 (96.3%) of the 27 HBsAg-positive patients. In the nontumor parts, integration of HBV DNA into the host genome was significantly less when compared to the tumor parts (15/27 vs. 25/27, P less than 0.05), whereas free replicative viral forms were significantly more frequent (17/27 vs. 7/27). The integrated HBV DNA in the nontumor parts showed discrete band patterns in the majority of cases (13/15). Hepatitis B e antigen (HBeAg) was significantly associated with the expression of free replicative forms of HBV DNA in the tumor tissues. An integrated HBV DNA sequence was detected in the tumor part of one HBsAg-negative patient, but not in her nontumor counterpart. Our observation that discrete integrated HBV DNAs are present in the nontumor part, representing subclinical clonal expansion that precedes the development of HCC, suggests the risk of future new tumor growth from these cell clones.

Intratumor injection of absolute ethanol under ultrasound guidance for the treatment of small hepatocellular carcinoma

For the treatment of small hepatocellular carcinoma, intratumor injection of absolute ethanol under ultrasound guidance was performed in 27 tumors in 23 patients, with a tumor diameter of between 1.0 and 3.3 cm. The initially elevated serum alpha-fetoprotein levels in 15 patients decreased during treatment, with 13 returning to normal after this regimen. In the 6 patients who finally received surgical resection, 4 had complete necrosis of the tumor, while the other 2 had a small peripheral residual cancer nest. In the remaining non-resected 17 cases, follow-up CT, multiple biopsies and angiography revealed evidence of viable tumor in only 3 cases. After additional ethanol injections, these 3 cases were successfully treated. Inhomogeneous distribution of the injected ethanol and difficulty in identifying the tumor after previous injections accounted for the incomplete necrosis of the tumor. To cope with these problems, a steel coil was implanted in the tumor before treatment, and a needle with multiple side holes was used in the last 3 cases, with satisfactory results. Ethanol injection is promising and may even be curative in the treatment of small hepatocellular carcinoma.

Small hepatocellular carcinoma: intratumor ethanol treatment using new needle and guidance systems

Intratumor injection of absolute ethanol to treat small hepatocellular carcinoma sometimes results in incomplete necrosis of the tumor. Causes of this include inhomogeneous distribution of the ethanol and difficulty in identifying the tumor after previous ethanol injections. To solve these problems, the authors designed a multiple-side-hole needle for ethanol injection and implanted one or more small steel coils into the tumor before treatment to serve as a landmark. Six patients thus treated all showed adequate necrosis on follow-up computed tomography, biopsy, and angiography studies; initially elevated serum alpha-fetoprotein levels present in five patients were decreased. A resected surgical specimen obtained in one patient showed extensive necrosis of the tumor as well as of the surrounding healthy liver; only a small locus of equivocally viable cancer cells remained in the tumor margin.

Histologic assessment of resected hepatocellular carcinoma after transcatheter hepatic arterial embolization

Ten cases of large hepatocellular carcinoma (HCC) (largest diameter, 6.5-15 cm) were surgically resected from 3 to 19 days after transcatheter hepatic arterial embolization (TAE) for histologic assessment of the effectiveness. Another two patients, including one with a small HCC (3.5 X 3 X 3 cm) who died of complications, were also studied. The patients' ages ranged from 20 to 64 years, 11 were men and 1 was a woman, and all positive for serum hepatitis B surface antigen. All 11 cases with large HCC were symptomatic before the HCC was clinically diagnosed. Alpha-fetoprotein levels were elevated in ten cases but immediately dropped to normal levels after TAE and resection in eight cases. An effective massive tumor coagulative necrosis of 99% already occurred 3 days after TAE. A necrosis involving more than 95% of the whole tumor mass was demonstrated in eight cases: one was a large HCC taken from an autopsy specimen, and TAE was done three times. This strongly indicates the effectiveness of TAE on the destruction of HCC. However, the presence of viable residual tumors in 11 cases also strongly argues for the necessity for surgical resection whenever it is possible. The failure of a complete necrosis was related to the extracapsular extension, liver invasion, satellite nodules, and portal vein involvement, and probably related to collateral and portal vein blood supply.