Cortical mapping of gait in humans: a near-infrared spectroscopic topography study

While we have a fair understanding of how and where forelimb-hand manipulative movements are controlled by the neocortex, due to functional imaging studies, we know little about the control of bipedal movements such as walking because of technical difficulties. We succeeded in visualizing cortical activation patterns of human gait by measuring relative changes in local hemoglobin oxygenation using a recently developed near-infrared spectroscopic (NIRS) topography technique. Walking activities were bilaterally associated with increased levels of oxygenated and total hemoglobin in the medial primary sensorimotor cortices and the supplementary motor areas. Alternating foot movements activated similar but less broad regions. Gait imagery increased activities caudally located in the supplementary motor areas. These findings provide new insight into cortical control of human locomotion. NIRS topography might be also useful for evaluating cerebral activation patterns during pathological gait and rehabilitative intervention.

Standard steroid treatment for autoimmune pancreatitis

OBJECTIVE

To establish an appropriate steroid treatment regimen for autoimmune pancreatitis (AIP).

METHODS

A retrospective survey of AIP treatment was conducted in 17 centres in Japan. The main outcome measures were rate of remission and relapse.

RESULTS

Of 563 patients with AIP, 459 (82%) received steroid treatment. The remission rate of steroid-treated AIP was 98%, which was significantly higher than that of patients without steroid treatment (74%, 77/104; p<0.001). Steroid treatment was given for obstructive jaundice (60%), abdominal pain (11%), associated extrapancreatic lesions except the biliary duct (11%), and diffuse enlargement of the pancreas (10%). There was no relationship between the period necessary to achieve remission and the initial dose (30 mg/day vs 40 mg/day) of prednisolone. Maintenance steroid treatment was given in 377 (82%) of 459 steroid-treated patients, and steroid treatment was stopped in 104 patients. The relapse rate of patients with AIP on maintenance treatment was 23% (63/273), which was significantly lower than that of patients who stopped maintenance treatment (34%, 35/104; p = 0.048). From the start of steroid treatment, 56% (55/99) relapsed within 1 year and 92% (91/99) relapsed within 3 years. Of the 89 relapsed patients, 83 (93%) received steroid re-treatment, and steroid re-treatment was effective in 97% of them.

CONCLUSIONS

The major indication for steroid treatment in AIP is the presence of symptoms. An initial prednisolone dose of 0.6 mg/kg/day, is recommend, which is then reduced to a maintenance dose over a period of 3-6 months. Maintenance treatment with low-dose steroid reduces but dose not eliminate relapses.

Randomized phase III study of cisplatin plus irinotecan versus carboplatin plus paclitaxel, cisplatin plus gemcitabine, and cisplatin plus vinorelbine for advanced non-small-cell lung cancer: Four-Arm Cooperative Study in Japan

BACKGROUND

To compare the efficacy and toxicity of three platinum-based combination regimens against cisplatin plus irinotecan (IP) in patients with untreated advanced non-small-cell lung cancer (NSCLC) by a non-inferiority design.

PATIENTS AND METHODS

A total of 602 patients were randomly assigned to one of four regimens: cisplatin 80 mg/m(2) on day 1 plus irinotecan 60 mg/m(2) on days 1, 8, 15 every 4 weeks (IP) carboplatin AUC 6.0 min x mg/mL (area under the concentration-time curve) on day 1 plus paclitaxel 200 mg/m(2) on day 1 every 3 weeks (TC); cisplatin 80 mg/m(2) on day 1 plus gemcitabine 1000 mg/m(2) on days 1, 8 every 3 weeks (GP); and cisplatin 80 mg/m(2) on day 1 plus vinorelbine 25 mg/m(2) on days 1, 8 every 3 weeks (NP).

RESULTS

The response rate, median survival time, and 1-year survival rate were 31.0%, 13.9 months, 59.2%, respectively, in IP; 32.4%, 12.3 months, 51.0% in TC; 30.1%, 14.0 months, 59.6% in GP; and 33.1%, 11.4 months, 48.3% in NP. No statistically significant differences were found in response rate or overall survival, but the non-inferiority of none of the experimental regimens could be confirmed. All the four regimens were well tolerated.

CONCLUSION

The four regimens have similar efficacy and different toxicity profiles, and they can be used to treat advanced NSCLC patients.

No-mortality liver resection for hepatocellular carcinoma in cirrhotic and noncirrhotic patients: is there a way? A prospective analysis of our approach

BACKGROUND

Low resectability rates and significant morbidity and mortality rates often make surgery for hepatocellular carcinomas (HCCs) unfeasible.

HYPOTHESIS

Our policy for surgical treatment of cirrhotic and noncirrhotic patients with HCC is adequate and safe.

DESIGN

Prospective validation cohort study.

SETTING

University hospital.

PATIENTS

One hundred seven consecutive patients with HCCs. Associated cirrhosis was present in 64 (59.8%), and only 7 (6.5%) had normal livers.

INTERVENTIONS

The presence of ascites, serum bilirubin level, and indocyanine green retention rate at 15 minutes were considered when selecting patients for surgery. Preoperative recovery of liver function was achieved with portal venous branch embolization, liver volumetry, bed rest, and control of serum aminotransferase levels. The surgical techniques mainly involved bloodless dissection using intraoperative ultrasonography and intermittent warm ischemia. The main perioperative care regimen was fresh frozen plasma infusion and strict limitation of blood transfusion.

MAIN OUTCOME MEASURES

The 30-day postoperative mortality and morbidity rates.

RESULTS

All the patients underwent surgery (37 major resections, 45 segmentectomies, and 25 limited resections), with no 30-day postoperative mortality, overall morbidity of 26.2%, and no major complications. Multiple logistic regression analysis revealed that only the type of operation was associated with a significantly higher morbidity risk (P = .05).

CONCLUSION

With high resectability, low morbidity, and no mortality, our policy represents a solution to the drawbacks of surgical resection for treatment of HCCs, especially in patients with associated liver cirrhosis.

Rapid pulsed-field gel electrophoresis protocol for subtyping of Campylobacter jejuni

We developed a rapid pulsed-field gel electrophoresis (PFGE) protocol for subtyping Campylobacter isolates based on the standardized protocols used by PulseNet laboratories for the subtyping of other food-borne bacterial pathogens. Various combinations of buffers, reagents, reaction conditions (e.g., cell suspension concentration, lysis time, lysis temperature, and restriction enzyme concentration), and electrophoretic parameters were evaluated in an effort to devise a protocol that is simple, rapid, and robust. PFGE analysis of Campylobacter isolates can be completed in 24 to 30 h using this protocol, whereas the most widely used current protocols require 3 to 4 days to complete. Comparison of PFGE patterns obtained in six laboratories showed that subtyping results obtained using this protocol are highly reproducible.

Accurate preoperative evaluation of liver mass lesions without fine-needle biopsy

Fine-needle biopsy (FNB) is associated with problems, such as tumor seeding, which are probably underestimated. The aim of this study was to validate prospectively the accuracy of our diagnostic work-up without FNB, for defining indications for surgery in a cohort of patients with focal liver lesions (FLLs). Between January 1997 and December 1998, 160 consecutive patients carrying 225 FLLs admitted to our department were evaluated prospectively. Preoperative diagnoses were established by means of clinical histories, serum tumor marker levels, ultrasonography, and spiral computed tomography (CT). Angiography, magnetic resonance imaging (MRI), and Lipiodol-CT were performed when it was considered necessary to plan the surgical strategy. All the patients underwent surgery and results of pathological examinations were obtained for all of them. The preoperative diagnoses of 221 of the 225 lesions (98.2%) were confirmed, and the indications for liver resection in 156 of the 160 patients (97.5%) were correct. The respective accuracy, sensitivity, specificity, and positive and negative predictive values were 99.6%, 100%, 98.9%, 99.3%, and 100% for diagnosis of hepatocellular carcinoma (HCC); 99.1%, 100%, 98.8%, 96.9%, and 100% for metastases; 99.6%, 100%, 99.5%, 91%, and 100% for cholangiocellular carcinomas (CCCs); all 100% for mixed HCC-CCCs; and 98.7%, 57.1%, 100%, 100%, and 98.6% for benign tumors. In view of these results, the fact that the real risks of FNB have yet to be established and the possibility that tumor seeding has a major impact on patient prognosis, the use of FNB should be drastically limited.

Periodontal repair in dogs: recombinant human bone morphogenetic protein-2 significantly enhances periodontal regeneration

This study evaluated bone and cementum regeneration following periodontal reconstructive surgery using recombinant human bone morphogenetic protein-2 (rhBMP-2) in six beagle dogs. Surgically created mandibular supraalveolar premolar tooth defects in contralateral jaw quadrants were randomly assigned to receive rhBMP-2 or control vehicle. Clinical defect height was prepared to 5 mm. rhBMP-2 was applied with synthetic bioerodable particles and autologous blood using 20 micrograms rhBMP-2 per 100 microliters implant volume. Flaps were advanced to submerge the teeth and sutured. The dogs were sacrificed 8 weeks postsurgery. Histometric recordings included defect height, height and area of alveolar bone regeneration, height of cementum regeneration, root resorption, and ankylosis. Group means, standard deviations, and P values are shown (Student t test; n = 6). Histometric defect height for rhBMP-2 and control defects was 3.7 +/- 0.3 and 3.9 +/- 0.4 mm, respectively (P = 0.446). Height of alveolar bone regeneration amounted to 3.5 +/- 0.6 and 0.8 +/- 0.6 mm for rhBMP-2 and control defects, respectively (P = 0.000). Corresponding values for bone area were 8.4 +/- 4.5 and 0.4 +/- 0.5 mm2, respectively (P = 0.006). Cementum regeneration was observed in all experimental defects (17/17) and in 15 out of 17 controls, averaging 1.6 +/- 0.6 and 0.4 +/- 0.3 mm for rhBMP-2 and control defects, respectively (P = 0.005). Small amounts of root resorption were seen in rhBMP-2 defects, whereas controls exhibited substantial resorption (0.2 +/- 0.1 and 1.1 +/- 0.3 mm, respectively; P = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized comparison of ultrasonic vs clamp transection of the liver

HYPOTHESIS

Hepatic parenchymal transection is a technical priority in liver surgery. The use of an ultrasonic dissector for hepatectomy may result in less blood loss than conventional clamp crushing.

DESIGN

Randomized controlled trial.

SETTING

University teaching hospital.

PATIENTS

The 132 patients scheduled to undergo partial hepatectomies were randomly assigned to receive hepatic transection by ultrasonic dissector or by clamp crushing (66 patients by each method).

INTERVENTIONS

All resections were performed with inflow occlusion and were guided ultrasonographically. Hepatectomies were graded according to a predefined system based on 6 criteria (blood loss, transection time, technical error, surgical margin, landmark appearance, and postoperative morbidity), each with 3 scores (lower scores indicating higher quality).

MAIN OUTCOME MEASURES

Blood loss and hepatectomy grade.

RESULTS

No difference was found between the ultrasonic and clamp groups in median blood loss (515 mL [range, 15-2527 mL] vs 452 mL [range, 17-1912 mL]; P =.63), transection time (61 minutes [range, 16-177 minutes] vs 54 minutes [range, 7-205 minutes]; P =.58), or transection speed (1.1 cm(2)/min [range, 0.4-4.0 cm(2)/min] vs 1.0 cm(2)/min [range, 0.4-3.0 cm(2)/min]; P =.90). Ultrasonic dissection caused more frequent histologically proven tumor exposure at the surgical margin (9 vs 3 patients; P =.09), incomplete appearance of landmark hepatic veins on the cut surface after anatomical resection (12 vs 4 patients; P =.03), and postoperative morbidity (20 vs 14 patients; P =.32) than did clamp crushing. The hepatectomies with clamp crushing had significantly higher grades than those with ultrasonic dissection (P =.05), as indicated by the lower median sum score (4.0 [range, 0-12] vs 5.0 [range, 0-19]; 95% confidence interval for difference, -2.0 to 0; P =.03). The transection method independently influenced hepatectomy grade (adjusted odds ratio = 3.06; 95% confidence interval, 1.35-6.92; P =.01).

CONCLUSIONS

Ultrasonic dissection offers no reduction in blood loss compared with clamp crushing for transection of the liver. Clamp crushing results in a higher quality of hepatectomy and is therefore the option of choice.

Measurement of liver volume and hepatic functional reserve as a guide to decision-making in resectional surgery for hepatic tumors

The respective volumes of hepatic tumors and nontumorous parenchyma of 50 patients requiring hepatectomy of more than one segment of Healey for tumor removal were measured using computed tomography (Vol-CT). The volume estimated by Vol-CT was found to correlate with the real weight resected (P < .0001) with a mean absolute error of 64.9 mL. The ratio of the nontumorous parenchymal volume of the resected liver to that of the whole liver (R2) in 15 patients who underwent right or extended right hepatic lobectomy was 43% +/- 15%. Eight of 15 patients with R2s < 60% underwent the procedures without right portal vein embolization (PE). The other seven with R2s exceeding 60% or an indocyanine green retention rate after 15 minutes (ICG15) of 10% to 20% underwent PE: in six of seven, the nontumorous parenchyma of the right hepatic lobe became atrophic and in all seven, the volume of the remaining left hepatic lobe increased with a decrease in the mean R2 from 62% +/- 14% to 55% +/- 8% (P = .0006). In the remaining 35 who underwent other hepatectomy procedures, R2s also remained <60%. Overall, at surgery, in 27 with normal liver function (ICG15 < 10%), R2s exceeded 60% in one, remained at 50% to 60% in five, and <50% in 21, whereas 23 patients except for one with an ICG15 exceeding 10%, had R2s of <50%. The postoperative serum total bilirubin levels in 84% of the patients remained within the normal range and there was no surgery-related mortality. In conclusion, 1) Vol-CT can accurately assess the extent of liver resection, 2) individuals with normal liver function can undergo resection of up to 60% of the nontumorous parenchyma without the need for PE, and 3) PE can be used to reduce the size of the resected tissue and increase the volume of the remnant liver to approximate the target limits in individuals with large tumors or minimally abnormal liver function.

Advantage of delayed whole-body FDG-PET imaging for tumour detection

Delayed imaging that coincides with the highest uptake of fluorine-18 fluorodeoxyglucose (FDG) by tumour may be advantageous in oncological positron emission tomography (PET), where delineation of metastasis from normal tissue background is important. In order to identify the better imaging protocol for tumour detection, whole-body FDG-PET images acquired at 1 h and 2 h after injection were evaluated in 22 subjects, with a post-injection transmission scan at 90 min for attenuation correction. After visual interpretation, tumour uptake [tumour standardised uptake ratio (SUR)], normal tissue uptake (normal SUR) and tumour to background contrast (tumour SUR/normal tissue SUR) were evaluated in the images acquired at 1 h and at 2 h. Most malignant lesions, including primary lung cancer, metastatic mediastinal lymph nodes and lymphoma lesions, showed higher FDG uptake at 2 h than at 1 h. By contrast, benign lesions, with the exception of sarcoidosis, showed lower uptake of FDG at 2 h than at 1 h. Among normal tissues, the kidney, liver, mediastinum, lung, upper abdomen and left abdomen showed significant falls in FDG uptake from 1 h to 2 h. The lower abdomen, right abdomen and muscles (shoulder and thigh) showed no significant changes. Consequently, malignant lesions of the lung, mediastinum and upper abdomen showed significant increases in tumour to background contrast from 1 to 2 h. Three lesions (two lung cancers and a malignant lymphoma) that were equivocal on 1-h images became evident on 2-h images, changing the results of interpretation. All other malignant lesions were detected on 1-h images, but were clearer, with higher contrast, on 2-h images. Lesion-based sensitivity was improved from 92% (49/53) to 98% (52/53), and patient-based sensitivity from 78% (14/18) to 94% (17/18). It is concluded that delayed whole-body FDG-PET imaging is a better and more reliable imaging protocol for tumour detection.

From tumor biology to clinical Pet: a review of positron emission tomography (PET) in oncology

Cancer cells show increased metabolism of both glucose and amino acids, which can be monitored with 18F-2-deoxy-2-fluoro-D-glucose (FDG), a glucose analogue, and 11C-L-methionine (Met), respectively. FDG uptake is higher in fast-growing than in slow-growing tumors. FDG uptake is considered to be a good marker of the grade of malignancy. Several studies have indicated that the degree of FDG uptake in primary lung cancer can be used as a prognostic indicator. Differential diagnosis of lung tumors has been studied extensively with both computed tomography (CT) and positron emission tomography (PET). It has been established that FDG-PET is clinically very useful and that its diagnostic accuracy is higher than that of CT. Detection of lymph node or distant metastases in known cancer patients using a whole-body imaging technique with FDG-PET has become a good indication for PET. FDG uptake may be seen in a variety of tissues due to physiological glucose consumption. Also FDG uptake is not specific for cancer. Various types of active inflammation showed FDG uptake to a certain high level. Understanding of the physiological and benign causes of FDG uptake is important for accurate interpretation of FDG-PET. In monitoring radio/chemotherapy, changes in FDG uptake correlate with the number of viable cancer cells, whereas Met is a marker of proliferation. Reduction of FDG uptake is a sensitive marker of viable tissue, preceding necrotic extension and volumetric shrinkage. FDG-PET is useful for the detection of recurrence and for monitoring the therapeutic response of tumor tissues in various cancers, including those of the lung, colon, and head and neck. Thus, PET, particularly with FDG, is effective in monitoring cancer cell viability, and is clinically very useful for the diagnosis and detection of recurrence of lung and other cancers.

Activation of the right inferior frontal cortex during assessment of facial emotion

We measured regional cerebral blood flow (rCBF) using positron emission tomography (PET) to determine which brain regions are involved in the assessment of facial emotion. We asked right-handed normal subjects to assess the signalers' emotional state based on facial gestures and to assess the facial attractiveness, as well as to discriminate the background color of the facial stimuli, and compared the activity produced by each condition. The right inferior frontal cortex showed significant activation during the assessment of facial emotion in comparison with the other two tests. The activated area was located within a triangular area of the inferior frontal cortex in the right cerebral hemisphere. These results, together with those of previous imaging and clinical studies, suggest that the right inferior frontal cortex processes emotional communicative signals that could be visual or auditory and that there is a hemispheric asymmetry in the inferior frontal cortex in relation to the processing of emotional communicative signals.

The conservative treatment of complete tears of the anterior cruciate ligament in skeletally immature patients

We describe the results of conservative treatment for complete midsubstance tears of the anterior cruciate ligament (ACL) in 18 skeletally immature patients, followed for a minimum of 36 months. Six patients had an ACL reconstruction during the follow-up period and were assessed immediately before their operation. The average time from initial injury to evaluation was 51 months. All patients had symptoms when reviewed. The modified Lysholm knee score showed one excellent result, one good, eight fair, and eight poor with a mean score of 64.3. Only one patient had returned to her preinjury level of athletics. Secondary meniscal tears were confirmed in six patients, and three more had the clinical signs of a tear at follow-up. Radiological evidence of degenerative changes was found in 11 of the 18 patients. We conclude that the results of non-operative treatment for ACL injuries in this age group are poor and not acceptable.

Immunomodulation by vitamin B12: augmentation of CD8+ T lymphocytes and natural killer (NK) cell activity in vitamin B12-deficient patients by methyl-B12 treatment

It has been suggested that vitamin B12 (vit.B12) plays an important role in immune system regulation, but the details are still obscure. In order to examine the action of vit.B12 on cells of the human immune system, lymphocyte subpopulations and NK cell activity were evaluated in 11 patients with vit.B12 deficiency anaemia and in 13 control subjects. Decreases in the number of lymphocytes and CD8+ cells and in the proportion of CD4+ cells, an abnormally high CD4/CD8 ratio, and suppressed NK cell activity were noted in patients compared with control subjects. In all 11 patients and eight control subjects, these immune parameters were evaluated before and after methyl-B12 injection. The lymphocyte counts and number of CD8+ cells increased both in patients and in control subjects. The high CD4/CD8 ratio and suppressed NK cell activity were improved by methyl-B12 treatment. Augmentation of CD3-CD16+ cells occurred in patients after methyl-B12 treatment. In contrast, antibody-dependent cell-mediated cytotoxicity (ADCC) activity, lectin-stimulated lymphocyte blast formation, and serum levels of immunoglobulins were not changed by methyl-B12 treatment. These results indicate that vit.B12 might play an important role in cellular immunity, especially relativing to CD8+ cells and the NK cell system, which suggests effects on cytotoxic cells. We conclude that vit.B12 acts as an immunomodulator for cellular immunity.

Neural substrates for recognition of familiar voices: a PET study

Identification of familiar people is essential in our social life. We can identify familiar people by hearing their voices as well as by viewing their faces. By measuring regional cerebral blood flow (rCBF) by positron emission tomography (PET), we identified neural substrates for the recognition of familiar voices. The brain activity during discrimination of voices of the subjects' associates and friends from those of unfamiliar people was compared with that during an analogous discrimination of their own voice from unfamiliar voices as well as during vowel discrimination. The left frontal pole, right temporal pole, right entorhinal cortex, and left precuneus were activated to a greater extent during discrimination of familiar voice than during control discriminations, suggesting that these brain regions are involved in the recognition of familiar voices. Furthermore, the adjusted values of rCBF in the left frontal pole and right temporal pole correlated with the number of subjects' correct identification of familiar voices. The present results suggest that these two regions are coactively associated with matching the currently heard voice to familiar voices in one's memory.

A prospective phase II study on photodynamic therapy with photofrin II for centrally located early-stage lung cancer. The Japan Lung Cancer Photodynamic Therapy Study Group

PURPOSE

A phase II study was conducted between June 1989 and February 1992 to evaluate the activity and toxicity of photodynamic therapy (PDT) with photofrin II in centrally located early-stage lung cancer and to determine the complete response (CR) rate as the primary end point.

PATIENTS AND METHODS

Patients had histologically proven lung cancer and endoscopically superficial thickening or small protrusions. All lesions were located in subsegmental or larger bronchi. All patients had a performance status (PS) of 0 to 2 and arterial oxygen pressure tension (PaO2) > or = 60 mm Hg. No lymph node or distant metastases were present. All patients received photofrin II (2 mg/kg) intravenously 48 hours before PDT. Tumor lesions were superficially photoradiated by an argon dye laser or an excimer dye laser.

RESULTS

Of 54 patients with 64 carcinomas, 51 with 61 carcinomas were eligible for toxicity evaluation and 49 with 59 carcinomas were assessable for response. Of the 59 assessable carcinomas, 50 (84.8%; 95% confidence interval, 73.0% to 92.8%) showed a CR after initial PDT. The median duration of CR was 14.0+ months (range, 2.0+ to 32.4+). The multiple regression model indicates that estimated length of longitudinal tumor extent was the only independent prognostic factor for CR (P = .002). Five carcinomas that had a CR had a local recurrence at 6, 10, 12, 16, and 18 months after initial PDT, respectively. Toxicity assessment (World Health Organization [WHO] grade 2) showed transient elevation of ALT (1.9%), pulmonary toxicity (7.7%), and allergic reaction (7.7%), as well as sunburn (1.9%).

CONCLUSION

PDT with photofrin II has an excellent effect on patients with centrally located early-stage lung cancer who have limited tumor invasion extending over a small area (< or = 1 cm).

How should polypoid lesions of the gallbladder be treated in the era of laparoscopic cholecystectomy?

BACKGROUND

Definitive criteria for choosing the most appropriate treatment for each type of polypoid lesion of the gallbladder (PLG) have yet to be established.

METHODS

The shapes, sizes, echo patterns, and echogenicities of PLGs that had been evaluated by means of ultrasonography in 72 patients who had undergone resective surgery were analyzed retrospectively to elucidate the ultrasonic characteristics of polypoid cancers and to establish criteria for selecting the most suitable treatment such as laparoscopic cholecystectomy for each type of PLG.

RESULTS

Histologic examinations showed cholesterol polyps in 47 patients, adenomas in 8, cancers in 16, and an inflammatory polyp in 1. The diameters of 61% of the benign PLGs were less than 10 mm, whereas those of 88% of the cancers were more than 10 mm; 80% of the former were pedunculated and 56% of the latter were sessile. Seven of eight early-stage cancers had diameters less than 18 mm, whereas those of all eight more advanced cancers were greater than 18 mm. Five of the eight early-stage cancers were pedunculated, and six of the eight more advanced cancers were sessile. Cholecystectomy with or without full-thickness dissection were main surgical procedures used to resect benign PLGs and early-stage cancers, whereas cholecystectomy with partial liver resection was used for more advanced cancers. Laparoscopic cholecystectomy was performed in the recent 34 patients, four of whom had early-stage cancers.

CONCLUSIONS

A PLG with a diameter of less than 18 mm is a potential early-stage cancer and therefore can be resected by laparoscopic cholecystectomy with full-thickness dissection. However, when cancer invades the subserosal layer or beyond, a second-look operation is necessary. A PLG with a diameter of greater than 18 mm may be an advanced cancer and should be removed by using cholecystectomy with partial liver resection or a more extended procedure with lymph node dissection.

Effect of mastication on regional cerebral blood flow in humans examined by positron-emission tomography with ¹⁵O-labelled water and magnetic resonance imaging

The interaction between mastication and cerebral blood flow was studied in 12 healthy volunteers (five males and seven females) aged 18-40 years. Positron-emission tomography (PET) autoradiography was carried out after bolus injection of 1.5 GBq H₂¹⁵O (¹⁵O-labelled water) with a half life of 2 min. The PET images were superimposed on magnetic resonance images of each participant. The regional cerebral blood flow images were normalized by the global cerebral blood flow value, and subtraction images (those during gum-chewing minus those during resting) were created and recut at the magnetic resonance image slice positions. Gum specially designed for chewing training was used. Mastication increased regional cerebral blood flow in the primary sensorimotor areas by 25-28%, in the supplementary motor areas and insulae by 9-17%, and in the cerebellum and striatum by 8-11%. These increases demonstrate that chewing activates widespread regions of the brain.

Combination of platelet count and neutrophil to lymphocyte ratio is a useful predictor of postoperative survival in patients with colorectal cancer

Background:

This study investigated the usefulness of a novel inflammation-based prognostic system, named the COP-NLR (COmbination of Platelet count and Neutrophil to Lymphocyte Ratio), for predicting the postoperative survival of patients with colorectal cancer (CRC).

Methods:

The COP-NLR was calculated on the basis of data obtained on the day of admission: patients with both an elevated platelet count (>30 × 10⁴ mm⁻³) and an elevated NLR (>3) were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively.

Results:

Four-hundred and eighty patients were enrolled. Multivariate analysis of clinical characteristics selected by univariate analysis showed that the COP-NLR (1, 2/0) (odds ratio, 0.464; 95% confidence interval, 0.267–0.807; P=0.007) had an association with cancer-specific survival, along with pathology, lymph node metastasis, the serum levels of carcinoembryonic antigen, C-reactive protein and albumin, and the Glasgow Prognostic Score. Kaplan–Meier analysis and log-rank test revealed that the COP-NLR was able to divide such patients into three independent groups (P<0.001).

Conclusion:

The COP-NLR is considered to be a useful predictor of postoperative survival in patients with CRC.

Working memory and prefrontal cortex

Several different types of memory have recently been proposed, some of which are believed to operate within specific areas in the brain. In this article, we will discuss the relationship between the prefrontal cortex and working memory, which is a recently proposed type of short-term memory. The tight relationship between the prefrontal cortex and working memory has been supported by recent human and animal studies. This relationship provides good evidence that a particular type of memory is related to a particular brain structure, and can be used as an important model for understanding the neuronal mechanisms of memory. In this article, we will present a modular model based on recent neurophysiological results and discuss for spatial working memory processes in the prefrontal cortex.

Ca(2+)-independent cell-adhesion activity of claudins, a family of integral membrane proteins localized at tight junctions

In multicellular organisms, various compositionally distinct fluid compartments are established by epithelial and endothelial cellular sheets. For these cells to function as barriers, tight junctions (TJs) are considered to create a primary barrier for the diffusion of solutes through the paracellular pathway [1] [2] [3]. In ultrathin sections viewed under electron microscopy, TJs appear as a series of apparent fusions, involving the outer leaflets of plasma membranes of adjacent cells, to form the so-called kissing points of TJs, where the intercellular space is completely obliterated [4]. Claudins are a family of 16 proteins whose members have been identified as major integral membrane proteins localized exclusively at TJs [5] [6] [7] [8]. It remains unclear, however, whether claudins have the cell-adhesion activity that would explain the unusual intercellular adhesion at TJs. Using mouse L-fibroblast transfectants expressing various amounts of claudin-1, -2 or -3, we found that these claudins possess Ca(2+)-independent cell-adhesion activity. Using ultrathin-section electron microscopy, we observed many kissing points of TJs between adjacent transfectants. Furthermore, the cell-adhesion activity of occludin, another integral membrane protein localized at TJs [9] [10] [11], was negligible when compared with that of claudins. Thus, claudins are responsible for TJ-specific obliteration of the intercellular space.