Long non-coding RNA OIP5-AS1 serves as a competing endogenous RNA to modulate X-linked inhibitor of apoptosis protein expression via adsorbing miR-429 in papillary thyroid cancer

Papillary thyroid cancer (PTC) is currently one of the most common endocrine tumors worldwide. Long non-coding RNA (LncRNA) is a vital regulator in the biological processes of diverse tumors. Hence, this work aimed to clarify the role and mechanism of lncRNA OIP5-AS1 in PTC progression. OIP5-AS1 and miR-429 expression levels in PTC tissues and cells were examined using qRT-PCR. Immunohistochemical staining (IHC) was applied to detect X-linked inhibitors of apoptosis protein (XIAP) expression in PTC tissues. A dual-luciferase reporter gene experiment was employed to validate the relationship for miR-429 and XIAP, miR-429 and OIP5-AS1. The regulatory effects of OIP5-AS1 on PTC cell proliferation, migration, and invasion was detected using the MTT, BrdU, Transwell and Western blot assays. In this work we reported that OIP5-AS1 expression was up-modulated in PTC tissues and cell lines. OIP5-AS1 overexpression enhanced the proliferation and metastasis of PTC cells, but the transfection of miR-429 mimics reversed the functions of OIP5-AS1 on the proliferation, migration, and invasion of PTC cells. Additionally, OIP5-AS1 was identified as a competitive endogenous RNA (ceRNA) that repressed miR-429, thereby increasing the expression level of XIAP. Taken together, the findings confirm that OIP5-AS1 accelerates PTC progression via modulating the miR-429/XIAP axis and imply that OIP5-AS1 is likely to be a therapeutic target for PTC.

Quantum self-contained refrigerator in terms of the cavity quantum electrodynamics in the weak internal-coupling regime

We present two schemes to implement the self-contained refrigerator in the framework of the cavity quantum electrodynamics. The considered refrigerators are composed of three interacting microcavities (or two microcavities simultaneously interacting with one three-level atom) separately coupling to a thermal bath with a certain temperature. Despite the local master equation employed, the proposed analytic procedure shows the perfect thermodynamical consistency. It is also demonstrated that the heat is stably extracted from the lowest temperature bath with a fixed efficiency only determined by the intrinsic properties of the refrigerators, i.e., the frequency ratio of the two cavities in contact with the two higher temperature baths. These two schemes indicate that the system with the weak internal coupling in the infinite dimensional Hilbert space can be used to realize the quantum self-contained refrigerator on the principle completely the same as the original self-contained refrigerator.

Magnetic resonance tumour regression grade and pathological correlates in patients with rectal cancer

BACKGROUND

Evidence to support the specific use of magnetic resonance tumour regression grade (mrTRG) is inadequate. The aim of this study was to investigate the pathological characteristics of mrTRG after chemoradiotherapy (CRT) for rectal cancer and the implications for surgery.

METHODS

Patients undergoing long-course CRT (45-50 Gy plus a booster dose of 4-6 Gy) for mid or low rectal cancer (cT3-4 or cN+ without metastasis) between 2011 and 2015 who had post-CRT rectal MRI before surgery were included retrospectively. Three board-certified experienced radiologists assessed mrTRG. mrTRG was correlated with pathological tumour regression grade (pTRG), ypT and ypN. In a subgroup of patients with mrTRG1-2 and no tumour spread (such as nodal metastasis) on MRI, the projected rate of completion total mesorectal excision (TME) if they underwent transanal excision (TAE) and had a ypT status of ypT2 or higher was estimated, and recurrence-free survival was calculated according to the operation (TME or TAE) that patients had actually received.

RESULTS

Some 439 patients (290 men and 149 women of mean(s.d.) age 62·2(11·4) years) were analysed. The accuracy of mrTRG1 for predicting pTRG1 was 61 per cent (40 of 66), and that for ypT1 or less was 74 per cent (49 of 66). For mrTRG2, these values were 22·3 per cent (25 of 112) and 36·6 per cent (41 of 112) respectively. Patients with mrTRG1 and mrTRG2 without tumour spread were ypN+ in 3 per cent (1 of 29) and 16 per cent (8 of 50) respectively. Assuming mrTRG1 or mrTRG1-2 with no tumour spread on post-CRT MRI as the criteria for TAE, the projected completion TME rate was 26 per cent (11 of 43) and 41·0 per cent (41 of 100) respectively. For the 100 patients with mrTRG1-2 and no tumour spread, recurrence-free survival did not differ significantly between TME (79 patients) and TAE (21) (adjusted hazard ratio 1·86, 95 per cent c.i. 0·42 to 8·18).

CONCLUSION

Patients with mrTRG1 without tumour spread may be suitable for TAE.

Late anastomotic leakage after low anterior resection in rectal cancer patients: clinical characteristics and predisposing factors

AIM

The purpose was to examine the clinical characteristics and predisposing factors of late anastomotic leakage following low anterior resection for rectal cancer.

METHOD

We retrospectively evaluated the clinicopathological features of patients who experienced anastomotic leakage after low anterior resection for rectal cancer. Patients were divided into two groups according to the time to leakage: early leakage (within 30 days postoperatively) and late leakage (after 30 days postoperatively). Clinicopathological characteristics were compared between the two groups.

RESULTS

Anastomotic leakage occurred in 141 patients. Anastomotic leakage was diagnosed at a median of 17 (range 0-886) days postoperatively; 85 (60.3%) and 56 (39.7%) were categorized as the early and late leakage groups, respectively. Radiotherapy (hazard ratio 5.007; 95% CI 2.208-11.354; P < 0.0001) was the only significant independent predisposing factor for late leakage. Diverting stoma did not protect against late leakage. The late leakage group more frequently had the fistula type (46.4% vs. 10.6%; P < 0.001) and less frequently needed laparotomy (55.4% vs. 78.8%; P = 0.001). The rate of long-term stoma over 1 year was greater in the late leakage than the early leakage group (51.8% vs. 29.4%; P = 0.009).

CONCLUSION

Late anastomotic leakages that develop after 30 days following low anterior resection are not uncommon and may be associated with the use of radiotherapy. Late leakage should be a different entity from early leakage in terms of the type of leakage, methods of management and subsequent sequelae.

Prevalence and clinical significance of cellular and acellular mucin in patients with locally advanced mucinous rectal cancer who underwent preoperative chemoradiotherapy followed by radical surgery

AIM

The frequent presence of acellular mucin in specimens showing pathological complete response to preoperative chemoradiotherapy (CRT) and the poor response to preoperative CRT in mucinous rectal cancer have been reported. However, the prevalence and prognostic significance of cellular and acellular mucin have not been evaluated in resected specimens from patients with mucinous rectal cancer who undergo preoperative CRT.

METHOD

We retrospectively evaluated the clinicopathological features and prognostic significance of mucin in resected specimens from 59 consecutive patients with mucinous rectal cancer who underwent long-course CRT followed by resection between January 2000 and December 2009. Patients were categorized according to the presence of mucin, as identified by pathological analysis. The clinicopathological findings and oncological results were compared.

RESULTS

Mucin was identified in 25 of 59 patients with mucinous rectal cancer (42.4%). Mucin was more frequent in men (hazard ratio = 23.94, 95% confidence interval = 1.875-305.504, P = 0.015) and in specimens showing a good tumour response grade (hazard ratio = 64.26, 95% confidence interval = 6.940-595.045, P < 0.001). With a median follow-up of 67.7 (range 8.6-133.2) months, the 5-year overall survival (60.7% without mucin vs 51.4% with mucin, P = 0.898) and disease-free survival (59.9% without mucin vs 56.9% with mucin, P = 0.813) did not differ between the groups.

CONCLUSION

The presence of mucin in rectal cancer with mucinous differentiation after preoperative CRT and resection is associated with male gender and a good tumour response grade, without significant impact on oncological outcome.

Clinical implications of mucinous components correlated with microsatellite instability in patients with colorectal cancer

AIM

Colorectal cancer (CRC) with microsatellite instability (MSI) is characterized by frequent poor differentiation or mucinous histology. The purpose of this study was to evaluate the association of MSI with clinicopathological features and the oncological outcome in patients with a mucinous component.

METHOD

CRC tissue samples were analysed for histology and MSI. Patients were grouped according to the mucinous content of the tumour, as follows: > 50%, mucinous adenocarcinoma (MA); ≤ 50%, adenocarcinoma with mucinous component (AMC); none, nonmucinous adenocarcinoma (NMA). Clinicopathological parameters and survival were compared between patient groups.

RESULTS

Of 2025 patients, 84 (4%) had MA and 124 (6%) had AMC. In addition, 202 (10%) had MSI. Patients with MA and AMC tended to have a younger age of onset, right-colon predilection, large-sized tumour and high frequency of MSI compared with those with NMA (P < 0.001). MA and AMC patients with MSI showed a trend towards right-colon predilection and infrequent lymph-node metastasis compared with those with microsatellite stability (MSS; P = 0.005-0.03). There were no survival differences between the three groups, but patients with MSI-MA demonstrated lower 4-year recurrence and better overall survival rates than those with MSS-MA (P = 0.018 and P = 0.046, respectively).

CONCLUSION

Clinicopathological features of AMC and MA were similar and closely associated with MSI status. Although the prognoses of AMC and MA were no different from that of NMA, survival of patients with an MSI-MA tumour was significantly better than for those with MSS-MA tumours.

Psychiatric morbidity in Chinese patients with chronic hepatitis B infection in a local infectious disease clinic

OBJECTIVE. To determine the prevalence of psychiatric morbidity, identify correlates of psychiatric morbidities, and evaluate the effectiveness of the 12-item General Health Questionnaire as a screening tool for psychiatric morbidity in Chinese patients infected with chronic hepatitis B. METHODS. This cross-sectional study was conducted in a local public specialist outpatient infectious disease clinic from October 2008 to June 2009, in which a total of 160 patients were randomly selected. Psychiatric diagnoses were established by using the Chinese-Bilingual Structured Clinical Interview for the DSM-IV (Axis I Disorders). Scores for the General Health Questionnaire were compared against the psychiatric diagnoses. RESULTS. Among 149 patients, the respective point prevalence of overall psychiatric disorders, depressive disorders, and anxiety disorders was 32%, 16%, and 14%. A family history of psychiatric disorder and absence of knowledge of mode of hepatitis B virus transmission were identified as being associated with current psychiatric disorders, current depressive disorders, and current anxiety disorders. Absence of a confidant was an independent factor for current depressive disorders and use of herbal medicine in the previous month was an independent factor for current anxiety disorders. CONCLUSIONS. Psychiatric disorders are common in Chinese patients with chronic hepatitis B. Identifying associated factors and using the General Health Questionnaire as a screening tool are useful for identifying patients with psychiatric disorders in an infectious disease clinic.

Citosol (thiamylal sodium) triggers apoptosis and affects gene expressions of murine leukemia RAW 264.7 cells

Citosol (thiamylal sodium) is one of generally used anesthetic–sedative agents for clinical patients, and it has not been reported to show induction of cytotoxic effects in cancer cells, especially in mice leukemia RAW 264.7 cells in vitro. In the present study, we investigated the cytotoxic effects of citosol on mice leukemic RAW 264.7 cells, including the effects on protein and gene expression levels which are determined by Western blotting and DNA microarray methods, respectively. Results indicated that citosol induced cell morphological changes, cytotoxic effect, and induction of apoptosis in RAW 264.7 cells. Western blotting analysis demonstrated that citosol promoted the levels of Fas, cytochrome c, caspase 9 and 3 active form and Bax levels, but it suppressed Bcl-xl protein level that may lead to apoptotic death in RAW 264.7 cells. Furthermore, DNA microarray assay indicated that citosol significantly promoted the expression of 5 genes (Gm4884, Gm10883, Lce1c, Lrg1, and LOC100045878) and significantly inhibited the expression of 24 genes (Gm10679, Zfp617, LOC621831, Gm5929, Snord116, Gm3994, LOC380994, Gm5592, LOC380994, LOC280487, Gm4638, Tex24, A530064D06Rik, BC094916, EG668725, Gm189, Hist2h3c2, Gm8020, Snord115, Gm3079, Olfr198, Tdh, Snord115, and Olfr1249). Based on these observations, citosol induced cell apoptosis and influenced gene expression in mice leukemia RAW 264.7 cells in vitro.

Validation of the seventh edition of the American Joint Committee on Cancer tumor-node-metastasis (AJCC TNM) staging in patients with stage II and stage III colorectal carcinoma: analysis of 2511 cases from a medical centre in Korea

AIM

The sixth and seventh editions of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) system for patients with stage II and stage III colorectal carcinoma (AJCC-6 and AJCC-7) were compared.

METHOD

Between 2000 and 2007, 2511 stage II/III colorectal carcinoma patients received primary surgical resection at the Asan Medical Center (Seoul, Korea). All patients were staged using AJCC-6 and AJCC-7 TNM systems. Patients with synchronous or other cancers, those given preoperative chemotherapy or radiotherapy and those in whom fewer than 12 lymph nodes were resected, were excluded. Overall survival (OS) and disease-free survival (DFS) were compared.

RESULTS

Of 2511 patients, 255 (10.2%) had different stages in the AJCC-6 and AJCC-7. For the AJCC-7, the 5-year OS by stage was 94.2% for stage IIA, 88.8% for stage IIB, 83.5% for stage IIC, 91.8% for stage IIIA, 81.8% for stage IIIB and 72.0% for stage IIIC. The OS and the DFS were not significantly different for the new substages IIB (n = 57) and IIC (n = 34) (P = 0.34 and P = 0.87, respectively). For the 187 patients with stage T3N2a cancer, the OS and the DFS were significantly different from stage IIIB other than T3N2a (P = 0.008 and P = 0.01, respectively) and there were no statistically significant differences in OS between the T3N2a group and the IIIC group (P = 0.46).

CONCLUSION

The study indicates that AJCC-7 has better prognostic validity than AJCC-6 for staging of patients with stage II and stage III colorectal carcinoma.

Safrole induces apoptosis in human oral cancer HSC-3 cells

Phytochemicals have been used as potential chemopreventive or chemotherapeutic agents. However, there are data suggesting a mutagenic effect of some phytochemicals. We hypothesized that safrole would have anticancer effects on human oral squamous cell carcinoma HSC-3 cells. Safrole decreased the percentage of viable HSC-3 cells via induction of apoptosis by an increased level of cytosolic Ca(2+) and a reduction in the mitochondrial membrane potential (ΔΨ(m)). Changes in the membrane potential were associated with changes in the Bax, release of cytochrome c from mitochondria, and activation of downstream caspases-9 and -3, resulting in apoptotic cell death. In vivo studies also showed that safrole reduced the size and volume of an HSC-3 solid tumor on a xenograft athymic nu/nu mouse model. Western blotting and flow cytometric analysis studies confirmed that safrole-mediated apoptotic cell death of HSC-3 cells is regulated by cytosolic Ca(2+) and by mitochondria- and Fas-dependent pathways.

A dual-design expandable colorectal stent for malignant colorectal obstruction: results of a multicenter study

BACKGROUND AND STUDY AIMS

It is known that metal stent placement is safe, easy, and effective for the treatment of malignant colorectal obstruction, but these stents are associated with delayed complications of tumor ingrowth and stent migration. The aim of this study was to prospectively investigate the technical feasibility, clinical effectiveness, and safety of a dual-design colorectal stent (consisting of an outer stent and an inner bare nitinol stent) in patients with malignant colorectal obstruction.

PATIENTS AND METHODS

Placement of the dual stent using a 4.5-mm stent delivery system was attempted in 151 patients with malignant colorectal obstruction, either before surgery (n = 50) or for palliation (n = 101). Multivariate logistic regression analysis was used to identify risk factors associated with complications.

RESULTS

Stent placement was technically successful in 145/151 patients (96%). Of the patients who had a technically successful placement, bowel obstruction resolved within 2 days after stent placement in 48/50 (96%) of the patients in the bridge-to-surgery group and in 87/95 (92%) of the patients in the palliative group. Perforation occurred in 16 patients, incomplete stent expansion in eight patients, stent migration in four patients, tumor overgrowth in five patients, severe rectal pain in five patients, and bleeding in eight patients. Complete obstruction was the only significant risk factor for perforation (odds ratio 6.88, 95% CI 2.04-23.17, P = 0.002). In the palliative group, the median survival was 152.0 days and the mean survival was 263.8 days.

CONCLUSIONS

The dual stent with a 4.5-mm stent delivery system is easy to insert, safe, and reasonably effective for the palliative treatment of malignant colorectal obstruction. However, a great deal of care is needed in its deployment because of the high rate of perforation.

Low-grade fibromyxoid sarcoma of the colon

Low-grade fibromyxoid sarcoma is a recently recognised soft tissue neoplasm. It is rare and has a tendency to arise from deep soft tissue of the lower extremities. An origin from the colon has not been reported in the medical literature. We report the low-grade fibromyxoid sarcoma originating from the colon in a 43-year-old male patient, treated by right hemicolectomy and nephrectomy.

The prevalence and risk factors of post-inflammatory hyperpigmentation after fractional resurfacing in Asians

BACKGROUND

Ablative laser resurfacing is considered to be the main therapeutic option for the treatment of wrinkles and acne scarring. However, in Asians, post-inflammatory hyperpigmentation (PIH) is a common adverse effect of laser resurfacing. Fractional resurfacing is a new concept of skin rejuvenation whereby zones of micro thermal injury are generated in the skin with the use of a 1,540-nm laser. The risk and prevalence of hyperpigmentation in dark-skinned patients using this approach have not been studied.

OBJECTIVE

To assess the prevalence and risk factors of PIH that is associated with the use of fractional resurfacing in Asians.

METHOD

A retrospective study of 37 Chinese patients who were treated with fractional resurfacing for acne scarring, skin rejuvenation, and pigmentation was carried out. In all of the cases, pre- and post-treatment clinical photographs (from standardized and cross-polarized views) were taken using the Canfield CR system. Two independent observers assessed the photographs. A prospective study of treatments of nine different density and energy levels that were applied to the forearms of 18 volunteers was also performed. Clinical photographs were assessed pre- and post-treatment for evidence of PIH.

RESULT

In the retrospective study, 119 treatment sessions were performed. Sixty-eight treatment sessions were high energy, low density; 51 sessions were low energy, high density. Patients who underwent a high energy but low-density treatment (range of energy 7-20 mJ; average energy 16.3 mJ, 1,000 MTZ) were associated with a lower prevalence of generalized PIH (7.1% vs. 12.4%) than those who underwent a low energy but high-density (range of energy 6-12 mJ; average energy 8.2 mJ, 2,000 MTZ) treatment. However, the difference was not statistically significant. Localized PIH occurred in the peri-oral area among patients who did not receive air cooling as an adjunctive therapy.

CONCLUSION

Both the density and energy of the treatment determines the risk of PIH in dark-skinned patients. Density may be of more important but further studies are necessary to determine this. Cooling to prevent bulk tissue heating is also important, especially in small anatomical areas. By using adequate parameters, the risk of PIH in dark-skinned patients can be significantly reduced.

Observation of two new N* peaks in J/psi-->ppi-n and ppi+n decays

The decay J/psi-->NNpi provides an effective isospin 1/2 filter for the piN system due to isospin conservation. Using 58x10(6) J/psi decays collected with the Beijing Electromagnetic Spectrometer at the Beijing Electron Positron Collider, more than 100 thousand J/psi-->ppi-n+c.c. events are obtained. Besides the two well-known N* peaks at around 1500 MeV/c2 and 1670 MeV/c2, there are two new, clear N* peaks in the ppi invariant mass spectrum around 1360 MeV/c2 and 2030 MeV/c2 with statistical significance of 11sigma and 13sigma, respectively. We identify these as the first direct observation of the N*(1440) peak and a long-sought missing N* peak above 2 GeV/c2 in the piN invariant mass spectrum.

Efficacy of PET/CT in the accurate evaluation of primary colorectal carcinoma

AIM

This study was performed to assess in the accurate evaluation of primary colorectal carcinoma using PET/CT.

METHODS

One hundred patients with primary colorectal carcinoma were evaluated during 2004. All patients underwent PET/CT when their preoperative serum carcinoembryonic antigen was >or=10 ng/mL or when CT showed equivocal findings. The appropriateness of PET/CT-induced changes was noted by subsequent operative findings and follow-up.

RESULTS

PET/CT more detected 15 intra-abdominal metastatic lesions than abdomino-pelvic CT scan. PET/CT showed true negative findings in 13 patients and false positive or negative findings in 10. Due to PET/CT results, management plans were altered in 27 patients; 9 had inter-modality changes, 10 received more extensive surgery, and 8 avoided unnecessary procedures.

CONCLUSIONS

PET/CT altered management plan in 24% of patients with primary colorectal carcinoma in correct direction. These findings suggest that PET/CT should be considered a part of standard work up for preoperative evaluation in a subset of patients with colorectal carcinoma.

Analysis of colonoscopic findings in the differential diagnosis between intestinal tuberculosis and Crohn's disease

BACKGROUND AND STUDY AIMS

Intestinal tuberculosis and Crohn's disease are chronic inflammatory bowel disorders that are difficult to differentiate from one another. This study aimed to evaluate the diagnostic value of various colonoscopic findings in the differential diagnosis between intestinal tuberculosis and Crohn's disease.

PATIENTS AND METHODS

Colonoscopic findings on initial work-up were prospectively recorded in patients with an initial diagnosis of either intestinal tuberculosis or Crohn's disease. These findings were analyzed after a final diagnosis of intestinal tuberculosis (n = 44) or Crohn's disease (n = 44) had been made after follow-up.

RESULTS

Four parameters (anorectal lesions, longitudinal ulcers, aphthous ulcers, and cobblestone appearance) were significantly more common in patients with Crohn's disease than in patients with intestinal tuberculosis. Four other parameters (involvement of fewer than four segments, a patulous ileocecal valve, transverse ulcers, and scars or pseudopolyps) were observed more frequently in patients with intestinal tuberculosis than in patients with Crohn's disease. We hypothesized that a diagnosis of Crohn's disease could be made when the number of parameters characteristic of Crohn's disease was higher than the number of parameters characteristic of intestinal tuberculosis, and vice versa. Making these assumptions, we calculated that the diagnosis of either intestinal tuberculosis or Crohn's disease would have been made made correctly in 77 of our 88 patients (87.5 %), incorrectly in seven patients (8.0 %), and would not have been made in four patients (4.5 %).

CONCLUSIONS

A systematic analysis of colonoscopic findings is very useful in the differential diagnosis between intestinal tuberculosis and Crohn's disease.

Metachronous colorectal cancer

OBJECTIVE

Although the diagnosis of metachronous colorectal cancer have increased, due primarily to improvements in diagnostic modalities, the potential risk factors for these tumours are not well known. We compared the characteristics of patients with metachronous and sporadic primary colorectal cancer to determine risk factors for its occurrence.

PATIENTS AND METHODS

We reviewed the records of 5447 patients with colorectal cancer, who had been treated at Asan Medical Centre between July 1989 and January 2004. A metachronous cancer was defined as a secondary colorectal cancer occurring more than 6 months after the index cancer.

RESULTS

Metachronous colorectal cancer occurred in 39 (0.7%) patients. Their average age was 53 years, somewhat younger than the average age of sporadic colorectal cancer patients (58 years). In patients with metachronous cancer, the cancer was more likely to be located in the right colon (P < 0.03), and the incidence of synchronous polyps or cancer was significantly higher (P < 0.001). The relative distributions of histological grades and clinicopathological characteristics were similar in index and metachronous cancers. Metachronous cancers were diagnosed more frequently at an early stage. The time interval between index and metachronous cancer ranged from 6 to 215 months (mean 39 months), with 13 (33.3%) patients diagnosed with metachronous cancer after 5 years.

CONCLUSION

We found that in patients aged < 50 years, existence of synchronous polyps or cancer influence on the development of metachronous colorectal cancer. Regular follow-up is necessary for early detection, even after 5 years, for these patients.

Diffusion tensor imaging in the assessment of normal-appearing brain tissue damage in relapsing neuromyelitis optica

BACKGROUND AND PURPOSE

Normal-appearing brain tissue (NABT) damage was established in multiple sclerosis by histology, MR spectroscopy, magnetization transfer imaging and diffusion tensor imaging (DTI). However, whether this phenomenon can be detected in relapsing neuromyelitis optica (RNMO) remains unclear. The aim of this study was to use DTI to investigate the presence of NABT damage in RNMO patients and its possible mechanism.

METHODS

Conventional MR imaging and DTI scans were performed in 16 patients with RNMO without visible lesions on brain MR imaging and in 16 sex- and age-matched healthy control subjects. Histogram analysis of mean diffusivity (MD) and fractional anisotropy (FA) was performed in the entire brain tissue (BT), white matter (WM), and gray matter (GM). Region of interest (ROI) analysis of MD and FA was also performed in WM regions connected with the spinal white matter tracts or optic nerve (including medulla oblongata, cerebral peduncle, internal capsule, and optic radiation), in corpus callosum without direct connection with them, and in some GM regions.

RESULTS

From histogram analysis, we found the RNMO group had a higher average MD of the BT, WM, and GM, a lower average MD peak height and a higher average MD peak location of the GM, and a higher average FA peak height of the WM than did the control group. From ROI analysis, compared with control subjects, RNMO patients had a higher average MD and a lower average FA in ROIs of WM connected with the spinal white matter tracts or optic nerve and a normal average MD and FA in corpus callosum without direct connection with them. In addition, a high average MD was found in parietal GM in these patients.

CONCLUSIONS

Our findings confirm the presence of abnormal diffusion in brain tissue in patients with RNMO and suggest that secondary degeneration caused by lesions in the spinal cord and optic nerve might be an important mechanism for this abnormality.

Preclinical application of radioimmunoguided surgery using anti-carcinoembryonic antigen biparatopic antibody in the colon cancer

Radioimmunoguided surgery (RIGS) has been known as a sophisticated tool to detect micrometastasis intraoperatively. A preclinical model of RIGS was designed to test the possible clinical applicability of the biparatopic antibody in detecting colorectal cancer. The biparatopic antibody was constructed using two anti-carcinoembryonic antigen (CEA)-specific antibodies, T84.66 and PR1A3, reacting against two different epitopes. (125)I-labeled biparatopic antibody was introduced via the principal colonic arteries at the end of operation in 10 operable patients with colon cancer. After 24 h, the radioactivities of the tumors and lymph nodes were counted using the gamma-detecting probe. The radioactivity count was performed ex vivo. The accurate detection in the primary tumors and metastatic lymph nodes were 100 and 88.7% respectively. False-positive detections occurred in 24 of 256 lymph nodes (9.4%), whereas false-negative detections occurred in 5 of them (2%). The most frequent cause of false-positive detection was dissociated radionuclides trapped in the lymphatic tissues. False-negative detections occurred mainly from weak targeting by radiolabeled antibody, probably due to weak expression of tumor CEA. Conclusively, as most detection errors appear to be reduced within 3 days in vivo, the biparatopic antibody can efficiently be applied to the clinical RIGS, thereby facilitating accurate detection and removal of occult cancer foci in colorectal cancer.

Singlet oxygen luminescence as an in vivo photodynamic therapy dose metric: validation in normal mouse skin with topical amino-levulinic acid

Although singlet oxygen (¹O₂) has long been proposed as the primary reactive oxygen species in photodynamic therapy (PDT), it has only recently been possible to detect it in biological systems by its luminescence at 1270 nm. Having previously demonstrated this in vitro and in vivo, we showed that cell survival was strongly correlated to the ¹O₂ luminescence in cell suspensions over a wide range of treatment parameters. Here, we extend this to test the hypothesis that the photobiological response in vivo is also correlated with ¹O₂ generation, independent of individual treatment parameters. The normal skin of SKH1-HR hairless mice was sensitised with 20% amino-levulinic acid-induced protoporophyrin IX and exposed to 5, 11, 22 or 50 J cm⁻² of pulsed 523 nm light at 50 mW cm⁻², or to 50 J cm⁻² at 15 or 150 mW cm⁻². ¹O₂ luminescence was measured during treatment and the photodynamic response of the skin was scored daily for 2 weeks after treatment. As observed by other authors, a strong irradiance dependence of the PDT effect was observed. However, in all cases the responses increased with the ¹O₂ luminescence, independent of the irradiance, demonstrating for the first time in vivo an unequivocal mechanistic link between ¹O₂ generation and photobiological response.

Diallyl disulfide (DADS) induced apoptosis undergo caspase-3 activity in human bladder cancer T24 cells

Diallyl disulfide (DADS), one of the major components of garlic (Allium sativum), is well known to have chemopreventative activity against human cancer such as colon, lung and skin. But the exact mechanism of the action is still unclear. In this study, we investigated how DADS--induced cell cycle arrest and apoptosis in T24 human bladder cancer cells in vitro. Apoptosis induction, cell viability, cell cycle arrest, caspases-3, -9 activity and gene expression were measured to determine their variation by flow cytometric assay, western blot, and determination of caspase-3 activity, PCR and cDNA microarray. There are significant differences in cell death (decreased viable cells then increased the amounts of apoptosis) of T24 cells that were detected between DADS (5-75 microM) treated and untreated groups. A significant increase was found in apoptosis induction when cells were treated with DADS (50 microM) compared to without DADS treated groups. DADS also promoted caspase-3 activity after exposure for 1, 3, 6, 12, and 24 h, which led to induce apoptosis. DADS also increased the product of intracellular hydrogen peroxide. Furthermore, the DADS-induced apoptosis on T24 cells was blocked by the broad-spectrum caspase inhibitor, z-VAD-fmk and antioxidant (catalase). DADS also increased cyclin E and decreased CDK2 gene expression which may lead to the G2/M arrest of T24 cells.

Observation of a threshold enhancement in the plambda invariant-mass spectrum

An enhancement near the m(p)+M(Lambda) mass threshold is observed in the combined pLambda and pLambda invariant-mass spectrum from J/psi-->pK(-)Lambda;+c.c. decays. It can be fit with an S-wave Breit-Wigner resonance with a mass m=2075+/-12(stat)+/-5(syst) MeV and a width of Gamma=90+/-35(stat)+/-9(syst) MeV; it can also be fit with a P-wave Breit-Wigner resonance. Evidence for a similar enhancement is also observed in psi(')-->pK(-)Lambda;+c.c. decays. The analysis is based on samples of 5.8x10(7)J/psi and 1.4x10(7)psi(') decays accumulated in the BES II detector at the Beijing Electron-Positron Collider.

The clinicopathological significance of inferior mesenteric lymph node metastasis in colorectal cancer

AIMS

There are few studies reporting survival or recurrence patterns in colorectal cancer patients with inferior mesenteric lymph node metastasis (IMLN+). The present study evaluated the prognostic significance of patients being IMLN+ or IMLN- in colorectal cancer.

METHODS

Survival, recurrence pattern and treatment protocols were compared between 63 IMLN+ patients and 108 IMLN- patients with stage III and IV rectal and sigmoid cancer undergoing curative surgery. Lymph node sampling was routinely performed prior to inferior mesenteric artery ligation and excision flush with aorta. Limited principal node dissection including IMLN was performed in cases of identified node metastasis.

RESULTS

The 5-year disease-free survival rates were 50% in IMLN- and 31% in IMLN+ patients (P=0.004). The 5-year disease-free survival rate was greater in the N1 group than the N2 group (P=0.038). Cox regression analysis showed IMLN+, lymphovascular tumour invasion, T4, M1, and pre-operative serum CEA level over 6 ng/ml were independently associated with unfavorable disease-free survival. The prognostic significance of M category was greater when the IMLN+ was included in the M1 as opposed to the N category. In patients undergoing absolute curative surgery, post-operative recurrence rates were 34% for IMLN- and 57% for IMLN+ patients (P=0.009; OR, 2.611; 95% CI, 1.313-5.194). For IMLN+ patients, post-operative adjuvant treatment independently correlated with disease-free survival (P=0.029).

CONCLUSIONS

IMLN+ is an independent survival factor enhancing the prognostic significance of the M category in the AJCC staging. Curative radical surgery and post-operative chemoradiotherapy appears to be warranted for IMLN+ colorectal cancer patients as it resulted in 5-year disease-free survival rates of up to 31% compared to 50% in IMLN- patients.

Observation of the decay psi(2S)-->K0SK0L

The decay psi(2S)-->K(0)(S)K(0)(L) is observed using psi(2S) data collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider; the branching fraction is determined to be B(psi(2S)-->K(0)(S)K(0)(L))=(5.24+/-0.47+/-0.48)x10(-5). Compared with J/psi-->K(0)(S)K(0)(L), the psi(2S) branching fraction is enhanced relative to the prediction of the perturbative QCD "12%" rule. The result, together with the branching fractions of psi(2S) decays to other pseudoscalar meson pairs (pi(+)pi(-) and K+K-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.

Observation of a near-threshold enhancement in the pp mass spectrum from radiative J/psi-->gammapp decays

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

hMLH1 and hMSH2 mutations in families with familial clustering of gastric cancer and hereditary non-polyposis colorectal cancer

The pattern of hMLHI and hMSH2 mutations was assessed to identify the genetic correlation between hereditary gastric and colorectal cancers. Four disease groups and their healthy family members were assembled according to the presentation of gastric cancer: FG, familial clustering of gastric cancer (n = 32); CG, family with one or more colorectal and gastric cancers in first-degree relatives (n = 22); HS, seven HNPCC families corresponding to the Amsterdam criteria (AMS+) and 12 suspected HNPCC families which did not satisfy one of the criteria (AMS-), but no gastric cancer among first- and second-degree relatives (n = 19); and SG, sporadic gastric cancer (n = 33). In the CG group, three were included in AMS + and six in AMS- criteria. Peripheral blood was obtained from them to detect hMLHI and hMLH2 mutations using PCR-SSCP analysis and direct sequencing. The incidence of mutations was 9.4% in the FG group, 54.5% in the CG group, 31.6% in the HS group, and none in the SG group. The incidence, type, and number of the mutation were not different between the CG and HS groups. Thirty-four different mutations included 19 in hMLH1 and 15 in hMSH2. Gastric cancer was the most common extracolonic malignancy in HNPCC and suspected HNPCC families (9/28, 32.1%). The hMLH1 or hMSH2 mutation occurred in seven of 10 families with AMS+, whereas it occurred in four of 18 with AMS- (70% vs. 22.2%, P = .013). Five mutations in the hMLH1 and six mutations in the hMSH2 were exclusively found in families with gastric cancer. All three mutations in the FG group were in hMLHI and there was no mutation in their healthy family members. This study demonstrates that some familial clustering type of gastric cancer appears to be associated with hMLHI mutations thereby indicating a difference from the hereditary gastric cancer studies previously reported. In addition, hMLHI and hMSH2 mutations may impact the gastric cancer carcinogenesis in HNPCC or suspected HNPCC.

Development and inter-rater reliability of a standardized verbal instruction manual for the Chinese Geriatric Depression Scale-short form

The Geriatric Depression Scale (GDS) is a common screening tool for elderly depression in Hong Kong. This study aimed at (1) developing a standardized manual for the verbal administration and scoring of the GDS-SF, and (2) comparing the inter-rater reliability between the standardized and non-standardized verbal administration of GDS-SF. Two studies were reported. In Study 1, the process of developing the manual was described. In Study 2, we compared the inter-rater reliabilities of GDS-SF scores using the standardized verbal instructions and the traditional non-standardized administration. Results of Study 2 indicated that the standardized procedure in verbal administration and scoring improved the inter-rater reliabilities of GDS-SF.

Measurements of the cross section for e(+)e(-) --> hadrons at center-of-mass energies from 2 to 5 GeV

We report values of R = sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->mu(+)mu(-)) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.

Source of errors in the evaluation of early rectal cancer by endoluminal ultrasonography

PURPOSE

Although preoperative evaluation of early rectal cancers can be done by endoluminal sonography and by means of colonoscopic findings, it is still controversial whether endoluminal sonography can effectively discriminate mucosal from submucosal lesions. This study was performed to verify objective causes of errors in the evaluation of early rectal cancer (T0/1) using a review of videotaped endoluminal sonography images.

METHODS

Eighty-nine patients with suspected early rectal cancer on endoluminal sonography were included. Two different scanners with appropriate probes were used according to tumor location, i.e., transrectal ultrasonography was used to scan up to 8 cm of the rectum above the anal verge, whereas endoscopic ultrasonography was used to assess higher lesions. Endoluminal sonography images were correlated with histologic infiltration and were reevaluated carefully to identify sources of errors.

RESULTS

Sensitivity and specificity were 83.1 and 96.5 percent, respectively, for tumor staging, whereas sensitivity was very low compared with specificity (16.7 vs. 90.2 percent) for metastatic lymph nodes. Endoluminal sonography images showed irregularity of the underlying tumor border (P < 0.01) and hypoechoic blurring or cutoff of the inner and outer hypoechoic layers (P < 0.001), all of which closely correlated with histologic infiltration of tumor cells. Overstaging occurred more than twice as often as understaging in tumor reevaluation (14 vs. 5 occurrences). In contrast to tumors, lymph nodes showed a similar amount of both overstaging (four cases) and understaging (five cases). The sources of errors were summarized as five types: false instrumentation, interpretive errors, anatomic defects, imaging failure, and inevitable errors.

CONCLUSIONS

Because false instrumentation, interpretive errors, and anatomic defects were considered preventable, 23 (82.1 percent) of the 28 errors might have been avoided. Therefore, a clear image by endoluminal sonography can effectively distinguish mucosal from submucosal lesions in early rectal cancer.

Mutations at the APC exon 15 in the colorectal neoplastic tissues of serial array

Although the APC protein is known to participate in cellular proliferation and apoptosis, APC mutations have been thought to play a major role in the early stage of colorectal tumorigenesis. The somatic APC mutation of exon 15 was assessed to determine its impact on various stages of colorectal tumorigenesis. The colorectal neoplastic tissues of serial array studied included sporadic adenomas (group 1, n = 36), adenomas (group 2, n = 33), and carcinomas (group 3, n = 32) in the synchronous adenoma and carcinoma as well as sporadic carcinomas (group 4, n = 36). Aberrant DNA was detected by protein truncation test and confirmed by direct sequencing. The mutation prevalence was 36.1% in group 1, 45.5% in group 2, 59.4% in group 3, and 41.7% in group 4 with no differences among the groups. Among the 18 patients with synchronous adenoma and carcinoma, 9 had mutation in their adenomas and 12 in their carcinomas. The mutation loci and patterns did not differ in adenomas and carcinomas. Mutations in the mutation cluster region (MCR) were much more frequent than in the preceding region of MCR, i.e., 85.7% vs. 14.3%. The mutation prevalence of villous adenomas appeared greater than that of tubular adenoma (3/21 vs. 3/4). Predominant pathogenic mutations at MCR suggest that the APC mutation is implicated in all stages of colorectal tumorigenesis.

Combination of oxaliplatin, fluorouracil, and leucovorin in the treatment of fluoropyrimidine-pretreated patients with metastatic colorectal cancer

There has been no standard therapy for patients with metastatic colorectal cancer who have failed to first-line fluorouracil-based treatment. The present study was designed to assess the efficacy and toxicities of a combination of oxaliplatin, 5-fluorouracil (5-FU) and leucovorin in fluoropyrimidine-pretreated patients with metastatic colorectal cancer. Chemotherapy consisted of oxaliplatin 85 mg/m2 on day 1, followed by leucovorin 20 mg/m2 and 5-FU 1,200 mg/m2 on days 1 and 2. Treatment courses were repeated every two weeks. Thirty-nine patients were enrolled in this study. All patients previously received fluoropyrimidine-based chemotherapy. Thirty-one patients were assessable for response and 33 for treatment toxicity. Six patients required dose reduction of 5-FU due to grade III/IV cytopenia. Nausea/vomiting and peripheral neuropathy were common non-hematologic toxicities. Overall response rate was 42.0% including 3 complete response and 10 partial response. The median response duration was 91 days (range, 28-224+). The median duration of progression-free survival was 132 days (range, 40-308). A combination of oxaliplatin, 5-FU, and leucovorin showed high response rate in fluoropyrimidine-pretreated patients with metastatic colorectal cancer, but the duration of response was relatively short. It may be worthwhile to explore its therapeutic potential in the first-line treatment setting.

Hybrid LMS-MMSE inverse halftoning technique

The objective of this work is to reconstruct high quality gray-level images from bilevel halftone images. We develop optimal inverse halftoning methods for several commonly used halftone techniques, which include dispersed-dot ordered dither, clustered-dot ordered dither, and error diffusion. At first, the least-mean-square (LMS) adaptive filtering algorithm is applied in the training of inverse halftone filters. The resultant optimal mask shapes are significantly different for various halftone techniques, and these mask shapes are also quite different from the square shape that was frequently used in the literature. In the next step, we further reduce the computational complexity by using lookup tables designed by the minimum mean square error (MMSE) method. The optimal masks obtained from the LMS method are used as the default filter masks. Finally, we propose the hybrid LMS-MMSE inverse halftone algorithm. It normally uses the MMSE table lookup method for its fast speed. When an empty cell is referred, the LMS method is used to reconstruct the gray-level value. Consequently, the hybrid method has the advantages of both excellent reconstructed quality and fast speed. In the experiments, the error diffusion yields the best reconstruction quality among all three halftone techniques.

Ileal pouch-anal anastomosis in patients with indeterminate colitis: long-term results

PURPOSE

Patients with chronic ulcerative colitis who undergo proctocolectomy and are found intraoperatively to harbor histologic signs suggesting Crohn's disease have indeterminate colitis; nonetheless, ileal pouch-anal anastomosis is usually performed. The aim of this study was to determine the long-term outcome of ileal pouch-anal anastomosis in patients with indeterminate colitis compared with a cohort of patients with chronic ulcerative colitis.

METHOD

Review of an ileal pouch-anal anastomosis registry identified 1,437 patients with chronic ulcerative colitis and 82 patients with indeterminate colitis who underwent an ileal pouch-anal anastomosis between 1981 and 1995. The median follow-up was 83 (range, 1-192) months. Demographic data and functional outcomes were compared by chi-squared and Wilcoxon's rank-sum tests. Probabilities of complications and pouch failure were analyzed using Kaplan-Meier and log-rank techniques. Finally, Bonferroni adjustments were used for multiple comparisons.

RESULTS

Patients with indeterminate colitis and chronic ulcerative colitis were comparable in terms of gender and length of follow-up. The mean age of the chronic ulcerative colitis group was higher (34 vs. 31; P < 0.01). At ten years patients with indeterminate colitis had significantly more episodes of pelvic sepsis (17 percent indeterminate colitis vs. 7 percent chronic ulcerative colitis; P < 0.001), pouch fistula (31 vs. 9 percent; P < 0.001), and pouch failure (27 vs. 11 percent; P < 0.001). Importantly, during follow-up fully 15 percent of patients with indeterminate colitis, but only 2 percent of patients with chronic ulcerative colitis, had their original diagnosis changed to Crohn's disease (P < 0.001). When the outcomes of these patients newly diagnosed with Crohn's disease were considered separately, the rate of complications for the remaining patients with indeterminate colitis was identical to that of patients with chronic ulcerative colitis. Functional outcomes were comparable among all three groups.

CONCLUSION

After ileal pouch-anal anastomosis patients with indeterminate colitis who did not develop Crohn's disease subsequently experienced long-term outcomes nearly identical to patients with chronic ulcerative colitis. Crohn's disease, whether it develops after surgery for chronic ulcerative colitis or indeterminate colitis, is associated with poor long-term outcomes.

Applicability of carcinoembryonic antigen-specific monoclonal antibodies to radioimmunoguided surgery for human colorectal carcinoma

Two carcinoembryonic antigen (CEA)-specific monoclonal antibodies (MAbs), PR1A3 and T84.66, were tested to determine whether they could accurately localize colorectal carcinoma and therefore be applicable in radioimmunoguided surgery (RIGS). Twenty-one tumors by three human colorectal carcinoma cell lines with various levels of CEA expression (KM-12c, C75, and Clone A) were successfully implanted in the intra-abdominal organs of 15 nude mice. The tumors was localized using a portable radioisotope detector (Neoprobe 1000) 48 h after injection of radiolabeled MAbs (10 mCi/mouse) when the precordial counts were <20 per 2 s. Histopathological identification of radiolabeled MAbs were also performed using immunohistochemistry and microautoradiography. Radioactivity counted on a portable radioisotope detector correlated well with that on a gamma counter. The distribution in the blood was significantly greater than in other organs (P < 0.001). Localization indices of the tumor in various organs was from 1.1 to 8.5 in the PR1A3-pretreated mice and 3.0 to 8.6 in the T84.66-pretreated mice. Silver grains and immune staining were distributed in the tumor cells of the PR1A3-pretreated mice, whereas they were in the necrotic debris as well as the tumor cells of the T84.66-pretreated mice. There were significantly more silver grains in the liver in the T84.66-pretreated mice than in the PR1A3-pretreated mice (P = 0.004). The sensitivity and specificity of tumor localization by RIGS were 71.4 and 91.4% in the PR1A3-pretreated mice, whereas they were 60 and 76% in the T84.66-pretreated mice. A study using specific anti-CEA MAbs suggested PR1A3 as an efficient immune probe for RIGS in colorectal carcinoma with a low rate of false-positive detection.

Efficiency of combined colonoscopy and computed tomography for diagnosis of colonic actinomycosis: a retrospective evaluation of eight consecutive patients

The preoperative diagnosis of colonic actinomycosis is accurate in fewer than 20% of patients. Colonoscopy and computed tomography (CT) findings were analyzed to ascertain their diagnostic value and their role in determining therapeutic modality and outcome. Before and after treatment we retrospectively evaluated eight consecutive patients with colonic actinomycosis, all of whom were women with a previous history of intrauterine contraceptive device use. Median follow-up period was 20 months (7-57). Localized nodules were found in all cases by colonoscopy; half of these nodules included umbilication at the apex. The colonic mucosa demonstrated normal to moderate inflammation as well as hyperemia and edema. Mucosal ulceration was found in only one case. All cases showed some degree of stenosis. These findings differ from those in other inflammatory or neoplastic diseases of the colon. Abdominopelvic CT revealed extramural involvement of heterogeneous lesions all cases. Contrast enhancement also indicated severe thickening of the colonic wall (7-20 mm) with focal and dense enhancement in six cases. Seven of eight patients required surgery for diagnostic or therapeutic purposes. Complete resolution was determined using both colonoscopy and CT. As more than half of these cases could have been safely managed using an adequate antibiotic treatment, diagnostic studies indicating a high likelihood of colonic actinomycosis should be evaluated to avoid unnecessary surgeries carried out for diagnostic purposes. A combination of colonoscopy and CT appears to be important for both diagnosis and management because of their compensatory findings of mucosal and extramucosal lesions, respectively.

Isolated splenic metastasis from colorectal carcinoma: a case report

Isolated splenic metastasis arising from colorectal carcinoma is very rare and there has been only 6 cases reported in the English literature. A new case is presented, and its possible pathogenesis was considered with previously reported cases. A 65-year-old male patient had received a right hemicolectomy for ascending colon cancer 36 months earlier. He was followed up regularly with serial measurement of serum carcinoembryonic antigen (CEA). Rising serum CEA was discovered from 33 months postoperatively and CT revealed an isolated splenic metastasis. He therefore underwent splenectomy, which was proven to be a metastatic adenocarcinoma with similar histological feature to the original tumor. As all reported cases showed elevated serum CEA at the time of metastasis, isolated splenic metastasis might be associated with CEA in regard to its biological functions of immunosuppression and adhesion.

CT features of metastatic linitis plastica to the rectum in patients with peritoneal carcinomatosis

OBJECTIVE

We examined the CT features of 22 patients with metastatic linitis plastica to the rectum.

CONCLUSION

Metastatic linitis plastica to the rectum should be considered when CT shows a long segment of circumferential rectal wall thickening, especially in patients with peritoneal carcinomatosis from gastric cancer. In such patients, CT helps avoid unnecessary extensive surgery.

Influence of PLIF cage size on lumbar spine stability

STUDY DESIGN

In vitro biomechanical testing on functional spine units with posterior lumbar interbody fusion cage implants of progressively larger sizes.

OBJECTIVES

To determine the influence of increasing cage size on the restoration of spine stability after total facetectomy.

SUMMARY OF BACKGROUND DATA

Bilateral insertion of cages in posterior lumbar interbody fusion commonly involves facetectomy. To restore stability with no additional instrumentation, the cages must provide sufficient distraction of the vertebrae and adequate tension in the anulus. The size of cages is therefore an important consideration in posterior lumbar interbody fusion.

METHODS

Eight human lumbar functional spine units were obtained and divided into two equal groups; one group underwent bending tests and the other twisting. The functional spinal units were tested intact, after total bilateral facetectomy and with three sets of cages that were progressively larger in size.

RESULTS

After facetectomy, the functional spine unit's stiffness reduced significantly from that of the intact spine in extension (48% of intact), lateral bending (25%), and torsion (39%). With the posterior insertion of small cages into the facetectomized functional spine units, only extension stiffness was restored to the intact level, whereas flexion stiffness reduced significantly (41% of intact). The medium cages restored the lateral bending stiffness of the facetectomized functional spine units; only the large cages managed to restore the torsional stiffness. Flexion stiffness of the facetectomized functional spine units with cages remained significantly less than that of the intact spine, regardless of cage size.

CONCLUSION

In the facetectomized lumbar spine unit, cage size influences lateral bending and torsional stability.

Somatic mutations of the first 14 exons of APC in hamartomatous polyps of the colon

Although hamartomatous or hyperplastic polyps are rarely accompanied by adenomatous or carcinomatous foci, the role of APC (MIM# 175100) mutations in these polyps is not clear. The neoplastic potential of these polyps was assessed with regard to somatic mutation of the first 14 exons of APC. DNA from 14 hamartomatous polyps (12 patients with juvenile polyp, JP; two patients with Peutz-Jeghers syndrome, PJS) and 27 hyperplastic polyps was used. Exons 1-14 of APC were amplified using verified oligonucleotide primers, and PCR-SSCP analysis was performed. Translation-terminating mutation in exon 15 was also screened using the protein truncation test. All mutations found were transitions or transversions with heterozygous alleles of both wild-type and mutant APC in exons 2, 9, 10, and 11. Four hamartomatous polyps (three from JP and one from PJS) showed seven, new mutations and one common APC variant (codon 486), whereas no hyperplastic polyps demonstrated mutation. APC mutation was not correlated with previous history of colorectal carcinoma or number of polyps. Since all mutations were missense or silent mutations occurred in exons not previously known to have functionally relevant area, their phenotypic implication appeared to be limited.

Usefulness of CT in patients with intestinal obstruction who have undergone abdominal surgery for malignancy

OBJECTIVE

The purpose of this study was to evaluate the usefulness of CT in determining the causes of intestinal obstruction in patients who have undergone abdominal surgery for malignancy.

MATERIALS AND METHODS

We analyzed the CT scans of 55 patients with benign (n = 26) or malignant (n = 29) intestinal obstruction that developed after abdominal surgery for malignancy. After calculating the diagnostic accuracy of interpretations by three radiologists, we compared CT findings for benign and malignant intestinal obstructions with respect to peritoneal involvement patterns and other ancillary findings. Multivariate logistic regression analysis was used to determine the diagnostic performance of CT in revealing causes of obstruction.

RESULTS

Diagnostic accuracies of the three radiologists were 67%, 75%, and 78%. CT findings indicating malignant obstruction were a mass at the site of obstruction or prior surgery, lymphadenopathy, or an abrupt transition zone and irregular bowel wall thickening at obstructed sites (p < .05). Conversely, the chance for benign obstruction increased when CT revealed mesenteric vascular changes, a large amount of ascites, or a smooth transition zone and smooth bowel wall thickening at the obstructed site (p < .05). With multivariate logistic regression analysis using two variables (a mass at the site of obstruction or prior surgery and lymphadenopathy), we calculated the overall accuracy of CT as 84% (46/55 patients).

CONCLUSION

CT is useful in differentiating benign from malignant intestinal obstructions in patients who have undergone abdominal surgery for malignancy. However, CT has limitations in patients not having a demonstrable peritoneal mass.

Familial juvenile polyposis coli with APC gene mutation

Familial juvenile polyposis has been known to have malignant potential, but their genetic relation to familial adenomatous polyposis has not been proven yet. Two young brothers with intermittent rectal bleeding revealed multiple juvenile polyposis. Their father had a history of rectal cancer with multiple colonic polyps. Four frequent exons of APC gene mutation were tested from these patients' white blood cells by polyacrylamide gel electrophoresis and sequencing. The 21-yr-old brother had a missense mutation (GAA-->GGA) at codon 1309, whereas the 18-yr-old brother showed a missense mutation (ATA-->GTA) at codon 1304 in exon 15 of APC gene. Three of four first-degree relatives were affected with familial juvenile polyposis, familial juvenile polyposis with adenomatous change, and rectal cancer with multiple polyps. The APC gene mutation of familial juvenile polyposis in this case suggests a genetic relationship with familial adenomatous polyposis.

Spine surgery in geriatric patients

AIM

Many elderly patients are crippled by degenerative spine conditions. Operative treatment is often not offered due to fear of complications and consideration of life span. The objective of this study was to look at the diagnosis, surgical results and post-operative complications of elderly patients who underwent spinal surgery.

METHODS

A cohort of 44 patients, 65 years and older, who had surgery in Tan Tock Seng Hospital from January 1990-August 1995 were reviewed. Twenty-five of them had spinal stenosis, II had tumour and 9 had traumatic fracture/dislocation/subluxation. There were 3 patients each with disc herniation, infection and spondylolisthesis. Nine patients had more than one diagnosis. All patients were investigated post-operatively. The data was entered into a computer-coded protocol. The diagnosis was determined intraoperatively. Type of surgery, co-morbid conditions and results were looked into. Patient's opinion on relief symptoms was graded on a 5-point scale. Functional improvement was tabulated as the patient's ambulatory status.

RESULTS

The analysis of results was divided into two groups, patients with tumour and those without tumour. Twenty-seven of the 33 patients without tumour were alive at follow-up. Twenty-six of these patients had improvement of symptoms and 18 of 27 had improved functional status post-operatively. In the group with tumours, 2 had worsening symptoms and 3 had decreased function.

CONCLUSION

Surgical intervention should be a treatment option in elderly patients with spinal disease.

Results of minor foot amputations in diabetic mellitus

The aim of this retrospective study is to study the outcome of surgery in diabetic patients with foot infections. The results of 54 local amputations performed by surgeons of different levels of experience for gangrene and/or deep infection confined to the toes in diabetic patients were studied. Failure of surgery is defined as any case that requires subsequent surgery. Twenty-two of the initial local amputations subsequently required higher amputations. The majority of these cases that failed were done by junior officers of Medical Officer and Registrar grade. In contrast, the cases done by senior surgeons are more likely to heal. Fifty-six percent of the initial operations done by Medical Officers failed. A similar pattern is also seen in repeat operations done by junior officers. Based on our findings, it is recommended that the decision making must be made by senior staff of at least Registrar grade. Repeat surgery should also be done by senior staff. Finally, continued training and supervision of junior staff are necessary to improve their technical expertise, judgment and knowledge.

Perioperative nutrition and postoperative complications in patients undergoing spinal surgery

STUDY DESIGN

The authors undertook a three-part study to better understand the impact of perioperative nutritional status on postoperative complications in patients undergoing spinal surgery. In preliminary Parts I and II, the authors targeted two groups of patients who are particularly nutritionally challenged. In Part III, they studied a large group of consecutive patients undergoing routine lumbar spinal fusion.

OBJECTIVES

To determine whether preoperative nutritional status was a significant predictor of postoperative complications in patients undergoing elective lumbar spinal fusion.

SUMMARY OF BACKGROUND DATA

In Part I, 27 patients treated surgically for vertebral osteomyelitis were divided into two groups based on their preoperative nutritional status. Twenty-four of the 26 postoperative complications were in the malnourished group (P < 0.001). In Part II, 15 (75%) of 20 patients treated surgically for spinal cord injury were found to become malnourished in the postoperative period. Seventeen complications were noted, all in the malnourished group (P = 0.001).

METHODS

One hundred fourteen consecutive patients undergoing selective lumbar decompression and fusion were identified and their records reviewed. In addition to preoperative nutritional status, data gathered included age, sex, height, weight, past medical history, steroid use, alcohol use, tobacco use, type of bone graft (allograft vs. autograft), history of previous lumbar surgery, number of levels fused, and use of spinal instrumentation.

RESULTS

Eleven of 13 postoperative infectious complications (10 deep wound infections) were noted in the malnourished group (P < 0.001). By stepwise logistic regression analysis, preoperative nutritional status was an extremely significant independent predictor of postoperative complications in patients undergoing elective lumbar spinal fusion (P = 0.0018).

CONCLUSIONS

The prevalence data in our study population suggest that a large number (25%) of patients undergoing elective lumbar spine surgery are nourished inadequately at surgery. This number is higher (42%) in older patients. The authors recommend that close attention be paid to the perioperative nutritional status of patients undergoing lumbar spinal surgery. Patients with suboptimal nutritional parameters should be supplemented and replenished before elective surgery.

Wide versus selective decompression in the operative treatment of lumbar spinal stenosis

The early post-operative results of wide versus selective decompression in a group of 64 patients with lumbar spinal stenosis were studied with the aim of ascertaining whether a more limited approach gives comparable results to the more traditional method of wide decompression. Wide decompression involved complete removal of a vertebral lamina at the stenotic level. Selective decompression refers to removal of the lower part of the superior lamina and the upper part of the inferior lamina at the stenotic level together with limited facetectomies. Patients were compared with respect to post-operative relief of back pain and sciatica/claudication as well as the ability to return to their pre-morbid level of functional activity. Follow up ranged from 4 months to 26 months. Results showed that both wide and selective decompression were able to achieve complete or considerable relief of symptoms and return to pre-morbid level of activity in 74% to 84% of patients. The results in the 2 groups were not statistically different. It appears that within the first 2 years of surgery, the vast majority of our post-decompression patients had good results regardless of whether wide or selective decompression was used.