Boehmite nanostructures preparation by hydrothermal method from anodic aluminium oxide membrane

Boehmite nanostructures were successfully synthesized from porous anodic aluminium oxide (AAO) membrane by a simple and efficient hydro-thermal method. The experiment used high purity alumina as raw material, and the whole reaction process avoided superfluous impurities to be introduced. Thus, the purity of Boehmite products was ensured. The examinations of the morphology and structure were carried out by atomic force microscope (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Composition of the specimens was analyzed using energy dispersive X-ray spectroscope (EDX) and X-ray diffraction (XRD). Based on these observations the growth process was analyzed.

Photorefractive dynamic properties of Ca2+-doped strontium barium niobate crystals

Measurements for photorefractive dynamic properties under polarized light with different luminous intensity and wavelength at 650 nm were performed in calcium-doped strontium barium niobate crystals as a function of the time. Experimental results further validated that the different input luminous intensities influence only the saturated time and photorefractive velocity of the photorefractive crystals. Birefringence experiments suggest that an input luminous intensity oscillatory threshold should exist between 64 mW/cm(2) and 13 mW/cm(2). The dynamic change of refractive index from self-focusing to asymmetric self-defocusing was also measured and regarded as the mutual results of the nonuniform-intensity incidence and positive thermal lens effect, which was validated by a further experiment based on the Michelson interference. Also, oscillation accompanying change in the dynamic indices was analyzed and attributed to the high dielectric effect as well as asymmetric self-defocusing in this investigation.

Subpicosecond pulse generation from a Nd:CLNGG disordered crystal laser

We report on a diode-pumped passively mode-locked subpicosecond Nd:CLNGG disordered crystal laser for the first time to our knowledge. Owing to the large inhomogeneous broadening and spectrum splitting of the disordered crystal, the Nd:CLNGG laser generated 900 fs mode-locked pulses with a repetition rate of approximately 88 MHz at 1061 nm wavelength. With a single-emitter laser diode pumping, a maximum average output power of 486 mW was achieved with a slope efficiency of 26%. Our experimental results show that the four-level Nd:CLNGG disordered crystal could be an excellent alternative for subpicosecond pulse generation.

Genomic sequencing and characterization of a Chinese isolate of Bovine viral diarrhea virus 2

The complete genomic sequencing and characterization of Bovine viral diarrhea virus (BVDV) isolate XJ-04 originated from cattle in China was described. The genomic RNA of the isolate was 12,284 nt long and contained short 5'- untranslated region (UTR), 3'-non-coding regions (NCR), and one open reading frame (ORF) encoding a large polyprotein of 3,895 amino acids with 20 potential N-glycosylation sites. The identity of the isolate XJ-04 with reference strains NADL (BVDV-1) and 890 (BVDV-2) in autoprotease (N(pro)) gene and structural genes (C, E(rns), E1, E2) was analyzed. The percentage of nt and aa identity in analyzed genes indicated that the isolate XJ-04 was closer to the reference strain 890 (BVDV-2) than to NADL (BVDV-1). Phylogenetic analysis revealed that the isolate belonged to BVDV-2a subtype. Furthermore, comparison analysis indicated that the isolate XJ-04 did not contain any genomic insertions that can be directly related to the cytopathic phenotype.

Massive lower gastrointestinal bleeding from an external iliac artery fistula in a patient with bladder cancer

Arterioenteric fistula is a rare cause of lower gastrointestinal bleeding, yet it can potentially cause massive, life-threatening bleeding. Patients with an advanced pelvic malignancy can develop hemorrhage from an arterioenteric fistula. Selective mesenteric angiography is unable to demonstrate the source of bleeding in these patients, so evaluation of the iliac arteries is essential. We present a 67-year-old man with advanced bladder cancer presenting as massive, life-threatening lower gastrointestinal bleeding from an external iliac arterial fistula to the cecum.

Prevalence and genotype identification of human JC virus in colon cancer in Taiwan

Although JC virus (JCV), a human polyomavirus, has been detected in colon cancers, the association between JCV and colon cancer remains controversial. In Taiwan, the prevalence of JCV infection in colon cancer patients has not been reported. Thus, the purpose of this study was to investigate JCV infection in colon cancers in Taiwan. Formalin-fixed, paraffin-embedded tissues from 22 colon cancer patients were examined in this study. Nested PCR was performed to detect viral genomic DNA. The product of the nested PCR flanking the JCV regulatory region was sequenced further. Viral large tumor protein, LT, and late capsid protein, VP1, were examined by immunohistochemistry (IHC). Nested PCR revealed JCV genomic DNA in 86.4% (19/22) of the colon cancer tissue samples. Both rearranged and archetypal genotypes of JCV were identified. Expression of JCV LT was positive in 63.6% (14/22) of the examined colon cancer tissue samples but not in any adjacent normal region. Expression of viral capsid protein VP1 was not detected in any of the tissues examined. The current study demonstrates that JCV genomic DNA was present in the examined colon cancer tissues. The genotypes of JCV in colon cancer tissues were also identified. Expression of viral early protein but not structural capsid protein was detected in the examined colon cancer tissues. Furthermore, a high prevalence of JCV infection in colon cancer tissues in Taiwan was also demonstrated.

Dual-wavelength synchronously mode-locked Nd:CNGG laser

We have experimentally demonstrated a dual-wavelength synchronously mode-locked Nd:CNGG laser based on the semiconductor saturable absorber mirror technique. Mode locking was achieved simultaneously on two gain bands of the crystal that have a central wavelength separation of 2.4 nm. The fundamental mode-locked pulse train has a repetition rate of 88 MHz and pulse duration of 5 ps, with an average output power of approximately 90 mW. Autocorrelation measurements show that each of the synchronously mode-locked pulses consists of a train of quasi-periodic beat pulses with a 660 fs pulse width and a 0.63 THz repetition rate.

Oxidative stress in Chinese patients with Leber's hereditary optic neuropathy

The cellular mechanisms of Leber's hereditary optic neuropathy (LHON) are poorly understood and there is little information on the onset of blindness and neurological degeneration. Here we define the relationship between oxidative stress and LHON pathogenicity at the cellular level. Venous blood was obtained from 14 patients with LHON, 21 asymptomatic maternal relatives and 30 normal individuals (controls). The level of free radicals in blood was assessed as luminol luminescence immediately and at 10 min after addition of phytohaemagglutinin. In LHON patients and their asymptomatic relatives, free radicals increased significantly immediately after adding phytohaemagglutinin compared with baseline and normal controls. After 10 min, however, there were no significant differences between and within the groups. These results suggest that the antioxidant capacity is reduced in the blood of patients with LHON and in asymptomatic relatives, and that oxidative stress plays a significant role in the pathogenesis of LHON.

Superoxide destabilization of beta-catenin augments apoptosis of high-glucose-stressed mesangial cells

Intense mesangial cell apoptosis contributes to the pathogenesis of diabetic nephropathy. Although reactive oxygen radicals and Wnt signaling components are potent regulators that modulate renal tissue remodeling and morphogenesis, cross-talk between oxidative stress and Wnt/beta-catenin signaling in controlling high-glucose-impaired mesangial cell survival and renal function have not been tested. In this study, high glucose induced Ras and Rac1 activation, superoxide burst, and Wnt5a/beta-catenin destabilization and subsequently promoted caspase-3 and poly (ADP-ribose) polymerase cleavage and apoptosis in mesangial cell cultures. The pharmacological and genetic suppression of superoxide synthesis by superoxide dismutase and diphenyloniodium, dominant-negative Ras (S17N), and dominant-negative Rac1 (T17N) abrogated high-glucose-induced glycogen synthase kinase (GSK-3beta) activation and caspase-3 and poly (ADP-ribose) polymerase degradation. Inactivation of Ras and Racl also reversed Wnt/beta-catenin expression and survival of mesangial cells. Stabilization of beta-catenin by the transfection of stable beta-catenin (Delta45) and kinase-inactive GSK-3beta attenuated high-glucose-mediated mesangial cell apoptosis. Exogenous superoxide dismutase administration attenuated urinary protein secretion in diabetic rats and abrogated diabetes-mediated reactive oxygen radical synthesis in renal glomeruli. Immunohistological observation revealed that superoxide dismutase treatment abrogated diabetes-induced caspase-3 cleavage and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) and increased Wnt5a/beta-catenin expression in renal glomeruli. Taken together, high glucose induced oxidative stress and apoptosis in mesangial cells. The Ras and Rac1 regulation of superoxide appeared to raise apoptotic activity by activating GSK-3beta and inhibiting Wnt5a/beta-catenin signaling. Controlling oxidative stress and Wnt/beta-catenin signaling has potential for protecting renal tissue against the deleterious effect of high glucose.

Tailoring the ultrathin Al-induced crystallization temperature of amorphous si by application of interface thermodynamics

It has been demonstrated theoretically and experimentally that the thickness of a very thin, pure Al film put on top of an amorphous Si (a-Si) layer can be used as a very accurate tool to control the crystallization temperature of a-Si. The effect has been explained quantitatively by application of surface-interface thermodynamics. The predictions have been confirmed experimentally by a real-time in situ spectroscopic ellipsometry investigation of the crystallization temperature of a-Si as a function of the thickness of ultrathin Al layers.

Fabrication of high-aspect-ratio Fresnel zone plates by e-beam lithography and electroplating

The fabrication of gold Fresnel zone plates, by a combination of e-beam lithography and electrodeposition, with a 30 nm outermost zone width and a 450 nm-thick structure is described. The e-beam lithography process was implemented with a careful evaluation of applied dosage, tests of different bake-out temperatures and durations for the photoresist, and the use of a developer without methylisobutylketone. Electrodeposition with a pulsed current mode and with a specially designed apparatus produced the desired high-aspect-ratio nanostructures. The fabricated zone plates were examined by electron microscopy and their performances were assessed using a transmission X-ray microscope. The results specifically demonstrated an image resolution of 40 nm.

Efficient operation of a diode-pumped Yb:NaY(WO(4))(2) laser

An efficient diode-pumped Yb:NaY(WO(4))(2) (Yb:NYW) disordered crystal laser has been experimentally demonstrated for the fist time. The Yb:NYW crystal has a peak absorption cross section of 1.09 x 10(-20) cm(2) at 972 nm and emission cross section of 1.24 x 10(-20) cm(2) at 1010 nm. Under an absorbed pump power of 11.7 W, the Yb:NYW laser generated an average output power as high as 4.1 W, with a slope efficiency of 45%. It was found that the laser always operated in a self-pulsing mode, and the laser spectrum showed random jumps with time. The mechanism of self-pulsing in the laser was also investigated.

Mismatch repair protein expression in Amsterdam II criteria-positive patients in Taiwan

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is characterized genetically by germline mutations in DNA mismatch repair (MMR) genes. Immunohistochemistry (IHC) has high sensitivity and specificity for identifying MMR-deficient tumours. This study investigated the clinical presentations and frequency of HNPCC in Taiwan by combined Amsterdam II criteria (AC-II) and IHC.

METHODS

In 1995-2003, 7108 patients with primary colorectal cancer registered in Chang Gung Memorial Hospital's Colorectal Cancer Registry were screened using AC-II. Tumour specimens were analysed for MMR protein expression by IHC, and relevant clinicopathological details were documented.

RESULTS

Some 83 patients fulfilled the AC-II. Clinicopathologically, 43 patients (52 per cent) had proximal tumours, ten (12 per cent) had poorly differentiated cancers, 17 (20 per cent) had mucinous adenocarcinoma and 51 (61 per cent) had stage I-II tumours. Seventeen patients developed second primary colonic and extracolonic cancers over a mean 7.2-year follow-up. Immunohistochemically, 58 patients were MMR protein deficient. They had a significantly earlier age of onset (P < 0.001), more proximal tumour location (P = 0.002), less advanced tumour stage (P = 0.008) and more second primary cancers (P = 0.017) compared with MMR-competent patients.

CONCLUSION

These data show significant differences in clinical features between MMR protein-deficient and MMR competent subgroups.

Malignant mixed müllerian tumor of primary mesenteric origin associated with a synchronous ovarian cancer: case report and literature review

Malignant mixed müllerian tumor (MMMT) is a rare tumor in females and extragenital MMMT is even more so. We report a patient with MMMT primarily in the mesentery with synchronous ovarian cancer. In the English literature, 42 cases of extragenital MMMT have been reported other than the presented case, and this is only the second MMMT arising from the mesentery. Furthermore, among the cases reviewed, MMMTs tend to be associated with synchronous or metachronous colonic cancer or gynecologic tumors originating from the müllerian duct, including ovarian tumors, fallopian tube cancer, endometrial cancer, cervical cancer, and serous carcinoma of the peritoneum (14 out of 43 patients; 32.6%). The risk factors for MMMT include obesity, nulliparity, exogenous estrogen, and long-term tamoxifen use. The prognosis of MMMT is catastrophic and the treatment is based on the experience of those of uterine sarcomas, which is composed of operation, radiotherapy and chemotherapy.

Digestion of frozen/thawed food waste in the hybrid anaerobic solid-liquid system

The hybrid anaerobic solid-liquid (HASL) system, which is a modified two-phase anaerobic digester, is to be used in an industrial scale operation to minimize disposal of food waste at incineration plants in Singapore. The aim of the present research was to evaluate freezing/thawing of food waste as a pre-treatment for its anaerobic digestion in the HASL system. The hydrolytic and fermentation processes in the acidogenic reactor were enhanced when food waste was frozen for 24h at -20 degrees C and then thawed for 12h at 25 degrees C (experiment) in comparison with fresh food waste (control). The highest dissolved COD concentrations in the leachate from the acidogenic reactors were 16.9 g/l on day 3 in the control and 18.9 g/l on day 1 in the experiment. The highest VFA concentrations in the leachate from the acidogenic reactors were 11.7 g/l on day 3 in the control and 17.0 g/l on day 1 in the experiment. The same volume of methane was produced during 12 days in the control and 7 days in the experiment. It gave the opportunity to diminish operational time of batch process by 42%. The effect of freezing/thawing of food waste as pre-treatment for its anaerobic digestion in the HASL system was comparable with that of thermal pre-treatment of food waste at 150 degrees C for 1h. However, estimation of energy required either to heat the suspended food waste to 150 degrees C or to freeze the same quantity of food waste to -20 degrees C showed that freezing pre-treatment consumes about 3 times less energy than thermal pre-treatment.

Enhancement of food waste digestion in the hybrid anaerobic solid-liquid system

The hybrid anaerobic solid-liquid (HASL) system is a modified two-phase anaerobic digester for food waste treatment. To enhance the performance of anaerobic digestion in the HASL system, thermal pre-treatment (heating at 150 degrees C for 1 h) and freezing/thawing (freezing for 24 h at-20 degrees C and then thawing for 12 h at 25 degrees C) were proposed for food waste pre-treatment before the anaerobic digestion. Both processes were able to alter the characteristics and structure of food waste favoring substance solubilization, and hence production of methane. However, there was no net energy gain when the energy required by the pre-treatment processes was taken into account.

Simvastatin reverses high glucose-induced apoptosis of mesangial cells via modulation of Wnt signaling pathway

BACKGROUND/AIMS

Disruption of Wnt/beta-catenin signaling in mesangial cells is a pathogenic consequence of diabetic nephropathy. We examined the role of simvastatin (SIM) in modulation of Wnt/beta-catenin signaling in the apoptosis of high glucose (HG)-stressed mesangial cells in vitro and in vivo.

METHODS

For in vitro studies, we cultured mesangial cells, with or without SIM pretreatment, in 35 mM glucose and then assayed Wnt activity and apoptosis. For in vivo studies, we administered SIM to streptozocin-induced diabetic rats for 28 days and then dissected renal tissues for immunohistological assessment of Wnt signal expression and apoptosis of glomerular cells.

RESULTS

SIM reduced the promotional effect of HG on caspase-3 expression, PARP activation, and cell apoptosis. HG significantly reduced Wnt4 and Wnt5a mRNA expression and SIM restored Wnt4 and Wnt5a mRNA expression to the level of controls. SIM also suppressed HG-mediated activation of GSK-3b and restored nuclear beta-catenin levels and phospho-Akt expression. This suggests that SIM alters the stability of beta-catenin, a critical element of mesangial cell survival. Exogenous SIM treatment blocked DNA fragmentation, increased the Wnt/beta-catenin immunoreactivities of cells adjacent to renal glomeruli, and attenuated urinary protein secretion in diabetic rats.

CONCLUSIONS

SIM reduces the detrimental effects of HG on diabetic renal glomeruli in vitro and in vivo. SIM prevents HG-induced downregulation of Wnt/beta-catenin signaling and thereby blocks mesangial cell apoptosis.

Methylglyoxal-induced fibronectin gene expression through Ras-mediated NADPH oxidase activation in renal mesangial cells

BACKGROUND

The formation of methylglyoxal (MGO), a highly reactive dicarbonyl compound, is accelerated under diabetic conditions. Although recent studies have suggested that apoptotic cell death is involved in diabetic nephropathy, the precise mechanism of MGO-induced renal fibrosis remains to be elucidated.

METHODS

Rat kidney mesangial cells with or without pretreatment with inhibitors, including superoxide dismutase, catalase, L-NAME, diphenylene iodonium, rotenone, allopurinol, PD98059, SB203580 and SP600125 were cultured in medium containing 100 microM MGO. In the MGO-treated cell culture system, fibrosis-related signalling pathway was assessed by enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction and western blotting.

RESULTS

Expression of fibronectin induced by MGO was highest after 48 h treatment. Superoxide production rapidly increased after 2 h and remained at a high level for 24 h. Scavenging O(2) (-) reversed transforming growth factor beta 1 (TGF-beta1) and fibronectin mRNA level. Pretreatment with diphenylene iodonium significantly suppressed MGO-induced superoxide, TGF-beta1 expression and fibronectin gene expression, indicating that NADPH oxidase is responsible for inducing superoxide formation and subsequently induced renal fibrosis. High MGO rapidly enhanced Ras activation in 1 h and progressively increased cytosolic p38 activation. Additionally, SB203580 pretreatment reduced MGO promotion of fibronectin gene activation suggesting that cytosolic p38 activation might affect MGO-induced renal mesangial fibrosis. Inhibiting Ras activity with manumycin A significantly reduced the promoting effect of MGO on superoxide synthesis, and fibronectin expression.

CONCLUSION

Induction of superxoide by Ras via p38 pathway activates fibrotic gene transcription of mesangial cells. Reduction of oxidative stress by scavenging superoxide may offer an alternative strategy for controlling MGO-induced renal fibrosis.

Metastatic Merkel cell carcinoma in the rectum: report of a case

Merkel cell carcinoma is a rare, aggressive skin malignancy of neuroendocrine origin with predominant occurrence in the elderly males. Approximately 50 percent of patients with Merkel cell carcinoma develop distant metastasis at some point during the disease course; hence, Merkel cell carcinoma always has a poor prognosis. Distant metastasis has never been disclosed in the rectum to the best of our knowledge. We present a 76-year-old male with clinical manifestation of massive hematochezia and final diagnosis of metastatic Merkel cell carcinoma in the rectum. We conclude that radical resection of rectal metastatic Merkel cell carcinoma is important in the management strategy of a patient with recurrence and lymph node metastases.

Stapled hemorrhoidopexy for prolapsed hemorrhoids in patients with liver cirrhosis; a preliminary outcome for 8-case experience

PURPOSE

To investigate the efficacy and safety of stapled hemorrhoidopexy in treating prolapsed hemorrhoids in patients with liver cirrhosis.

PATIENTS AND METHODS

Eight consecutive cases of patients with prolapsed hemorrhoids comorbid with liver cirrhosis, who had intractable response to other interventions, were enrolled in this retrospective study between January 2002 and June 2006 at our institute. Six patients (75%) had Child-Pugh class A liver cirrhosis, whereas only two patients (25%) had class B disease. Rectal varices were identified in three patients (37.5%), and esophageal varices were identified in six patients (75%). Concurrent rectal and esophageal varices existed in three patients (37.5%). The patients underwent stapled hemorrhoidopexy with Proximate PPH-03 in a lithotomy position under spinal/intravenous general anesthesia.

RESULTS

There was no procedure-related mortality or major complications except hemorrhage. Two patients (25%) were complicated with postoperative staple-line bleeding, which was managed with conservative treatment without reoperation. There were no leading symptoms of relapsing during a follow-up period of at least 6 months.

CONCLUSIONS

This study may prove that stapled hemorrhoidopexy is a feasible and safe approach for prolapsed hemorrhoids concurrent with liver cirrhosis.

Regional cerebral blood flow between primary and concomitant fibromyalgia patients: a possible way to differentiate concomitant fibromyalgia from the primary disease

OBJECTIVES

Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) has been used to detect abnormal regional cerebral blood flow (rCBF) in women with primary fibromyalgia (FM). The main aim of this study was to investigate the rCBF deficit in concomitant FM patients and compare it with primary FM.

METHODS

An observational study was designed to analyse the SPECT findings in 92 female patients recruited from January 2002 to January 2004. Differences in the rCBF hypoperfusive areas between 49 primary and 29 concomitant FM patients were assessed in different areas of the brain using the chi(2)-test for statistical significance.

RESULTS

Tc-99m ECD brain SPECT in 71 FM patients revealed heterogeneous rCBF in comparison to the homogeneous scan in 14 control patients. The most prominent rCBF hypoperfusive region in both primary and concomitant FM groups was the left temporoparietal area, followed by the thalamus, right temporoparietal, frontal, and basal ganglia areas. Differences in rCBF hypoperfusion in these areas for both FM groups were not significant (all p>0.5).

CONCLUSIONS

Reduced rCBF at cortical regions, in addition to previously reported areas at the thalamus and the subcortical nucleus, in FM patients was demonstrated in this study. The perfusion deficit areas were similar between primary and concomitant FM when the underlying disease activity was quiescent. The feasibility of using this neuroimaging study to differentiate FM from the primary disease, such as rheumatoid arthritis (RA)-associated depression and neuropsychiatric lupus, should be considered.

Randomized comparison between stapled hemorrhoidopexy and Ferguson hemorrhoidectomy for grade III hemorrhoids in Taiwan: a prospective study

PURPOSE

Short-term and mid-term outcomes of stapled hemorrhoidopexy (SH) were compared with those for Ferguson hemorrhoidectomy (FH) for treating hemorrhoids.

MATERIALS AND METHODS

Patients with prolapsed hemorrhoids were randomized into two groups treated with SH (N = 300) and FH (N = 296) at Chang Gung Memorial Hospital at Chiayi in Taiwan between January 2002 and December 2004. The outcomes of the procedures were evaluated postoperatively (short-term, i.e., intra-/postoperative conditions, hospital stay, pain intensity scoring, time off work, and procedure-related morbidity) and over a follow-up period of minimum 18 months (mid-term, i.e., relapse of prolapse and/or bleeding, anal stricture, anal sepsis, and the acceptability of the procedures to the patients).

RESULTS

SH was superior to FH in operative time, intraoperative blood loss, postoperative pain intensity, and return to work. Based on telephone interviews over the follow-up period, most patients who received SH appreciated the procedure better than those with FH.

CONCLUSIONS

This study confirms that SH generates less postoperative suffering, less time off work, and more complete resolution of primary symptoms associated with hemorrhoids in the mid-term follow-up than FH.

Iatrogenic femoral neuropathy following pelvic surgery: a rare and often overlooked complication--four case reports and literature review

Femoral neuropathy can result from diverse etiologies following abdominal surgery. We describe four cases of postoperative femoral neuropathy after proctological procedures that were carried out at our hospital. The related symptoms developed occultly but eventually impaired patient motor or sensory functions in the lower extremities. When the patient fails to address associated suffering, it is easy for clinicians to neglect this type of morbidity. All patients recovered from neuropathy following timely detection of the disease entity confirmed by electromyography and nerve conduction studies, followed by adequate rehabilitation management. We hypothesize that postoperative femoral neuropathy may be closely related to unsuitable applications of self-retaining retractors, rather than being associated with other factors, such as gender, age, surgery time or body mass index (BMI). Furthermore, we used a literature review to examine the pathophysiology, diagnoses and treatment modalities of femoral neuropathy resulting from inappropriate placement of self-retaining retractors. Based on a thorough comprehension of the femoral nerves anatomical course and meticulous placement of retractor blades, these types of iatrogenic complications may be prevented.

Epidermal growth factor regulates intestinal glutamine uptake during total parenteral nutrition

Sprague Dawley rats were randomised into three groups: group I (chow) were fed rat chow and water ad libitum, group II total parenteral nutrition (TPN) received a standard formula of TPN, and group III (TPN--epidermal growth factor (EGF)) received the same TPN as group II and injections of EGF (0.1 microg/gm body weight) subcutaneously twice daily. Glutamine (GLN) concentrations in tissues and blood were measured by reversed phase high performance liquid chromatography. Gut GLN extraction was calculated by dividing the difference in GLN concentrations (Conc) between the carotid artery (ART) and portal vein (PV) by the arterial concentration [(ART Conc - PV Conc)/ART Conc]. TPN induced a marked reduction of GLN concentration in tissues and blood, and also reduction of gut GLN extraction. When EGF was administered along with TPN, gut GLN concentration did not fall and gut GLN extraction was increased by 15% (TPN - EGF 1 week, P < 0.05). Arterial blood concentration of GLN was increased when TPN and EGF were used for 1 week (P < 0.05 vs control). But EGF did not prevent the GLN concentration of other tissues decreasing during TPN. Our results suggest that EGF can regulate intestinal uptake of GLN during TPN.

Biological effects of protons targeted to different ranges in Arabidopsis seeds

PURPOSE

To investigate the biological effects of radiation damage induced at different depths of a plant seed and to investigate the difference in radiation response between dry seeds and water-imbibed seeds to the same type of radiation.

MATERIALS AND METHODS

Arabidopsis seeds of the wild-type Columbia ecotype were used in our experiments. Dry or water-imbibed Arabidopsis seeds were irradiated with 1.1 MeV, 2.6 MeV or 6.5 MeV protons (H+). For comparison, 30 keV nitrogen ions (N+) were also used to irradiate dry Arabidopsis seeds. The germination and survival rates of the seeds were measured after each irradiation.

RESULTS

After irradiation with 2.6 MeV H+ and 6.5 MeV H+, the fluence-response curves for germination and survival had distinct shoulders and then survival was reduced rapidly with increasing fluence. 2.6 MeV H+ was more effective than 6.5 MeV H+ in inhibiting germination and survival and water-imbibed seeds were more sensitive to the 6.5 MeV H+ irradiation than dry seeds. For 1.1 MeV H+ the germination and survival rates were reduced gradually and an intermediate plateau emerged for germination, which was similar to that observed for survival following 30 keV N+ irradiation. One of the key morphologic malformations, the multi-SAM (shoot apical meristem), was observed both for dry and water-imbibed seeds after all proton irradiations and for the dry seeds after 30 keV N+ irradiation.

CONCLUSIONS

Radiation-induced damage produced at different ranges in Arabidopsis seeds results in different fluence-response curves with water-imbibed seeds being more sensitive to proton irradiation than dry seeds. As well as the shoot apical meristem (SAM) being the primary target for irradiation, there exists a secondary target around the SAM that also contributes to the radiation response.

Electron field emission characteristics and field evaporation of a single carbon nanotube

Direct transmission electron microscope (TEM) observations of the field emission and evaporation process of emitting carbon nanotubes (CNTs) shown that the tip structure of the CNT is in general composed of irregular shaped graphitic sheets which extend typically more than 10 nm from the end of the CNT. It is found that the irregular shaped graphitic sheets at the tip of the CNT may greatly enhance the field emission characteristics of the CNT when compared with that having an ideal circular edge. The field evaporation of the CNT proceeds typically via the removal of the irregular shaped graphitic sheets from the tip of the CNT, and field emission characteristics of a CNT depend far more sensitively on the tip structure than on the geometric length of the CNT.

A new iterative algorithm to reconstruct the refractive index

The latest developments in x-ray imaging are associated with techniques based on the phase contrast. However, the image reconstruction procedures demand significant improvements of the traditional methods, and/or new algorithms have to be introduced to take advantage of the high contrast and sensitivity of the new experimental techniques. In this letter, an improved iterative reconstruction algorithm based on the maximum likelihood expectation maximization technique is presented and discussed in order to reconstruct the distribution of the refractive index from data collected by an analyzer-based imaging setup. The technique considered probes the partial derivative of the refractive index with respect to an axis lying in the meridional plane and perpendicular to the propagation direction. Computer simulations confirm the reliability of the proposed algorithm. In addition, the comparison between an analytical reconstruction algorithm and the iterative method has been also discussed together with the convergent characteristic of this latter algorithm. Finally, we will show how the proposed algorithm may be applied to reconstruct the distribution of the refractive index of an epoxy cylinder containing small air bubbles of about 300 micro of diameter.

Prognostic significance of pre- and postoperative serum carcinoembryonic antigen levels in patients with colorectal cancer

BACKGROUND

To evaluate the prognostic significance of pre- and postoperative serum carcinoembryonic antigen(CEA) levels in colorectal cancer (CRC) patients.

METHODS

425 CRC patients underwent curative resection at our institution. Their pre- and postoperative serum CEA level was classified into two groups according to concentration: normal CEA (<5.0 ng/ml) and abnormal CEA (> or =5.0 ng/ml).

RESULTS

Of all patients, abnormal pre- and postoperative serum CEA levels were observed in 181 (42.6%) and 48 (11.3%) patients, respectively. Abnormal preoperative serum CEA level was significantly correlated with the tumor located in the colon, the depth of tumor invasion, the status of lymph node metastasis, UICC stage, and the presence of postoperative relapse (p < 0.05). Concurrently, an abnormal postoperative serum CEA level was also prominently related to the above corresponding parameters (p < 0.05), except for the tumor location. Patients with a failed conversion of abnormal preoperative value to normal postoperative concentration were found to have the worst overall survival rate. Abnormal pre- and postoperative serum CEA levels were single independent predictors for survival and postoperative relapse, respectively.

CONCLUSIONS

The identification of abnormal pre- and postoperative serum CEA levels may be useful in the auxiliary cancer prognosis or postoperative surveillance of CRC patients.

Passively Q-switched Yb3+:YCa4O(BO3)3 laser with InGaAs quantum wells as saturable absorbers

A diode-pumped Yb:YCOB laser at 1086 nm is passively Q switched by using InGaAs quantum wells as saturable absorbers and utilizing the Bragg mirror structure as an output coupler. With an absorbed pump power of 9.2 W the laser produces pulses of 100 ms duration with average pulse energy of as much as 165 microJ at a pulse repetition rate of 7 kHz.

The effect of smoking on tuberculosis: different patterns and poorer outcomes

SETTING

It has been well documented that smoking increases the risk of tuberculosis (TB). However, few studies have evaluated the impact of smoking on TB. We conducted this retrospective study to evaluate the influences of smoking on the manifestation and outcome of TB.

DESIGN

All culture-confirmed TB patients from July 2002 to December 2003 were identified and their medical records reviewed.

RESULTS

A total of 523 TB patients, including 207 (39.6%) who had ever smoked, were studied. The ever-smokers were significantly older, more likely to have underlying diseases and a duration of symptoms > 60 days, and less likely to have extra-pulmonary involvement and have completed treatment (64.7% vs. 78.5%). Radiographically, more ever-smokers with pulmonary tuberculosis (PTB) presented with miliary lesions, multiple nodules or masses, upper lung predominance and cavitation than never-smokers. Although smoking was associated with poor prognosis on univariate survival analysis, multivariate analysis revealed that independent poor prognostic factors included age, underlying disease, symptom duration < or = 60 days, extra-pulmonary involvement, serum albumin level < 3.5 g/dl and delayed treatment.

CONCLUSIONS

Our results demonstrate that smoking is significantly associated with radiographic manifestations of PTB, but not with death among PTB patients.

Roles of different subtypes of opioid receptors in mediating the ventrolateral orbital cortex opioid-induced inhibition of mirror-neuropathic pain in the rat

Previous studies have demonstrated that opioid receptors in the prefrontal ventrolateral orbital cortex (VLO) are involved in anti-nociception. The aim of this current study was to examine whether opioid receptors in the VLO have effects on the hypersensitivity induced by contralateral L5 and L6 spinal nerve ligation (SNL), termed as mirror neuropathic pain (MNP) in the male rat. Morphine (1.0, 2.5, 5.0 microg) microinjected into the VLO contralateral to the SNL depressed the mechanical paw withdrawal assessed by von Frey filaments and the cold plate (4 degrees C)-induced paw lifting in a dose-dependent manner on the side without SNL. These effects were antagonized by microinjection of the non-selective opioid receptor antagonist naloxone (1.0 mug) into the same VLO site. Microinjection of endomorphin-1 (5.0 microg), a highly selective mu-opioid receptor agonist, and [d-Ala(2), d-Leu(5)]-enkephalin (DADLE, 10 microg), a delta-/mu-receptor agonist, also depressed the MNP. The effects of both drugs were blocked by selective mu-receptor antagonist beta-funaltrexamine (beta-FNA, 3.75 microg), but the effect of the DADLE was not influenced by the selective delta-receptor antagonist naltrindole (5.0 microg). Microinjection of the kappa-opioid receptor agonist spiradoline mesylate salt (U-62066) (100 microg) had no effect on the MNP. These results suggest that the VLO is involved in opioid-induced inhibition of the MNP and the effect is mediated by mu- (but not delta- and kappa-) opioid receptors.

Mutations in BMPR-IB and BMP-15 genes are associated with litter size in Small Tailed Han sheep (Ovis aries)

The Small Tailed Han is a prolific local sheep breed in China. The bone morphogenetic protein receptor IB (BMPR-IB) gene, which affects the fecundity of Booroola Merino sheep, and the bone morphogenetic protein 15 (BMP-15) gene, which affects the fecundity of Inverdale, Hanna, Belclare, Cambridge, and Lacaune sheep, were studied as candidate genes associated with the prolificacy of Small Tailed Han sheep. Single nucleotide polymorphisms of BMPR-IB and BMP-15 genes were detected in Small Tailed Han ewes (n = 188) by PCR-RFLP. The combined effect of the 2 genes on the prolificacy of Small Tailed Han sheep was studied. The results indicated that the same FecB mutation (Q249R) occurred in the BMPR-IB gene in Small Tailed Han ewes as found in Booroola Merino ewes. The Small Tailed Han ewes with genotypes FecB(B)/FecB(B) and FecB(B)/FecB(+) had 1.40 (P < 0.01) and 1.11 (P < 0.01) more lambs, respectively, than those with genotype FecB(+)/FecB(+). The same FecX(G) mutation (Q239Ter) of the BMP-15 gene was found in Small Tailed Han ewes as in Belclare and Cambridge ewes. The Small Tailed Han ewes with the heterozygous mutant FecX(G)/FecX(+) had 0.55 (P < 0.01) more lambs than those with the wild-type FecX(+)/FecX(+). The Small Tailed Han ewes carrying mutations in both BMPR-IB and BMP-15 genes had greater litter size than those with either mutation alone. In view of our results, marker-assisted selection using both BMPR-IB and BMP-15 genes is warranted to increase litter size in sheep and will be of considerable economic value to sheep producers.

Synchronous prostate stromal sarcoma and gastrointestinal stromal tumor of rectum: case report and review of the literature

We report a case of prostate stromal sarcoma with initial presentation of obstructive voiding symptoms. The synchronous rectal gastrointestinal stromal tumor was also finally discovered. The patient underwent pelvic exenteration as the choice of treatment. Synchronous prostate stromal sarcoma and rectal gastrointestinal stromal tumor is an extremely rare disease in the literature view.

Association between expression of reproductive seasonality and alleles of melatonin receptor 1A in goats

To determine whether a link exists between reproductive seasonality and the structure of the melatonin receptor 1A (MTNR1A) gene, the latter was studied in year-round estrous breeds (Jining Grey and Boer goats) and seasonal estrous breeds (Liaoning Cashmere, Inner Mongolia Cashmere, Wendeng milk and Beijing native goats). A large fragment of exon 2 of MTNR1A gene was amplified by PCR using sheep sense and antisense primers in 260 does of six breeds. The uniform 824 bp PCR product was digested with restriction endonucleases MnII and RsaI, and checked for the presence of restriction sites. No polymorphism at the MnII cleavage sites was detected in all six goat breeds and no relationship could be established between the MnII cleavage sites of MTNR1A gene and reproductive seasonality in goats. For polymorphic RsaI cleavage site at base position 53, only genotype RR (267 bp/267 bp) was detected in Jining Grey goats, both genotype RR and genotype Rr (267 bp/320 bp) were found in all other goat breeds, no genotype rr (320 bp/320 bp) was detected in all six goat breeds. Frequency of genotype RR was obviously higher, and frequency of genotype Rr was obviously lower in year-round estrous goat breeds than in seasonal estrous goat breeds. Sequencing revealed one mutation (G52A) in genotype Rr compared with genotype RR. For polymorphic RsaI cleavage site, the differences of genotype distributions were significant (P<0.05) between year-round estrous goat breeds and seasonal estrous goat breeds. These results preliminarily showed an association between genotype RR and year-round estrus in goats, and an association between genotype Rr and seasonal estrus in goats.

Wnt/beta-catenin signaling modulates survival of high glucose-stressed mesangial cells

Glomerulosclerosis and diabetic nephropathy are attributable to high glucose induction of mesangial cell apoptosis. Whereas Wnt signaling has been found to regulate renal morphogenesis and pathogenesis, the biologic role of Wnt/beta-catenin signaling in controlling high glucose-induced mesangial cell apoptosis is not well defined. Herein is reported that Wnt/beta-catenin signaling is required for protecting glomerular mesangial cells from high glucose-mediated cell apoptosis. High glucose downregulated Wnt4 and Wnt5a expression and the subsequent nuclear translocation of beta-catenin, whereas it increased glycogen synthase kinase-3beta (GSK-3beta) and caspase-3 activities and apoptosis of glomerular mesangial cells. Suppression of GSK-3beta activation or increase in nuclear beta-catenin by transfection of Wnt4 or Wnt5a or stable beta-catenin (S33Y) reversed Akt activation and reduced the high glucose-mediated caspase-3 cleavage and cell apoptosis. Pharmacologic inhibition of GSK-3beta by recombinant Wnt5a or bromoindirubin-3'-oxime or LiCl increased Akt phosphorylation and beta-catenin translocation and abrogated high glucose-mediated proapoptotic activities. Exogenous bromoindirubin-3'-oxime treatment reduced phospho-Ser(9)-GSK-3beta and beta-catenin expression and apoptosis of cells adjacent to glomeruli in diabetic kidneys and attenuated urinary protein secretion in diabetic rats. Taken together, mesangial cells responded to high glucose by impairing that canonical Wnt pathway to increase proapoptotic activities. Sustaining Wnt/beta-catenin signaling is beneficial for promoting survival of mesangial cells that are exposed to high glucose stress.

MHC haplotypic association in Chinese Han patients with vitiligo

BACKGROUND

Serological typing of the human leucocyte antigen (HLA) has shown discrepancies in HLA associations with vitiligo in different ethnic populations.

OBJECTIVE

To evaluate the distributions of HLA at class I and II loci that may contribute to the genetic susceptibility of vitiligo patients in Chinese Hans population.

METHODS

We analysed the allelic frequencies of HLA class I and II by using the polymerase chain reaction sequence-specific primer (PCR-SSP) method in 187 patients with vitiligo and 273 controls in Chinese Hans. The linkage disequilibrium was calculated from a 2 x 2 table.

RESULTS

Two-locus haplotypes including HLA-A25-B13, HLA-A25-B27, HLA-A25-Cw*0602, HLA-A25-DQA1*0302, HLA-A25-DQA1*0601, HLA-A25-DQB1*0303, HLA-B13-Cw*0602, HLA-B13-DQA1*0302, HLA-B13-DQA1*0601, HLA-B27-Cw*0602, HLA-B27-DQA1*0302, HLA-B27-DQA1*0601, HLA-B27-DQB1*0303, HLA-B27-DQB1*0503, HLA-Cw*0602-DQA1*0302, HLA-Cw*0602-DQA1*0601, HLA-Cw*0602-DQB1*0303, HLA-Cw*0602-DQB1*0503 and HLA-DQA1*0302-DQB1*0503 were associated with all types of vitiligo in Chinese Hans. The extended haplotypes HLA-A25-B13-Cw*0602, HLA-A25-B27-Cw*0602, HLA-DQA1*0302-DQB1*0303-Cw*0602 and HLA-B13-DQB1*0303-Cw*0602 were found to be associated with all types of vitiligo in Chinese Hans, whereas the frequency of HLA-A25-Cw*0602-DQA1*0302 was significantly increased in generalized vitiligo but not in localized vitiligo. The frequencies of HLA-A25-DQA1*0302-DQB1*0503 and HLA-A30-DQA1*0302-DQB1*0303 were higher in childhood vitiligo than in adult vitiligo, and the frequency of HLA-A25-B13-DQB1*0303-Cw*0602 was shown to be associated with adult vitiligo but not childhood vitiligo.

CONCLUSION

This study demonstrates not only the differential association between HLA markers and types of vitiligo according to distribution or age at onset but also newly found high-risk haplotypes in Chinese vitiligo patients.

Recognising tuberculosis in the lower lung field: an age- and sex-matched controlled study

OBJECTIVE

Tuberculosis (TB) can sometimes present with consolidation in the lower lung field. This study was conducted to compare the manifestations of lower-lung-field TB (LLFTB) and other pulmonary TB.

DESIGN

All new culture-proven TB patients with lower-lung-field consolidation from July 2001 through December 2002 were included. Age- and sex-matched TB patients with upper lung involvement were selected as controls.

RESULTS

A total of 79 patients with LLFTB were included. Their mean age was 58.8 years; 46 were male. The clinical, radiographic and laboratory findings were similar in the LLFTB and the control groups, except that the LLFTB patients had less cavitation (P = 0.005). Patients with LLFTB were diagnosed (P = 0.051) and treated (P = 0.001) later than the control patients. The calibres of the trachea and both main bronchi were significantly smaller in the LLFTB group (P < 0.001). More patients with LLFTB developed segmental or lobar atelectasis during follow-up (P = 0.028).

CONCLUSIONS

The manifestations of LLFTB are non-specific. The lower-lung involvement, the lower incidence of cavitation and the higher probability of segmental or lobar atelectasis implied that LLFTB was primary TB. A small bronchial calibre probably contributed to its development.

Impact of the cyclin D1 A870G polymorphism on susceptibility to sporadic colorectal cancer in Taiwan

PURPOSE

Cyclin D1 is a regulatory protein involved in the cell cycle of both normal and neoplastic cells. Polymorphism of this gene at codon 242 in exon 4 has impacts on risk of the early-age onset in several malignant neoplasms, including colorectal cancer. This investigation was designed to evaluate the effect of cyclin D1 gene polymorphism on the risk of colorectal cancer in Chinese migrants of the Taiwanese population.

METHODS

We enrolled 831 primary sporadic colorectal cancer patients as the study group and 1,052 age-gender matched healthy individuals as the control group (1,883 total cases) for present study. Cyclin D1 genotypes (AA, AG, GG) were determined using PCR-RFLP analysis on genomic DNA.

RESULTS

The frequency of G allele was 39.89 percent and 40.96 percent in the study group and the control group, respectively (P = 0.02). The patients were divided into three age groups for statistical analysis. The younger male patients had a higher frequency of AA/AG genotype compared with the controls (odds ratio, 2.75; 95 percent confidence interval, 1-7.9). The effect of AA/AG genotype on colorectal cancer risk was statistically significant for male patients (odds ratio, 1.34; 95 percent confidence interval, 1.04-1.72), but such phenomenon was not observed in female patients.

CONCLUSIONS

Our study suggests that the effect of cyclin D1 gene polymorphism on colorectal cancer risk is only observed in males and AA/AG genotype of cyclin D1 gene is associated with a higher risk of colorectal cancer in the younger patients within the Taiwanese population.

Quantitative Analysis of Electron Field-Emission Characteristics of Individual Carbon Nanotubes: The Importance of the Tip Structure

Electron field-emission measurements on individual carbon nanotubes (CNTs) were performed inside the transmission electron microscope (TEM). The field-emission characteristics of CNTs with different tip structures were compared, and their field conversion factor and emission area were studied systematically. It was found that the field-emission characteristics of a CNT depend sensitively on its tip structure, and in particular an opened CNT was shown to be superior to a capped CNT. High-resolution TEM observations revealed that the tip of an opened CNT may, in general, be regarded as being composed of irregular shaped graphitic sheets, and these graphitic sheets have been found to improve dramatically the field-emission characteristics, but the sharp edge may result in larger error in the calculated emission area. The influence of uncertainty in the work function of the CNTs on the field conversion factor and emission area calculation was also investigated.

In Situ Fabrication and Graphitization of Amorphous Carbon Nanowires and Their Electrical Properties

Individual amorphous carbon nanowires (a-CNWs) were fabricated inside a transmission electron microscope (TEM) by the electron beam induced deposition (EBID) method, and the a-CNWs were graphitized in situ by introducing Fe particles into these a-CNWs and controlled movement of the Fe particles in these CNWs. Detailed structural characterizations and electrical measurements were carried out, and it was found that the current-induced movement of Fe particles has significant effects in purifying the as-fabricated a-CNW, transforming the a-CNW into a graphitized-CNW (g-CNW). Two-terminal current voltage characteristics measurements showed that the g-CNW has a very good electrical conductivity with a resistivity of about 5.3 x 10(-4) Omega cm, a current carrying capacity of at least 4.35 mA, and a current density of 4.6 x 10(8) A/cm(2), and these values are comparable to those of multiwalled carbon nanotubes. Field emission characteristics of both a-CNWs and g-CNWs were also measured, and their respective Fowler-Nordheim plots were found to have basically a linear form.

Delayed ischemic gangrene change of distal limb despite optimal decompressed colostomy constructed in obstructed sigmoid colon cancer: A case report

Creating blow-hole colostomy for decompression could provide a time-saving and efficient surgical procedure for a severely debilitated case with a completely obstructed colorectal cancer. Complications are reported as prolapse, retraction, and paracolostomal abscess. However, complication with an ischemic distal limb has not been reported. We report a case of critical intra-abdominal disease after decompressed colostomy for relieving malignant sigmoid colon obstruction; a potential fatal condition should be alerted. A 76-year-old male visited our emergency department for symptoms related to obstructed sigmoid colon tumor with foul-odor vomitus containing fecal-like materials. An emergent blow-hole colostomy proximal to an obstructed sigmoid lesion was created, and resolution of complete colon obstruction was pursued. Unfortunately, extensive abdominal painful distention with board-like abdomen and sudden onset of high fever with leukocytopenia developed subsequently. Such surgical abdomen rendered a secondary laparotomy with resection of the sigmoid tumor along with an ischemic colon segment located proximally up to the previously created colostomy. Eventually, the patient had an uneventful postoperative hospital stay. In the present article, we have described an emergent condition of sudden onset of distal limb ischemia after blow-hole colostomy and concluded that despite the decompressed colostomy would resolve acute malignant colon obstruction efficiently; impending ischemic bowel may progress with a possible irreversible peritonitis. Any patient, who undergoes a decompressed colostomy without resection of the obstructed lesion, should be monitored with leukocyte count and abdominal condition survey frequently.

Clinical outcome of intersphincteric resection for ultra-low rectal cancer

AIM: To analyze oncological outcome of intersphincteric resection (ISR) in ultra-low rectal cancer with intent to spare colostoma.

METHODS: From 1995 to 1998, patients with a non-fixed rectal adenocarcinoma (tumor stage T2) preserving the lower margin at 1-3 cm above the dentate line without distant metastasis was enrolled (period I). ISR was practiced in eight patients, and their postoperative follow-up was at least 5 years. In addition, from 1999 to 2003, another 10 patients having the same tumor location as period I underwent ISR (period II). Among those, 6 patients with T3-4-staged tumor received preoperative chemoradiotherapy.

RESULTS: All patients received ISR with curative intention and no postoperative mortality. In these case series at period I, local recurrence rate was 12.5% and metastasis rate 25.0%; the 5-year survival rate was 87.5% and disease-free survival rate 75.0%. There was no local recurrence or distant metastases in 10 patients with a median follow-up of 30 (range, 18-47) mo at period II.

CONCLUSION: As to ultra-low rectal cancer, intersphincteric resection could provide acceptable local control and cancer-related survival with no permanent stoma in early-staged tumor (tumor stage T2); moreover, preoperative concurrent chemoradiotherapy would make ISR feasible with surgical curative intent in more advanced tumors (tumor stages T3-4).

Management of patients with stercoral perforation of the sigmoid colon: Report of five cases

To our knowledge, stercoral perforation of the colon is rarely seen with fewer than 90 cases reported in the literature till date. We explored the principles of management to prevent impending mortality in five patients with this condition. Five patients, two males and three females, whose median age was 64 years, had sustained stercoral perforation of the sigmoid colon. Chronic constipation was the common symptom among these patients. Three patients underwent a Hartmann’s procedure and another two were treated with segmental colectomy with anastomosis and diverting colostomy. There was one surgical mortality and the other patients had an uneventful hospital stay. Timely intervention to prevent and/or treat any associated sepsis along with extensive peritoneal lavage and surgical intervention to remove diseased colonic tissue at the primary stercoral ulceration site coupled with aggressive therapy for peritonitis are key treatment modalities in salvaging patients presenting with stercoral perforation of the colon.

Evaluation of contrast-enhanced computed tomographic colonography in detection of local recurrent colorectal cancer

AIM: To evaluate the diagnostic accuracy, sensitivity, specificity of contrast-enhanced computed tomographic colonography in detecting local recurrence of colorectal cancer.

METHODS: From January 2000 to December 2004, 434 patients after potentially curative resection for invasive colorectal cancer were followed up for a period ranging from 20 to 55 mo. Eighty of the four hundred and thirty-four patients showing strong clinical evidence for recurring colorectal cancer during the last follow-up were enrolled in this study. Each patient underwent contrast-enhanced computed tomographic colonography and colonoscopy on the same day. Any lesions, biopsies, identified during the colonoscopic examination, immediate complications and the duration of the procedure were recorded. The results of contrast-enhanced computed tomographic colonography were evaluated by comparing to those of colonoscopy, surgical finding, and clinical follow-up.

RESULTS: Contrast-enhanced computed tomographic colonography had a sensitivity of 100%, a specificity of 83% and an overall accuracy of 94% in detecting local recurrent colorectal cancer.

CONCLUSION: Conventional colonoscopy and contrast-enhanced tomographic colonography can complement each other in detecting local recurrence of colorectal cancer.

The roles of different subtypes of opioid receptors in mediating the nucleus submedius opioid-evoked antiallodynia in a neuropathic pain model of rats

Previous studies have indicated that thalamic nucleus submedius is involved in opioid-mediated antinociception in tail flick test and formalin test. The current study examined the effects of opioids microinjected into the thalamic nucleus submedius on the allodynia developed in neuropathic pain model rats, and determined the roles of different subtypes of opioid receptors in the thalamic nucleus submedius opioid-evoked antiallodynia. The allodynic behaviors induced by L5/L6 spinal nerve ligation were assessed by mechanical (von Frey filaments) and cold (4 degrees C plate) stimuli. Morphine (1.0, 2.5, and 5.0 microg) microinjected into the thalamic nucleus submedius contralateral to the nerve injury paw produced a dose-dependent inhibition of the mechanical and cold allodynia, and these effects were reversed by microinjection of the non-selective opioid receptor antagonist naloxone (1.0 microg) into the same site. Microinjection of endomorphin-1 (5.0 microg), a highly selective mu-opioid receptor agonist, and [D-Ala2, D-Leu5]-enkephalin (10 microg), a delta-/mu-opioid receptor agonist, also inhibited the allodynic behaviors, and these effects were blocked by selective mu-opioid receptor antagonist beta-funaltrexamine hydrochloride (3.75 microg). However, the [D-Ala2, D-Leu5]-enkephalin-evoked antiallodynic effects were not influenced by the selective delta-opioid receptor antagonist naltrindole (5.0 microg). Microinjection of the selective kappa-receptor agonist spiradoline mesylate salt (100 microg) into the thalamic nucleus submedius failed to alter the allodynia induced by spinal nerve ligation. These results suggest that the thalamic nucleus submedius is involved in opioid-evoked antiallodynia which is mediated by mu- but not delta- and kappa-opioid receptor in the neuropathic pain model rats.

Efficient diode-pumped actively Q-switched Nd:YAG/BaWO4 intracavity Raman laser

Barium tungstate (BaWO4) is employed to achieve efficient stimulated Raman scattering conversion in a compact diode-pumped actively Q-switched Nd:YAG laser. With an incident pump power of 9.2 W, 1.56 W of 1181 nm first-Stokes average output power was generated at a pulse repetition rate of 20 kHz, corresponding to an optical-to-optical conversion efficiency of 16.9%.

Natural attenuation of MTBE at two petroleum-hydrocarbon spill sites

Methyl tert-butyl ether (MTBE) has been used as a gasoline additive to improve the combustion efficiency and to replace lead since 1978. Because it is widely used and it has been disposed inappropriately, MTBE has become a prevalent groundwater contaminant worldwide. In this study, two petroleum-hydrocarbon contaminated sites (Sites A and B) were selected to evaluate the occurrence and effectiveness of natural attenuation of MTBE at these two sites. Field investigation results indicate that the natural attenuation mechanisms of MTBE at both sites were occurring with the first-order attenuation rates of 0.0021 and 0.0048 1day(-1) at Sites A and B, respectively. Results also reveal that the intrinsic biodegradation pattern was the most important mechanism among the natural attenuation processes at both sites. Results from BIOSCREEN simulation suggest that biodegradation was responsible for 78 and 59% of MTBE mass reduction at Sites A and B, respectively. Investigation results show that MTBE plume at Site B could be effectively controlled via natural attenuation processes. However, MTBE plume at Site A has migrated to a farther downgradient area and passed the boundary line of the site. Thus, more active groundwater remedial technologies should be applied at Site A to protect the downgradient environment. Results from this study suggest that natural attenuation might be feasible to be used as a remedial option for the remediation of MTBE-contaminated site on the premise that (1) detailed site characterization has been conducted and (2) the occurrence and effectiveness of natural attenuation processes have been confirmed.