[Multivariate analysis and construction and validation of a nomogram model from data of 1610 patients with non-tumor-related anastomotic stenosis after rectal cancer surgery].

Objective: To assess the risk factors affecting development of non-tumor- related anastomotic stenosis after rectal cancer and to construct a nomogram prediction model. Methods: This was a retrospective study of data of patients who had undergone excision with one-stage intestinal anastomosis for rectal cancer between January 2003 and September 2018 in Nanfang Hospital of Southern Medical University. The exclusion criteria were as follows: (1) pathological examination of the operative specimen revealed residual tumor on the incision margin of the anastomosis; (2) pathological examination of postoperative colonoscopy specimens revealed tumor recurrence at the anastomotic stenosis, or postoperative imaging evaluation and tumor marker monitoring indicated tumor recurrence; (3) follow-up time <3 months; and (4) simultaneous multiple primary cancers. Univariate analysis using the χ2 or Fisher's exact test was performed to assess the study patients' baseline characteristics and variables such as tumor-related factors and surgical approach (P<0.05). Multivariate analysis using binary logistic regression was then performed to identify independent risk factors for development of non-tumor-related anastomotic stenosis after rectal cancer. Finally, a nomogram model for predicting non-tumor-related anastomotic stenosis after rectal cancer surgery was constructed using R software. The reliability and accuracy of this prediction model was evaluated using internal validation and calculation of the area under the curve of the model's receiver characteristic curve (ROC). Results: The study cohort comprised 1,610 patients, including 1,008 men and 602 women of median age 59 (50, 67) years and median body mass index 22.4 (20.2, 24.5) kg/m². Non-tumor-related anastomotic stenosis developed in 121 (7.5%) of these patients. The incidence of non-tumor-related anastomotic stenosis in patients who had undergone neoadjuvant chemotherapy, neoadjuvant radiotherapy, and surgery alone was 11.2% (10/89), 26.4% (47/178), and 4.8% (64/1,343), respectively. Neoadjuvant treatment (neoadjuvant chemotherapy: OR=2.455, 95%CI: 1.148-5.253, P=0.021; neoadjuvant chemoradiotherapy, OR=3.882, 95%CI: 2.425-6.216, P<0.001), anastomotic leakage (OR=7.960, 95%CI: 4.550-13.926, P<0.001), open laparotomy (OR=3.412, 95%CI: 1.772-6.571, P<0.001), and tumor location (distance of tumor from the anal verge 5-10 cm: OR=2.381, 95%CI:1.227-4.691, P<0.001; distance of tumor from the anal verge <5 cm: OR=5.985,95% CI: 3.039-11.787, P<0.001) were identified as independent risk factors for non-tumor-related anastomotic stenosis. Thereafter, a nomogram prediction model incorporating the four identified risk factors for development of anastomotic stenosis after rectal cancer was developed. The area under the curve of the model ROC was 0.815 (0.773-0.857, P<0.001), and the C-index of the predictive model was 0.815, indicating that the model's calibration curve fitted well with the ideal curve. Conclusion: Non-tumor-related anastomotic stenosis after rectal cancer surgery is significantly associated with neoadjuvant treatment, anastomotic leakage, surgical procedure, and tumor location. A nomogram based on these four factors demonstrated good discrimination and calibration, and would therefore be useful for screening individuals at risk of anastomotic stenosis after rectal cancer surgery.

An expert consensus for the management of chronic hepatitis B in Asian Americans.

BACKGROUND: Hepatitis B virus (HBV) infection is common with major clinical consequences. In Asian Americans, the HBsAg carrier rate ranges from 2% to 16% which approximates the rates from their countries of origin. Similarly, HBV is the most important cause of cirrhosis, hepatocellular carcinoma (HCC) and liver related deaths in HBsAg positive Asians worldwide. AIM: To generate recommendations for the management of Asian Americans infected with HBV. METHODS: These guidelines are based on relevant data derived from medical reports on HBV from Asian countries as well as from studies in the HBsAg positive Asian Americans. The guidelines herein differ from other recommendations in the treatment of both HBeAg positive and negative chronic hepatitis B (CHB), in the approach to HCC surveillance, and in the management of HBV in pregnant women. RESULTS: Asian American patients, HBeAg positive or negative, with HBV DNA levels >2000 IU/mL (>104 copies/mL) and ALT values above normal are candidates for anti-viral therapy. HBeAg negative patients with HBV DNA >2000 IU/mL and normal ALT levels but who have either serum albumin <3.5 g/dL or platelet count <130 000 mm3 , basal core promoter (BCP) mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive life-long anti-viral therapy. Indications for treatment include pregnant women with high viraemia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg positive patients with risk factors, life-long surveillance for HCC with alpha-fetoprotein (AFP) testing and abdominal ultrasound examination at 6-month intervals is required. In CHB patients receiving HCC treatments, repeat imaging with contrast CT scan or MRI at 3-month intervals is strongly recommended. These guidelines have been assigned to a Class (reflecting benefit vs. risk) and a Level (assessing strength or certainty) of evidence. CONCLUSIONS: Application of the recommendations made based on a review of the relevant literature and the opinion of a panel of Asian American physicians with expertise in HBV treatment will inform physicians and improve patient outcomes.

Incorporation of quantum dots in silk biomaterials for fluorescence imaging.

Tracking the distribution and degradation of biomaterials after in vivo implantation or injection is important for tissue engineering and drug delivery. Intrinsic and externally labeled fluorescence has been widely used for these purposes. In the present study, 3-mercaptopropionic acid (MPA)-coated CdTe quantum dots (QDs) were incorporated into silk materials via strong interactions between QDs and silk, likely involving the hydrophobic beta-sheet structures in silk. MPA-QDs were pre-mixed with silk solution, followed by ultrasonication to induce silk gelation or by blending with polyvinyl alcohol (PVA) to generate silk microspheres. Silk structural changes and hydrogel/microsphere morphologies were examined by ATR-FTIR and SEM, respectively. The fluorescence of QDs-incorporated silk hydrogels and microspheres remained stable in PBS pH 7.4 for more than 4 days. The amount of QDs released from the materials during the incubation was dependent on loading; no QDs were released when loading was below 0.026 nmol/mg silk. After subcutaneous injection in mice, the fluorescence of QDs-incorporated silk microspheres was quenched within 24 h, similar to that of free QDs. In contrast, the QDs-incorporated silk hydrogels fluoresced for more than 4 days in vivo.

Accelerated gallstone dissolution in methyl tert-butyl ether by sonication. An in vitro study.

OBJECTIVES: The authors tested the effect of 195 KHz therapeutic ultrasound energy on gallstone dissolution in concert with methyl tert-butyl ether (MTBE) in vitro. METHODS: Sixteen sets of three gallstones matched for weight and appearance were selected from 16 surgically resected human gallbladders. One stone from each set was analyzed for its density pattern by computed tomography (CT) and biochemically for cholesterol content. Based on CT appearance, the stones were classified into eight noncalcified, four partially calcified, and four heavily calcified sets. The three stones were subjected to dissolution with MTBE: one with simultaneous sonication via an experimental ultrasound unit, one with manual stirring, and one acted as control without added treatment. RESULTS: Sonication reduced the dissolution time of noncalcified stones by 96% (range, 94%-98%; standard deviation [SD], 2%) relative to controls, and it was three to four times more effective than manual stirring. It was similarly effective in helping to dissolve partially calcified stones, but not heavily calcified stones. CONCLUSIONS: This study demonstrates the positive effect of sonication in accelerating gallstone dissolution with MTBE in vitro for stones without heavy calcification.

In vivo cancellous bone remodeling on a strontium-containing hydroxyapatite (sr-HA) bioactive cement.

The purpose of this study was to investigate the in vivo bone response to the strontium-containing hydroxyapatite (Sr-HA) bioactive bone cement injected into the cancellous bone. Sr-HA cement was injected into the iliac crest of rabbits for 1, 3, and 6 months. Active bone formation and remodeling were observed after 1 month. Newly formed bone was observed to grow onto the bone cement after 3 months. Thick osteoid layer with osteoblasts formed along the bone and guided over the bone cement surface reflected the stimulating effect of Sr-HA. From scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis, high calcium and phosphorus levels were detected at the interface with a thick layer of 70 microm in width, and fusion of Sr-HA with the bone was observed. Blood vessels were found developing in remodeling sites. The affinity of bone on Sr-HA cement was increased from 73.55 +/- 3.50% after 3 months up to 85.15 +/- 2.74% after 6 months (p < 0.01). In contrast to Sr-HA cement, poly(methyl methacrylate) (PMMA) bone cement was neither osteoconductive nor bioresorbable. Results show that the Sr-HA cement is biocompatible and osteoconductive, which is suitable for use in treating osteoporotic vertebral fractures.

In vitro evaluation of gallstone dissolution with methyl-tert-butyl ether and ultrasound energy.

Given the large number of cholecystectomies performed annually, a nonsurgical approach to gallstone therapy is of great interest. A laboratory ultrasound system has been developed to study enhancement of methyl-tert-butyl ether (MTBE) dissolution of human gallstones in vitro. A mathematical model that quantitatively characterizes the dissolution process via a rate constant has been developed. Using this model, the kinetics of 15 gallstones from a single patient were evaluated for three dissolution methods: 1) unstirred MTBE, 2) aspirated MTBE, and 3) ultrasonically enhanced MTBE. The results showed excellent fits between the model and measured dissolution rates. 195 kHz continuous-wave (CW) ultrasonically enhanced dissolution rates exhibited a 6.2 fold gain over the manually aspirated MTBE and a 49.5 fold gain over static MTBE dissolution. Investigation of 50% duty cycle pulsed mode ultrasound revealed that total power appears to be the determinant of the observed dissolution rates. Gallstone calcification showed a strong correlation with dissolution rates measured by the model.

Effects of chondroitinase ABC and chymopapain on spinal motion segment biomechanics. An in vivo biomechanical, radiologic, and histologic canine study.

STUDY DESIGN: The biomechanical effects of chondroitinase ABC and chymopapain related to spinal segmental instability were investigated using a canine model, as well by as radiologic and histologic analyses. OBJECTIVES: To evaluate the biomechanical, radiologic, and histologic affects on the lumber intervertebral disc of chondroitinase ABC compared with chymopapain. SUMMARY OF BACKGROUND DATA: No study on the biomechanical effects of chondroitinase ABC has been reported. METHODS: Forty-eight lumbar intervertebral discs in eight beagles were randomly assigned to three groups and received one of three materials: chondroitinase ABC, chymopapain, or buffered saline, using a lateral percutaneous procedure. One week after injection, the animals were killed and the lumbar spinal motion segments were removed. Spinal segmental instability after chemonucleolysis was evaluated in spinal motion segments without posterior elements. Radiologic and histologic changes were also investigated. RESULTS: Spinal segmental instability and disc space narrowing were more greater in the chymopapain group than in the chondroitinase ABC group. Destruction of nucleus and anulus proteoglycans, indicated by loss of safranin-O staining, was less intense in chondroitinase ABC-injected discs. CONCLUSIONS: Chondroitinase ABC results in less spinal segmental instability, disc space narrowing, and destruction of proteoglycans in intervertebral disc matrix than chymopapain.

Assessment of scoliosis correction in relation to flexibility using the fulcrum bending correction index.

STUDY DESIGN: A prospective study on adolescent idiopathic scoliosis to assess a new method of describing frontal plane correction. OBJECTIVE: To assess the difference between using the correction rate and using the new fulcrum bending correction index when describing scoliosis correction. SUMMARY OF BACKGROUND DATA: A description of the outcome of scoliosis surgery based on the correction rate does not take into account the curve's flexibility. METHODS: The fulcrum bending correction index is calculated by dividing the correction rate by the fulcrum flexibility (based on the fulcrum bending radiograph) and is expressed as a percentage. The fulcrum bending correction index was compared with the correction rate in 35 patients with adolescent idiopathic scoliosis undergoing surgical correction. These patients were divided into a stiff and a flexible group based on a fulcrum flexibility of 50% to show the advantage of the fulcrum bending correction index over the correction rate. RESULTS: The difference in correction rate between the flexible (66%) and the stiff group (45%) was significant (P < 0.05). The difference in the fulcrum bending correction index between the flexible (96%) and the stiff group (107%) was not significant (P = 0.2). CONCLUSIONS: The fulcrum bending correction index takes into account the curve flexibility and is therefore better than the correction rate for comparing curve correction and use of instrumentation systems between different series of patients. A fulcrum bending correction index of close to 100% suggests that the instrumentation has taken up all the flexibility revealed by the fulcrum bending radiograph. It is recommended that the fulcrum bending correction index be used in the future as part of the postoperative assessment of frontal plane correction in cases of thoracic scoliosis.

MR-guided therapy. Applications in the abdomen.

This article provides an overview of current abdominal interventional applications that use MR imaging guidance and monitoring for diagnostic biopsies, tumor ablations and--owing to the development of new pulse sequences--monitoring the ablation process, and aspiration and drainage of fluid collections. These applications are optimal for patients with lesions that can be localized only by MR imaging or for lesions in suboptimal locations such as the dome of the liver.

[A sarcoma-static new species of Pseudomonas, Pseudomonas jinanensis sp. nov].

A strain of Gram negative bacteria was isolated from the surface soil of Wuying Hill at Jinan, Shandong province with Gause's medium in 1973. It is a strain of antagonistic bacteria for hysterocervicoma, hepatoma and melanoma of mice screened from 2100 strains of bacteria. It is also antagonistic to Staphylococcus aureus, Bacillus subtilis and Micrococcus. It is a Gram negative bacterium with lophotrichous polar flagella. Straight rods in shape or with a little slightly curved rods, 0.5-0.6 X 1-2 microns, randomly arranged, poly-beta-hydroxybutyrate granules are accumulated in cells after 2-5 days cultivation. Water green soluble pigment and green fluorescent pigment are produced. Respiratory metabolism, chemoorganotroph, many carbon-containing organic compounds can be used as carbon sources, such as glucose, trehalose, ethanol, cellulobiose, fucose, arginine and betaine, but propionic acid or tartaric acid is not utilized. Inorganic nitrogen containing compounds can be used ae the sole source of nitrogen. No growth factor is necessary for growth. Gelatin is hydrolyzed. Starch and cellulose are not hydrolyzed. Nitrate is not reduced. Arginine dihydrolase is produced. Levan is produced from sucrose. Growth occurs from 7 degrees C to 37 degrees C and from pH 5.65-8.40. No growth occurs at 40 degrees C and at pH value below 4.86. It can not grow autotrophically with hydrogen. Its G + C contents in DNA is 58.1 mol%. DNA-DNA hybridization experiments reveals a relatedness value of 58.6% between this strain and Ps. fluorescens. The above evidence shows that this strain differs from all species known in Pseudomonas, such as Pseudomonas fluorescens group. Pseudomonas caryophylli, Pseudomonas cepacia, Pseudomonas marginata, Pseudomonas acidovorans, Pseudomonas testosteroni and Pseudomonas delafieldii.(ABSTRACT TRUNCATED AT 250 WORDS)

Coupling between sagittal and frontal plane deformity correction in idiopathic thoracic scoliosis and its relationship with postoperative sagittal alignment.

STUDY DESIGN: Prospective clinical-radiographic study. OBJECTIVES: To investigate the natural coupling behavior between frontal deformity correction and the simultaneous changes in thoracic kyphosis, and to examine how the postoperative thoracic sagittal realignment relates to this natural coupling behavior. SUMMARY OF BACKGROUND DATA: Restoration of the sagittal alignment is one of the fundamental goals in scoliosis correction surgery. It is generally achieved by rod precontouring intraoperatively. However, clinical studies suggested that postoperative sagittal realignment seems to be more affected by the inherent properties of the spine rather than the instrumentation or the surgical maneuver. METHODS: Ninety-eight idiopathic scoliosis patients with thoracic curves treated with one-stage posterior spinal fusion, using corrective segmental spinal instrumentation (hook-rod or pedicle screw-rod constructs) were investigated. Pre- and postoperative frontal and sagittal alignments were measured by standing anteroposterior and lateral radiographs. Preoperative frontal plane flexibility was assessed by the fulcrum bending radiograph in the standard manner, an additional radiograph was taken in the lateral plane, to assess how this frontal correction force affects sagittal plane alignment (lateral fulcrum bending radiograph). RESULTS: When thoracic frontal deformity was corrected under fulcrum bending, coupled changes in the thoracic kyphosis demonstrated 3 different patterns: thoracic kyphosis increased in 25 patients with a mean kyphosis of 9 degrees to 19 degrees, decreased in 45 with a mean of 34 degrees to 21 degrees and remained unchanged (within 3 degrees ) in 28 with a mean of 19 degrees to 18 degrees. After surgery, the direction of correction of thoracic kyphosis significantly correlated with the coupling patterns demonstrated on fulcrum bending radiographs (r = 0.579, P < 0.001). However, the actual postoperative thoracic kyphosis angle cannot be predicted by the preoperative lateral fulcrum bending radiograph. There was no statistically significant difference (P = 0.263) between using pedicle screws and hooks in achieving the additional correction beyond what was demonstrated on the lateral fulcrum bending radiographs. CONCLUSION: Changes in thoracic kyphosis on fulcrum bending due to natural coupling of deformities are directed towards "self-normalization." There is no difference in the sagittal plane deformity correction with the use of hook-rod system or pedicle screw-rod constructs. This can be used as a guideline for exact preoperative rod contouring to reduce the stress on the bone-implant interface and the rate of postoperative failures. The findings also suggest that it is not how big or strong the implants are, but rather the natural curve behavior will at least partially determine the final sagittal outcome.

Synergistic effect in treatment of C.I. Acid Red 2 by electrocoagulation and electrooxidation.

An aqueous C.I. Acid Red 2 solution was decolorized by electrolysis using iron as anode. The decolorization mechanism was investigated through experimental observations on the electrochemical behavior of C.I. Acid Red 2 on Pt rotating disk electrode, UV-visible spectra of the solution and IR spectra of the coagulated mixtures. It is found that the decolorization efficiency is high, over 98.0% after 40 min, and this high decolorization efficiency can be ascribed to the synergistic effect of electrocoagulation and electrooxidation. The electrocoagulation results from the electrogenerated iron hydroxide and the electrooxidation results from electrogenerated ferric ions. The results obtained from IR spectra shows that the decolorization of C.I. Acid Red 2 by electrooxidation is due to the partial or complete cleavage of C-N bonds in C.I. Acid Red 2.

Changes in melatonin receptors in relation to the development of scoliosis in pinealectomized chickens.

STUDY DESIGN: The 2[125I]iodomelatonin binding assay was used to investigate the involvement of melatonin receptors in the development of scoliosis in pinealectomized chickens. OBJECTIVE: To compare the binding properties of melatonin receptors in the thoracic spinal cord between pinealectomized chickens that had scoliosis develop and those that did not. SUMMARY OF BACKGROUND DATA: Surgical pinealectomy in young chickens induced scoliosis with a reported incidence of 50% to 100%. The factors regulating the development of scoliosis in this animal model are unclear. Melatonin receptors have been shown in the spinal cord of chickens, but their functions are still unknown. This study addresses the question as to whether spinal cord melatonin receptors are related to the pathogenesis of scoliosis in pinealectomized chickens. METHOD: Control and pinealectomized chickens were kept under controlled lighting conditions and monitored for scoliosis development. At 9-11 weeks after pinealectomy, thoracic spinal cords were removed for 2[125I]iodomelatonin binding assay, and blood was collected for serum melatonin assay at either the middle of the light period or middle of the dark period. RESULTS: Pinealectomy in young chickens produced: (1) loss of diurnal variations in serum melatonin levels, (2) 50% incidence of scoliosis, and (3) attenuation in the diurnal variations in the receptor affinity to melatonin. No differences were detected in the serum melatonin levels or binding of spinal cord melatonin receptors between the pinealectomized chickens that had scoliosis develop and those that did not. CONCLUSION: Changes are detected in melatonin receptor binding after pinealectomy. However, these changes cannot account for the reason why scoliosis develops in some chickens after pinealectomy, while it does not in others. Neither low melatonin serum level nor changes in spinal cord melatonin binding can be a sole etiologic factor in the pathogenesis of scoliosis in pinealectomized chickens.

Effect of segmental artery ligation on the blood supply of the thoracic spinal cord during anterior spinal surgery: a quantitative histomorphological fresh cadaver study.

STUDY DESIGN: Human cadaver quantitative morphometric analysis of the blood vessels in the spinal cord after ligation of segmental arteries. OBJECTIVES: To investigate the effect of ligation of segmental arteries on the quantity and density of the blood vessels in the spinal cord. SUMMARY OF BACKGROUND DATA: Ligation of segmental arteries is often used in the anterior approach for correction scoliosis. However, whether or not segmental artery ligation is liable to deny the spinal cord an adequate blood supply, thus leading to paraplegia, still remains controversial. METHODS: Eleven fresh cadavers were divided into control, unilateral, and bilateral groups. For the unilateral and bilateral groups, 5 segmental vertebral arteries (T7-T11) were ligated unilaterally and bilaterally, respectively. Then, the number and density of blood vessels at different levels in the 3 groups were measured. RESULTS: Compared to that of the corresponding level in the control group, the number of blood vessels at T5 to L1 all decreased in the ligation groups. And significant differences were found at T8 (82.80 +/- 16.36), T10 (77.80 +/- 19.80), and T11 (99.20 +/- 14.85) levels, compared to those of the corresponding levels in the control group: T8 (175.80 +/- 8. 31), T9 (176.40 +/- 32. 33), T10 (171.40 +/- 9. 73), and T11 (189.20 +/- 15. 92). Further decrease was found at each corresponding level in the bilateral group, and significant differences were found at T8 (65.80 +/- 15.55), T9 (24.80 +/- 13.43), T10 (0), T11 (0), and T12 (0) levels. Similar results were obtained with regard to the density of blood vessels. Significant differences were found at T11 (1.246 +/- 0.112) and L1 (1.349 +/- 0.109) in the unilateral group, and T9 (0.260 +/- 0.088), T10 (0), T11 (0), T12 (0), and L1 (0.147 +/- 0.117) in the bilateral group compared to those of the corresponding levels in the control group: T9 (1.810 +/- 0.202), T10 (1.833 +/- 0.175), T11 (2.308 +/- 0.335), T12 (2.510 +/- 0.617), and L1 (2.193 +/- 0.033). CONCLUSIONS: This study suggests that the more levels the ligation encompasses, the higher the risk of spinal cord damage. Therefore, caution should be taken when several segmental arteries are to be ligated in the clinical setting. What is more, bilateral ligation, which is worse than unilateral ligation, can lead to a significant decrease in the number and density of blood vessels of the spinal.

Early enhancement of tumor thrombus in the portal vein on two-phase helical CT.

We report a case of hepatocellular carcinoma with a portal vein thrombus that showed early arterial enhancement of dual-phase helical CT, which permitted a specific diagnosis of tumor portal venous thrombus.

Helical computed tomography for abdominal imaging.

Significant technologic advances have taken place in computed tomography (CT). Current-generation conventional CT scanners are able to image a slice of tissue in as little as 2 to 3 seconds and can acquire several consecutive images. Although it is a substantial improvement from the CT of 5 years ago, there remain practical limits to the utility of conventional CT imaging within the abdomen. Recently, a new type of CT gantry design ("slip-ring") and faster computers have contributed to the development of a new generation of CT scanners, the "helical" or "spiral" CT scanners.

Mechanism of depressed immunity in chronic renal failure: effect of cyclophosphamide pretreatment on delayed-type hypersensitivity skin reaction.

An imbalance in immunoregulatory mechanisms resulting in a relative increase in suppressor cell activity has been implicated in the development of the immunological deficit observed in chronic uremia. The present study was designed to assess whether cyclophosphamide pretreatment would preferentially enhance immune responses of chronically uremic animals. Delayed-type hypersensitivity (DTH) skin responses to oxazolone were found significantly decreased in chronically uremic mice as compared with sham-operated and normal controls. The administration of a single high dose (250 mg/kg) of cyclophosphamide 3 days prior to skin sensitization with oxazolone resulted in enhancement of DTH responses in all mice groups. Maximal increases in DTH responses following cyclophosphamide treatment was 61.6% in chronically uremic mice, and 100.5 and 86.2% in sham-operated and normal controls, respectively. The levels of active metabolites of cyclophosphamide, as estimated indirectly by the degree of myelosuppression achieved, were comparable across the 3 mice groups. These results thus fail to provide evidence for excessive numbers of cyclophosphamide-sensitive suppressor cells in chronic experimental uremia.