Heparin loading and pre-endothelialization in enhancing the patency rate of electrospun small-diameter vascular grafts in a canine model

We herein proved that the two commonly used antithrombotic methods, heparin loading and pre-endothelialization could both greatly enhance the patency rate of a small-diameter graft in a canine model. Tubular grafts having an inner diameter of 4 mm were prepared by electrospinning poly(l-lactide-co-ε-caprolactone) (P(LLA-CL)) and heparin through a coaxial electrospinning technique. Seventy-two percent of heparin was found to be released sustainably from the graft within 14 days. To prepare the pre-endothelialized grafts, we seeded endothelial cells isolated from the femoral artery and cultured then dynamically on the lumen until a cell monolayer was formed. Digital subtraction angiography (DSA) and color Doppler flow imaging (CDFI) were used to monitor the patency without sacrificing the animals. Histological analyses revealed that following the direction of blood flow, a cell monolayer was formed at the proximal end of the heparin-loaded grafts, but such a monolayer could be found in the middle or distal region of the grafts. In contrast, the whole luminal surface of the pre-endothelialized graft was covered by a cell monolayer, suggesting the in vivo survival of the preseeded cells. This demonstrated that heparin was a comparatively simple method to achieve good patency, but the pre-endothelialization had better mechanical properties and cellular compatibility.

Value of ¹⁸F-FDG PET/CT in the diagnosis of primary gastric cancer via stomach distension

OBJECTIVE

To clarify the usefulness of (18)F-FDG PET/CT for detecting primary gastric cancer via gastric distention using a mixture of milk and Diatrizoate Meglumine.

MATERIALS AND METHODS

A total of 68 patients (male: 47, female: 21; age: 41-87 years) suspected of gastric carcinoma underwent (18)F-FDG PET/CT imaging. After whole-body PET/CT imaging in a fasting state, the patients drank a measured amount of milk with Diatrizoate Meglumine. Local gastric district PET/CT imaging was performed 30 min later. The imaging was analyzed by semi-quantitative analysis, standardized uptake value (SUV) of the primary tumor was measured in a region of interest. The diagnosis results were confirmed by gastroscopy, pathology, and follow-up results.

RESULTS

Of the 68 patients, 56 malignant gastric neoplasm patients (male: 37, female: 19) were conformed. The sensitivity, specificity, positive predictive value and negative predictive value of fasting whole-body PET/CT imaging for a primary malignant tumor were 92.9%, 75.0%, 94.5%, and 69.0%, respectively. The values for distension with a mixture of milk and Diatrizoate Meglumine were 91.1%, 91.7%, 98.1%, and 68.8%, respectively. The area under the curve was 0.919 ± 0.033 and 0.883 ± 0.066 for the diagnosis of gastric cancer with SUVmax in a fasting state and after intake of mixture respectively, the differences were not statistically significant (P=0.359). Using gastric distension with a mixture of milk and Diatrizoate Meglumine, the mean ratio of the lesion's SUVmax to the adjacent gastric wall SUVmax increased significantly from 3.30 ± 3.05 to 13.50 ± 15.05, which was statistically significant (P<0.001).

CONCLUSIONS

(18)F-FDG PET/CT imaging is highly accurate for the diagnosis of primary gastric carcinoma. Gastric distention can display the lesions more clearly, however, it cannot significantly improve diagnostic accuracy.

Epigallocatechin gallate attenuates interstitial cystitis in human bladder urothelium cells by modulating purinergic receptors

BACKGROUND

Epigallocatechin gallate (EGCG) has exhibited antitumor properties against bladder cancer. However, its effects in interstitial cystitis (IC) have not been investigated.

METHODS

Here, we performed repeated cystoscopy and re-biopsy of bladder mucosa before and after intravesical irrigation of EGCG in eight patients diagnosed with IC based on clinical and histopathologic assessments. Six normal bladder tissue samples were obtained from age-, race-, and sex-matched asymptomatic control subjects. IC symptom index was used to compare the therapeutic effect in IC patients. Patient-derived bladder epithelial cells were cultured and cell stretch experiments and ATP assays were performed. The expression of purinergic receptors X1, X2, and X3, and Y1, Y2, and Y11, in biopsied samples was detected by Western blotting and real-time polymerase chain reaction, respectively. Moreover, the expression of inducible NO synthase, phosphorylated Akt, and phosphorylated NF-κB was also assessed.

RESULTS

All EGCG-treated patients demonstrated different extents of remission of symptoms. We found a significant upregulation in P2X1, P2X2, and P2X3 receptor proteins and P2Y1, P2Y2, and P2Y11 receptor transcripts in IC patients. However, EGCG therapy attenuated the expression of all purinergic receptors. In addition, EGCG demonstrated prominent antioxidative and antiinflammatory effects via inhibition of the upregulation of iNOS and phosphorylated NF-κB. Furthermore, the stretch-activated release of ATP in cultured bladder urothelial cells was greater in cells derived from IC patients, compared with those from the control patients, but EGCG, at all concentrations tested, effectively abolished the increase in ATP release from stretched IC patient-derived cells.

CONCLUSIONS

Our study suggests that inhibition of the expression of purinergic receptors and ATP release in urothelial cells by EGCG supports further development of EGCG as a novel therapeutic option for IC.

Effects of nicarbazin on the blood glucose and liver glycogen statuses of male broilers

Nicarbazin (NCZ), an effective anticoccidial widely used by the global broiler industry, is known to produce some side effects in broilers. Recent field observations have suggested that NCZ could be associated with spiking mortality syndrome, a disease of uncertain etiology that is most commonly characterized by hypoglycemia. In turn, 2 trials were conducted to investigate the effects of NCZ on the blood glucose levels and liver glycogen content of Ross × Ross 708 male broilers. In 6 of 12 pens beginning at 1 d of age, NCZ was added to basal broiler diets at a rate of 125 mg/kg, and the other 6 pens were control pens in which birds received salinomycin instead of NCZ, at a rate of 66 mg/kg. Feed and water were provided ad libitum, feed was closely monitored in all pens to avoid shortages, no coccidial challenge was imposed, and room temperature never exceeded 29.4°C. At the end of the second trial, a photoperiod increase from 8L:16D to 24L:0D was imposed in an effort to induce stress due to feed engorgement. In response to NCZ in trial 1, 0 to 28 d feed conversion and relative liver weights on d 21 and 28 were higher, whereas 0 to 28 d cumulative BW gain was lower. In response to NCZ in trial 2, 0 to 13 d feed conversion was higher, whereas 0 to 13 d cumulative BW gain was lower. The added NCZ increased blood glucose on d 13 in trial 2, but did not affect at any time the liver constituents analyzed in both trials. In conclusion, the uninterrupted feeding of NCZ at 125 mg/kg in the starter and grower diets of male Ross × Ross 708 broilers increased feed conversion and reduced BW gain, but despite an increase in relative liver weight on d 21 and 28 posthatch, liver glucose and glycogen concentrations were not affected.

Physiological relationships of the early posthatch performance of broilers to their embryo and eggshell characteristics

Relationships between physiological parameters of early posthatch chicks with their corresponding egg and embryo parameters were examined in progeny of young broiler breeders. Four hundred and 80 broiler hatching eggs that were obtained from a 29-wk-old Ross 308 breeder flock were incubated on 8 replicate tray levels of an incubator until hatch. Between 10.5 and 18.5 d of incubation, internal (T(emb)) and external (T(ext)) egg temperatures were recorded twice daily using temperature transponders. Beginning at 18.5 d, the eggs were individually monitored for hatch every 12 h. Average T(emb), T(ext), and average daily incubational egg weight loss (EWL) for the 10.5- to 18.5-d incubation period were used to calculate eggshell water vapor conductance (G(H2O)), specific G(H2O) (g(H2O); G(H2O) adjusted to 100 g of set egg weight basis), and a G(H2O) constant (K(H2O)) for each egg. Chicks were grown out for 10 d in pens of a single battery brooder. In each pen, on d 3 posthatch, carcasses, yolk sac, liver, and pipping muscle samples were collected from at least 2 chicks that hatched from eggs implanted with transponders for determination of their relative weights and moisture concentrations. Livers and pipping muscles were also analyzed for glucose, glycogen, fat, and protein concentrations. Yolk sac weight as a percentage of chick BW (YW) and its moisture concentration (YSM) were positively correlated with T(emb). Egg g(H2O) was positively correlated with chick carcass moisture concentration and its relative weight as a percentage of set egg weight, but it was negatively correlated with YW. The positive functional relationship between T(emb) and incubation length may be mediated via their common positive relationships to YSM. A negative correlation was observed between percentage EWL and relative BW on d 0 and 0.5 posthatch for chicks hatched from unimplanted eggs. The results suggest that a higher g(H2O) results in an increased metabolism of the broiler embryo, which subsequently increases growth and yolk sac absorption in broiler chicks through 3 d posthatch.

Comparative evaluation of air cell and eggshell temperature measurement methodologies used in broiler hatching eggs during late incubation

The current study was conducted to compare and contrast the uses of 2 devices (temperature transponder or infrared thermometer) and their locations (inner air cell membrane or outer eggshell surface) in Ross × Ross 708 broiler hatching eggs. The air cells of 14 embryonated and 10 nonembryonated eggs were implanted with temperature transponders on d 13.5 of incubation. Likewise, for these same eggs, eggshell surface temperature was detected with the use of transponders and an infrared thermometer. Temperatures were recorded every 12 h between 14.5 and 18 d of incubation, and graphs and corresponding regression values were used to track the temperatures over these time periods. The temperature readings using all methods in embryonated and nonembryonated eggs were positively correlated. In nonembryonated eggs, temperatures in the air cell and on the eggshell surface using transponders were higher than those on the eggshell surface using an infrared thermometer. Mean air cell temperature readings of embryonated eggs using transponders were higher than those of the eggshell, as determined with the use of transponders or an infrared thermometer. Furthermore, the differences in air cell temperature using transponders and eggshell temperature using an infrared thermometer in embryonated eggs increased with embryonic age. These readings confirmed increased embryo heat production during the incubational period examined. It was further concluded that when compared with actual embryo body temperatures determined in previous studies, the use of transponders in the air cells of broiler hatching eggs detected a higher and closer temperature than eggshell surface temperature. It is suggested that the air cell transponders in embryonated eggs circumvented the confounding effects of the thermal barrier properties of the eggshell and the flow of air across its surface.

Effects of in ovo injection of carbohydrates on somatic characteristics and liver nutrient profiles of broiler embryos and hatchlings

Effects of the in ovo injection of commercial diluent supplemented with dextrin or with dextrin in combination with various other carbohydrates on the somatic characteristics and liver nutrient profiles of Ross × Ross 708 broiler embryos and chicks were investigated. Results include information concerning the gluconeogenic energy status of the liver before and after hatch. Eggs containing live embryos were injected in the amnion on d 18 of incubation using an automated multiple-egg injector for the delivery of the following carbohydrates dissolved in 0.4 mL of commercial diluent: 1) 6.25% glucose and 18.75% dextrin; 2) 6.25% sucrose and 18.75% dextrin; 3) 6.25% maltose and 18.75% dextrin; and 4) 25% dextrin. Also, a noninjected control and a 0.4-mL diluent-injected control were included. Body weight relative to set egg weight on d 19 of incubation (E19) was increased by the injection of all carbohydrate solutions, and on the day of hatch was increased by the injection of diluent, sucrose and dextrin, and maltose and dextrin solutions. Hatchability of the fertilized eggs, residual yolk sac weight, and liver weight were not affected by any injection treatment; however, as compared with the 0.4 mL diluent-injected group, all of the supplementary carbohydrates, except for the glucose and dextrin combination group, increased liver glycogen and glucose concentrations on E19. Furthermore, all carbohydrates, except for the 25% dextrin treatment, decreased liver fat concentration on E19. From E19 to the day of hatch, liver glycogen concentrations dropped dramatically from an average of 3.2 to 0.6%. Despite treatment differences observed on E19 for liver glycogen, glucose, and fat concentrations, these differences were lost by the day of hatch. Nevertheless, liver glycogen and glucose concentrations were positively correlated on the day of hatch. In conclusion, the in ovo injection of various supplemental carbohydrates dissolved in 0.4 mL of commercial diluent altered the liver nutrient profile of Ross × Ross 708 broiler embryos before hatch. However, the subsequent pattern of energy utilization during the hatching process modified these effects.

Determination of embryonic temperature profiles and eggshell water vapor conductance constants in incubating Ross x Ross 708 broiler hatching eggs using temperature transponders

The comprehensive profiles of the internal and external temperatures of embryonated Ross × Ross 708 broiler hatching eggs during incubation were determined using temperature transponders, and eggshell water vapor conductance (G(H2O)), specific G(H2O) (g(H2O); G(H2O) adjusted to a 100 g set egg weight basis), and G(H2O) constants (K(H2O)) were calculated. On each of 8 replicate tray levels of an incubator, 2 nonembryonated and 4 embryonated eggs were each implanted with a transponder on d 10.5 of incubation for the determination of internal (air cell) temperatures of nonembryonated (T(nem)) and embryonated (T(emb)) eggs, respectively. In addition, 2 water-filled vials, each containing a transponder, were used on each tray level for the determination of the external microenvironment temperatures (T(ext)) of the embryonated and nonembryonated eggs. Between 10.5 and 18 d of incubation, incubator data logger temperatures were determined every 5 min; and incubator dry bulb temperature, T(ext), T(nem), T(emb), and the difference between T(emb) and T(nem) (T) were determined every 12 h. Over the days of incubation, regression coefficients for T(emb) and T were positive, whereas the regression coefficient for T(nem) was negative. There was a significant day of incubation × type of temperature measurement (T(ext), T(nem), and T(emb)) interaction for temperature. Between 13 and 18 d of incubation, mean values of T(emb) readings that were recorded every 12 h were consistently higher than those of T(ext) and T(nem), indicating the importance of air cell transponder implantation for the efficient estimation of broiler embryo temperature. Furthermore, mean values of the percentage of daily incubational egg weight loss, G(H2O), g(H2O), and K(H2O) of the embryonated eggs were 0.54 ± 0.019%, 14.4 ± 0.56 mg of H₂O/d per Torr, 25.0 ± 0.96 mg of H₂O/d per Torr per 100 g, and 5.20 ± 0.205, respectively. The results suggest that transponders may be implanted in the air cells of broiler hatching eggs to detect incubational variations in T(emb) and to subsequently calculate G(H2O), g(H2O), and K(H2O).

Effects of in ovo injection of carbohydrates on embryonic metabolism, hatchability, and subsequent somatic characteristics of broiler hatchlings

The effects of the in ovo injection of different carbohydrate solutions on the internal egg temperature (IT), hatchability, and time of hatch of embryonated Ross × Ross 708 broiler hatching eggs were determined. In addition, the BW, liver weight, yolk sac weight (YSW), and yolk-free BW (YFBW) of the embryos on d 19.5 of incubation and of the chicks on day of hatch were determined. Eggs containing live embryos were injected in the amnion on d 18.5 of incubation using an automated multiple-egg injector. Solution injections delivered 1.2 mL of physiological saline (0.85%) alone or with a supplemental carbohydrate. The following supplemental carbohydrates were separately dissolved in saline at a concentration of 0.3 g/mL: glucose, fructose, sucrose, maltose, and dextrin. Temperature transponders were implanted in the air cells of embryonated and nonembryonated eggs after in ovo injection for the detection of IT at 6, 14, and 22 h after injection. The IT of embryonated eggs was significantly greater than that of nonembryonated eggs at all 3 times after the treatment period. Eggs that were injected with saline with or without supplemental carbohydrates experienced a reduction in IT when compared with control eggs whose shells were perforated without solution delivery, and the decrease in IT was associated with a delay in hatch time. Liver weight was negatively related to YSW and positively related to YFBW, and YSW was negatively related to YFBW. Although the saline and carbohydrate solution injections increased chick BW compared with noninjected controls, chick YFBW was decreased in the maltose- and sucrose-injected groups. In conclusion, the injection of 1.2 mL of saline with or without supplemental carbohydrates lowered embryonic metabolism, as reflected by a lower IT and a delay in time of hatch. However, effects of the different carbohydrate solutions on yolk absorption and tissue deposition in yolk-free embryos varied. These results suggest that lower volumes for solutions containing maltose, sucrose, or fructose should be considered for in ovo injection.

Effects of commercial in ovo injection of carbohydrates on broiler embryogenesis

The effects of in ovo injection of different carbohydrate solutions on hatchability of fertilized eggs (HF), rate of hatch, BW, body moisture, yolk sac weight, and yolk sac moisture of Ross × 708 broiler chicks, hatched from eggs laid by a 34-wk-old breeder flock, were investigated. Eggs containing live embryos were injected, using an automated multiple-egg injector, in the amnion on d 18.5 of incubation with 0.1, 0.4, 0.7, or 1.0 mL of commercial diluent or a carbohydrate dissolved in diluent. The commercial diluent containing 0.25 g/mL of one of the following carbohydrates was injected into eggs: glucose, fructose, sucrose, maltose, or dextrin. The results showed that no carbohydrate type or solution volume affected rate of hatch. Absolute and proportional BW on day of hatch were positively related to injection volume (P < 0.001). However, HF was negatively related to injection volume (P < 0.001). To realize an HF of 90%, the injection volume could not exceed 0.4 mL for fructose or sucrose and could not exceed 0.7 mL for glucose, maltose, or dextrin. Yolk-free BW was negatively related to injection volume of fructose and sucrose (P < 0.004), but was not related to injection volume of diluent, glucose, maltose, and dextrin. Conversely, absolute and proportional yolk sac weights were positively related to injection volume of fructose, sucrose, and dextrin (P < 0.01), but were also not significantly related to injection volume of diluent, glucose, and maltose. Yolk sac moisture was positively related to injection volume for all injectables, including the diluent (P < 0.03). However, body moisture and yolk-free body moisture were not related to injection type or volume. In conclusion, the use of carbohydrates added to a commercial diluent for the in ovo injection of broiler hatching eggs requires the use of appropriate volumes to promote growth and nutrient utilization without adversely affecting HF.

[Early stage diagnosis of endometrial cancer based on near infrared spectroscopy and support vector machine]

Near-infrared spectroscopy combined with chemometrics methods for diagnosis of cancer has been reported in literatures. In our study, the NIR spectra of 77 specimens of different physiological stages of endometrium were collected. Spectral data were pretreated firstly by multiplicative scatter correction (MSC), orthogonal signal correction (OSC), and both of them, respectively, and then by SG smoothing. Latin partition method was used to select 3/4 samples as a training set, and the other 1/4 samples for test set. Support vector machine (SVM) model was built for classification, and the classification results was compared with that of partial least squares (PLS) model based on the same pretreatment methods. Samples of malignant, hyperplasia and normal endometrium were classified better by SVM (classification accuracy was 92%) than PLS (classification accuracy was 90%). The results suggested that classification accuracy was affected by pretreatment methods and models. SVM combined with endometrial tissue near infrared spectroscopy is expected to develop into a new approach to tumor diagnosis.

Chest wall reconstruction in a patient with sternal fibrous dysplasia

A patient with sternal fibrous dysplasia was treated via subtotal sternectomy using a sandwich titanium micromesh and polypropylene mesh to repair the chest wall defect. Pectoralis muscle flaps were created to cover the prosthesis. The patient had a normal postoperative course with good stability and postoperative cosmesis.

Brain death disrupts structure and function of pig liver

OBJECTIVE

To observe the effects of brain death on hepatic structure and function in pigs and to assess the role of nuclear factor kappaB (NF-kappaB).

MATERIALS AND METHODS

Twelve healthy pigs were randomly allocated to 2 groups of 6 each: a control group with Foley balloon catheter placement intracalvarium only, and a group with brain death established for 24 hours. Serum and hepatic tissue were obtained at 6, 12, and 24 hours after initial confirmation of brain death. Aspartate aminotransferase and alanine aminotransferase concentrations were determined using automated biochemistry analysis. Interleukin-1beta was determined using an enzyme-linked immunosorbent assay. The NF-kappaB messenger RNA was determined using real-time polymerase chain reaction, and NF-kappaB p65 using immunohistochemistry.

RESULTS

Concentrations of aspartate aminotransferase, alanine aminotransferase, and interleukin-1beta in serum, and NF-kappaB messenger RNA and NF-kappaB p65 in hepatic tissue were higher in the brain-dead group compared with the control group, and all increased over time (P<.05).

CONCLUSION

The NF-kappaB activated by brain death promotes synthesis and release of inflammatory mediators, resulting in hepatic dysfunction.

Increased lipolysis in adipose tissues is associated with elevation of systemic free fatty acids and insulin resistance in perilipin null mice

Elevated plasma levels of free fatty acids (FFAs) are thought to restrict glucose utilization and induce insulin resistance. Plasma FFA concentrations are primarily governed by lipolysis in adipocytes. Perilipin surrounds the lipid droplet in adipocytes and has a dual role in lipolysis regulation. Perilipin null mice studied by two independent laboratories exhibited similar phenotypes of reduced adipose mass and resistance to diet-induced obesity, but have inconsistent metabolic parameters such as plasma levels of FFA, glucose, and insulin. This discrepancy may be due to differences in genetic background, generation, and nutritional status of the animals examined. In this study, we examined the major metabolic parameters in 129/SvEv perilipin null mice fasted for 4 h and observed increased plasma concentrations of FFA, glycerol, glucose, and insulin. An increase in the score for the homeostasis model assessment of insulin resistance index confirmed the insulin resistance in perilipin null mice, which may be attributed to the plasma FFA elevation. Basal lipolysis was increased in adipose tissues or primary adipocytes isolated from perilipin null mice with increased mass and activity of hormone-sensitive lipase and adipose triglyceride lipase. The increased lipolytic action may accelerate FFA efflux from the adipose tissues to the bloodstream, thereby accounting for systemic FFA elevation and, hence, insulin resistance in perilipin null mice.

Introduction of a rice blight resistance gene,Xa21, into five Chinese rice varieties through an Agrobacterium-mediated system

A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium- mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3: 1 ratio in the selfed T(1) generation when one copy of the gene was integrated in the transformants. Inoculation tests displayed that transgenic T(0) plants and Xa21 PCR-positive T(1) plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

[Comparative Proteomic Analysis of Human Lung Adenocarcinoma Cisplatin-resistant Cell Strain A549/CDDP.]

BACKGROUND

Chemotherapy plays an important role in the comprehensive therapy of lung cancer. However, the drug-resistance often causes the failure of the chemotherapy. The aim of this study is to identify differently expressed protein before and after cisplatin resistance of human lung adenocarcinoma cell A549 by proteomic analysis.

METHODS

Cisplatin-resistant cell strain A549/CDDP was established by combining gradually increasing concentration of cisplatin with large dosage impact. Comparative proteomic analysis of A549 and A549/CDDP were carried out by means of two-dimensional gel electrophoresis. The differentially expressed proteins were detected and identified by MALDI-TOF mass spectrometry.

RESULTS

Eighty-two differentially expressed proteins were screened by analysis the electrophoretic maps of A549 and A549/CDDP. Six differential proteins were analyzed by peptide mass fingerprinting. Glucose regulating protein 75, ribosomal protein S4, mitochondrial ATP synthase F1 complex beta subunit and immunoglobulin heavy chain variable region were identified. All four differentially expressed proteins were over-expressed in A549/CDDP, whereas low-expressed or no-expressed in A549.

CONCLUSIONS

These differentially expressed proteins give some clues to elucidate the mechanism of lung cancer cell resistant of cisplatin, providing the basis of searching for potential target of chemotherapy of lung cancer.

[Observation on therapeutic effect of treatment for children with cerebral palsy by acupuncture]

OBJECTIVE

To evaluate the clinical therapeutic effect of acupuncture treatment of children cerebral palsy with gaining in wisdom and activating channels method.

METHODS

Sixty cases were randomly divided into a gaining in wisdom and activating channels group, a JIN's 3-needling group and a routine acupuncture group, 20 cases in each group. The gaining in wisdom and activating channels group was treated with point group of the head selected as main points combined with Dazhui (GV 14), Jinsuo (GV 8), Mingmen (GV 4), Yaoyangguan (GV 3), Hegu (LI 4), Neiguan (PC 6), Sanyinjiao (SP 6), etc., the JIN's 3-needling group was treated with Four-shen needling and Dazhui (GV 14), Shenzhu (GV 12), Fengfu (GV 16), etc. were selected as main acupoints in the routine acupuncture group. Comprehensive Function Evaluation for Disabled Children was used for assessment of comprehensive function of disabled children.

RESULTS

The total effective rate of 90.0% in both the gaining in wisdom and activating channels group and the JIN's 3-needling group, with no significant difference between the two groups (P > 0.05), were better than that of 60.0% in the routine acupuncture group (P < 0.05).

CONCLUSION

Acupuncture treatment with gaining in wisdom and activating channels method can significantly improve the comprehensive function of disabled children with more obvious therapeutic effects.

Brain death affects the hepatic immunogenicity of pigs

OBJECTIVE

The purpose of this study was to observe how the brain-death state affects the hepatic immunogenicity of pigs.

MATERIALS AND METHODS

Twelve healthy ChangBai pigs were allocated randomly to 2 groups: control group (n = 6) with Foley catheter balloon placed intracalvarium for 24 hours only versus brain-death group (n = 6) with brain death for 24 hours. The serum and hepatic tissues were obtained at 6, 12, and 24 hours after the initial confirmation of brain death. Tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were determined by enzyme-linked immunosorbent assay (ELISA). The major histocompatibility complex class II (MHC-II) was determined by immunohistochemistry, and the intercellular adhesion molecule-1 (ICAM-1) mRNA and monocyte chemotactic protein-1 (MCP-1) mRNA by real-time polymerase chain reaction (PCR).

RESULTS

The serum TNF-alpha and IL-6, MHC-II, ICAM-1 mRNA, and MCP-1 mRNA in hepatic tissues in the brain-death group were higher than in the control group; they all increased with time.

CONCLUSION

Brain death increased liver immunogenicity, which may increase the immune lesion and rejection after transplantation.

Analysis and location of a rice BAC clone containing telomeric DNA sequences

BAC2, a rice BAC clone containing (TTTAGGG)(n) homologous sequences, was analyzed by Southern hybridization and DNA sequencing of its subclones. It was disclosed that there were many tandem repeated satellite DNA sequences, called TA352, as well as simple tandem repeats consisting of TTTAGGG or its variant within the BAC2 insert. A 0. 8 kb (TTTAGGG)(n)-containing fragment in BAC2 was mapped in the telomere regions of at least 5 pairs of rice chromosomes by using fluorescencein situ hybridization (FISH). By RFLP analysis of low copy sequences the BAC2 clone was localized in one terminal region of chromosome 6. All the results strongly suggest that the telomeric DNA sequences of rice are TTTAGGG or its variant, and the linked satellite DNA TA352 sequences belong to telomere-associated sequences.

The effect of male and female supplementation of L-carnitine on reproductive traits of white leghorns

Previous work in our laboratory showed that including 125 ppm of l-carnitine in the diets of roosters increased sperm concentration. The objective of this experiment was to determine whether reproductive efficiency could be improved by feeding l-carnitine to both parents over that of feeding l-carnitine to only the male or female. Diets formulated to contain 0 or 125 ppm of l-carnitine were fed to male and female birds from hatch until 37 wk of age. Eighty-four roosters were used, with the semen of 2 roosters constituting an experimental unit. Pools of semen from either l-carnitine-supplemented or control roosters were artificially inseminated into each of 288 hens with 23.5 muL of semen at weekly intervals, in a 2 x 2 factorial arrangement, resulting in a mean insemination dose of 1.2 and 1.1 x 10(8) sperm/hen for l-carnitine and control hens, respectively. Dietary l-carnitine, as compared with the control diet, increased egg yolk l-carnitine concentration (P = 0.001), decreased hatchling yolk sac weights (P = 0.0001), decreased yolk sac lipid content at hatch (P = 0.01), and culminated in compositional changes of yolk fatty acids, but it did not affect hatch rate, egg production, and egg traits. Although supplementing diets with l-carnitine improved sperm concentration, it did not result in a subsequent improvement in hatch rate, most likely because of the high numbers of sperm that were inseminated artificially in both the control and l-carnitine-supplemented hens. The higher concentrations of l-carnitine in the yolk of hatching eggs obtained from hens consuming l-carnitine as compared with controls may have encouraged the utilization of fat by developing embryos, as indicated by the decreased hatchling yolk sac weights and yolk sac lipid content, perhaps leading to the selective utilization of linoleic (C18:2n-6) and alpha-linolenic (C18:3n-3) acids for growth and development over myristic (C14:0) and oleic (C18:1n-9) acids.

Autologous fibrin sealant reduces the incidence of prolonged air leak and duration of chest tube drainage after lung volume reduction surgery: a prospective randomized blinded study

OBJECTIVE

Prolonged air leak is reported in up to 50% of patients after lung volume reduction surgery. The effect of an autologous fibrin sealant on the intensity and duration of air leak and on the time to chest drain removal after lung volume reduction surgery was investigated in a randomized prospective clinical trial.

METHODS

Twenty-five patients underwent bilateral thoracoscopic lung volume reduction surgery. In each patient, an autologous fibrin sealant was applied along the staple lines on one side, whereas no additional measure was taken on the other side. Randomization of treatment was performed at the end of the resection on the first side. Air leak was assessed semiquantitatively by use of a severity score (0 = no leak; 4 = continuous severe leak) by two investigators blinded to the treatment.

RESULT

Mean value of the total severity scores for the first 48 hours postoperative was significantly lower in the treated group (4.7 +/- 7.7) than in the control group (16.0 +/- 10.1) (P < .001), independently of the length of the resection. Prolonged air leak and mean duration of drainage were also significantly reduced after application of the sealant (4.5% and 2.8 +/- 1.9 days versus 31.8% and 5.9 +/- 2.9 days) (P = .03 and P < .001).

CONCLUSIONS

Autologous fibrin sealant for reinforcement of the staple lines after lung volume reduction surgery significantly reduces prolonged air leak and duration of chest tube drainage.

The effect of in ovo injection of L-carnitine on hatchability of white leghorns

Two experiments were conducted to determine if L-carnitine injected in ovo affected hatchability. Eggs of experiment 1 were injected with sterilized saline (0.85%) or L-carnitine (0.25, 0.50, 1.00, or 2.00 micromol dissolved in saline). An additional group of eggs served as noninjected controls. Hatchabilities were unaffected by treatment (94% for noninjected controls; 94% for saline injected eggs; and 87, 87, 88, and 88% for eggs injected with 0.25, 0.50, 1.00, or 2.00 micromol of L-carnitine, respectively; SEM = 1). Yolk sac weights retrieved from hatchings that were subjected to 0, 0.25, or 0.50 micromol of L-carnitine as embryos through in ovo injection were 3.9, 3.8, and 3.6 g, respectively (SEM = 0.1, P = 0.71). Eggs used in experiment 2 were injected with a wider dosimetry of l-carnitine. Fertile eggs were injected with sterilized saline (0.85%) or L-carnitine (0.05, 0.5, 5, or 10 micromol dissolved in saline). An additional group of eggs served as noninjected controls. Chick BW and % hatch were unaffected by treatment (76% for noninjected controls; 74% for saline injected eggs; and 77, 77, 68, and 76% for eggs injected with 0.05, 0.5, 5, or 10 micromol of L-carnitine, respectively; SEM = 3). In ovo injection of L-carnitine into fertile chicken eggs at 17 or 18 d of incubation did not affect hatchability, yolk sac weight, or BW.

Simplified rat lung transplantation by using a modified cuff technique

Mizuta's cuff technique in rat lung transplantation (LT) model has some disadvantages, such as twisting of blood vessels or bronchus and being time-consuming, which complicate procedures for anastomosis. This study was performed to investigate the advantage of using a simplified cuff technique in LT. The anastomosis time was compared in two groups. In group I, Mizuta'scuff technique was performed in 50 rat orthotopic left lung transplants. In group II, a simple modified cuff technique was performed in 48 rat orthotopic left lung transplants. The successful rate of the new technique for anastomosis was 100%. No twist of vessels or bronchus and no bleeding or air leakage were observed in group II. The anastomosis time of group II was significantly less than for group I (11.2 +/- 2.1 min vs. 18.1 +/- 3.6 min, mean +/- SD, p < .01). This simple modified cuff technique led to less anastomosis time and avoided potential complications induced by the cuff-tail technique. It has been verified to be a safe, simple, and reproducible technique that can provide us with a more precise assessment in the rat LT model.

Acute allograft rejection and immunosuppression: influence on endogenous melatonin secretion

Melatonin displays a dose-dependent immunoregulatory effect in vitro and in vivo. Exogenous high-dose melatonin therapy exerted an immunosuppressive effect, abrogating acute rejection (AR), significantly prolonging transplant survival. Endogenous melatonin secretion, in response to heterotopic rat cardiac allograft transplantation (Tx), was investigated during the AR response and under standardized immunosuppressive maintenance therapy with cyclosporin A (CsA) and rapamycin (RPM). Recipients of syngeneic transplants, and recipients of allogeneic grafts, either untreated or receiving immunosuppressive therapy constituted the experimental groups. Endogenous circadian melatonin levels were measured at 07:00, 19:00, and 24:00 hr, using a novel radioimmunoassay (RIA) procedure, under standardized 12-hr-light/dark-conditions (light off: 19:00 hr; light on: 07:00 hr), before and after Tx. Neither the operative trauma, nor the challenge with a perfused allograft or the AR response influenced endogenous melatonin peak secretion. Immunosuppressive therapy with CsA led to a significant increase in peak secretion, measured for days 7 (212 +/- 40.7 pg/mL; P < 0.05), 14 (255 +/- 13.9 pg/mL; P < 0.001), and 21 (219 +/- 34 pg/mL; P < 0.01) after Tx, as compared with naïve animals (155 +/- 25.8 pg/mL). In contrast, treatment with RPM significantly decreased the melatonin peak post-Tx up to day 7 (87 +/- 25.2 pg/mL; P < 0.001), compared with naïve animals (155 +/- 25.8 pg/mL). These findings imply a robust nature of the endogenous circadian melatonin secretion kinetics, even against the background of profound allogeneic stimuli. Immunosuppressive maintenance therapy with CsA and RPM modulated early melatonin secretion, indicating a specific secondary action of these drugs. Further studies are necessary to disclose the long-term effect of immunosuppressive therapy on circadian melatonin secretion in transplant recipients.

The Effect of Dietary l-Carnitine on Semen Traits of White Leghorns

A previous study conducted in our laboratory showed that feeding 500 ppm of dietary L-carnitine to young and aging White Leghorns for 5 wk improved sperm concentration and reduced sperm lipid peroxidation during the last half of supplementation. The current study examined the effect of feeding dosimetric as well as lower levels of L-carnitine for longer durations on semen traits of White Leghorns. In experiments 1 and 2, White Leghorns consumed diets supplemented with 0, 125, 250, or 500 mg of L-carnitine/kg of feed. For experiment 1, an 8-wk trial was conducted with 48 White Leghorns from 46 to 54 wk of age. For experiment 2, a 17-wk trial was conducted with 96 White Leghorn roosters from 46 to 63 wk of age. For experiment 3, 84 roosters were provided for ad libitum consumption a diet formulated to contain 0 or 125 ppm of L-carnitine beginning at hatch until 37 wk of age. Long-term consumption of 125 ppm of L-carnitine beginning at hatch was the only dietary treatment that sustained a persistent increase in sperm concentration. These results suggest that L-carnitine's antioxidant influence on sperm production begins before the onset of sexual maturity.

N-acetylcysteine attenuates lung ischemia-reperfusion injury after lung transplantation

BACKGROUND

Early acute graft dysfunction continues to be a problem after lung transplantation and results in significant postoperative morbidity and mortality. This study assessed the protective effect of N-acetylcysteine (NAC) on posttransplant lung ischemia-reperfusion injury.

METHODS

Rat single-lung transplantation was performed in two experimental groups (n = 5) after 18 hours of cold (4 degrees C) ischemia. Group I was the ischemic control (IC) group. In group II (NAC), donor and recipient animals were treated with an intraperitoneal injection of 150 mg/kg NAC 15 minutes before harvest, and recipient animals were treated again before reperfusion. After 2 hours of reperfusion, oxygenation was measured. Lung tissue was assessed for lipid peroxidation, neutrophil infiltration, and reduced glutathione level. Peak airway pressure was recorded throughout the reperfusion period.

RESULTS

Rats treated with NAC showed significantly better oxygenation (184.5 +/- 83.3 mm Hg versus 67.3 +/- 16.4 mm Hg, p = 0.016) and reduced lipid peroxidation (7.34 +/- 1.9 micromol/g versus 17.46 +/- 10.6 micromol/g, p = 0.016). Lung tissue reduced glutathione levels were 6.8 +/- 0.9 microM in the IC group and 20.6 +/- 2.4 microM in the NAC group (p = 0.004). Peak airway pressure at the end of the reperfusion period was 14.4 +/- 1.6 cm H2O in the NAC group, and 19.2 +/- 2.2 cm H2O in the IC group (p = 0.008). Myeloperoxidase activity and the ratio of wet-to-dry weight did not differ between the groups.

CONCLUSIONS

In this model, exogenously administered NAC effectively protected the lungs from reperfusion injury after prolonged ischemia.

Intragraft DPP IV Inhibition Attenuates Post-transplant Pulmonary Ischemia/Reperfusion Injury After Extended Ischemia

BACKGROUND

CD26/DPP IV is a T-cell-membrane protein that cleaves dipeptides from extracellular peptides. Inhibition of its enzymatic activity using Pro-Pro-diphenylphosphonate derivatives has been shown to abrogate acute and accelerated rejection in models of cardiac and pulmonary allotransplantation. Here we investigated the effects of enzymatic DPP IV inhibition on ischemia/reperfusion (I/R) injury after extended ischemia before pulmonary transplantation.

METHODS

A syngeneic rat orthotopic left-lung transplantation model was used. Group I donor lungs (controls) were flushed and preserved in Perfadex for 18 hours at 4 degrees C and then transplanted and reperfused for 2 hours. Group II grafts were perfused with and stored in Perfadex + 25 micromol/liter AB192 [bis(4-acetamidophenyl) 1-(S)-prolylpyrrolidine-2(R,S)-phosphonate]. Group III lungs were perfused with Perfadex + AB192, and stored in Perfadex. After 2-hour reperfusion, oxygenation, peak airway pressure (PawP), graft wet/dry (W/D) weight ratio, myeloperoxidase activity, thiobarbituric acid-reactive substances, graft specific DPP IV enzymatic activities and histomorphology were analyzed.

RESULTS

AB192 perfusion significantly reduced DPP IV intragraft enzymatic activity in Groups II and III. Compared with controls, transplants from Groups II and III showed significantly improved oxygenation capacity, PawP and W/D weight ratio, with lower intragraft lipid peroxidation; and preserved histologic structure.

CONCLUSIONS

Targeting intragraft DPP IV enzymatic activity attenuated post-transplantation I/R injury and preserved early graft function after extended ischemia.

Ischemia/Reperfusion Injury: The Role of CD26/Dipeptidyl-Peptidase-IV-Inhibition in Lung Transplantation

CD26/Dipeptidyl peptidase (DPP) IV is an integral membrane protein of lymphocytes that modulates the activities of chemokines, interleukins, and neuropeptides. We investigated the effect of enzymatic DPP IV inhibition on ischemia/reperfusion injury after extended ischemia prior to transplantation.

MATERIALS AND METHODS

We used a syngeneic rat (Lewis) orthotopic left lung transplantation model. In the control group (group I), donor lungs were flushed and preserved in Perfadex for 18 hours at 4 degrees C, then transplanted and reperfused for 2 hours. Group II donor lungs were perfused with and stored in Perfadex +25mol/L AB192 (bis(4-acetamidophenyl) 1-(S)-prolylpyrrolidine-2(R,S)-phosphonate), a small molecular weight DPP IV inhibitor. After 2-hour reperfusion, we measured blood gas, peak airway pressure, and thiobarbituric acid reactive substances.

RESULTS

Grafts from group II versus group I showed a significantly increased oxygenation capacity (II: 298.4 +/- 87.6 mm Hg vs 120.9 +/- 48.0, P < .01), lower peak airway pressure (11.8 +/- 0.9 mm Hg vs 16.0 +/- 1.4, P < .01), and less lipid peroxidation (9.3 +/- 2.0 micromol/L vs 13.8 +/- 1.8, P < .01).

CONCLUSION

Inhibition of intragraft DPP IV enzymatic activity significantly reduced ischemia/reperfusion-associated pulmonary injury, allowing for successful transplantation after 18 hours of ischemia.

Sildenafil extends survival and graft function in a large animal lung transplantation model☆

OBJECTIVE

Restoring intracellular cGMP and inducing NO-synthesis attenuates ischemia-associated early pulmonary allograft dysfunction. Phosphodiesterase-5 (PDE), predominantly expressed in lung tissue, plays a pivotal role in modulating the cGMP/NO-synthase pathway in endothelial and epithelial cells. In this study, we evaluate the effect of employing sildenafil (Viagra), a specific inhibitor of PDE-5, to counteract ischemia/reperfusion (I/R) injury in a single lung transplantation model of extended ischemia.

METHODS

Donor animals (weight matched outbred pigs, 28-35 kg) in the treatment group (I) (n=5) were injected with 0.7 mg sildenafil/kg into the pulmonary artery (PA) prior to inflow occlusion. For perfusion, Perfadex, containing 0.7 mg sildenafil/l was used, and the graft stored at 1 degrees C in the perfusion solution. After 24h ischemia, unilateral left lung transplantation was performed. Starting at reperfusion, group I received continuous sildenafil (0.7 mg sildenafil/kg), over 6h. Except for the sildenafil application, the control group (II) (n=4) was treated identically (PGE1 was injected into the PA). One hour after reperfusion, the right main bronchus (MB) and right PA were occluded. Over the next 5h, cardiopulmonary parameters (systemic atrial, PA, central venous, left atrial pressure, pCO(2), pO(2)) were measured, including extravascular lung water (EVLW). Thiobarbituric acid-reactive substance assay (TBARS) and myeloperoxidase (MPO) analysis from lung tissue were run.

RESULTS

All recipients of group I survived the 6-h reperfusion period; in contrast, all control animals died within 1-2h after occlusion of the right side. In comparison to a marked rise in pulmonary vascular resistance (PVR) in group II (>1000 dynescm(-5)), PVR in group I remained stable, moderately elevated from baseline (baseline: 150-180 dynescm(-5) vs endpoint: 1000 dynescm(-5)). EVLW in group I did not increase during reperfusion (baseline: 6.75+/-1.4 mg/kg vs endpoint: 6.7+/-1.0mg/kg), in contrast to group II, where pulmonary edema at 2-h reperfusion preceded terminal graft failure (group I: 9.7+/-0.1mg/kg vs group II: 6.48+/-1.8 mg/kg). Tissue reactive free radicals at endpoint measurement in group I did not differ significantly from native tissue. Yet, when compared to specimen taken from group II at time of terminal graft failure, a significant increase in free radicals was noted (group I: 13.8+/-1.6 pmol/g vs group II: 18.5+/-3.0 pmol/g, p<0.05).

CONCLUSION

Sildenafil treatment prevents terminal early graft failure, allowing lung transplantation after 24-h ischemia time. Reperfusion edema was strikingly diminished, preserving pulmonary structural and functional integrity while prolonging graft ischemia time. Employing the established PDE-5 inhibitor sildenafil during lung perfusion, storage, and implantation, ischemic tolerance may be extended and early graft function improved.

[In vitro experiment of inhibiting cell proliferation on human esophageal squamous cell cancer T. Tn cell line by proliferating cell nuclear antigen antisense oligodeoxynucleotide]

BACKGROUND & OBJECTIVES

The high expression of proliferation cell nuclear antigen were found in the patients with esophageal carcinoma in poor prognosis. The aim of this study was to investigate the effect in vitro of antisense oligodeoxynucleotide (ASODN) of PCNA on its gene expression and cell proliferation in human esophageal squamous cell cancer T. Tn cell line.

METHODS

Phosphorothioate PCNA ASODN and sense oligodeoxynucleotide (SODN) were synthesized and transfected to T. Tn cells mediated by dosper liposomal. Their effects on cell proliferation were examined by MTT method, 3H-TdR method, immunohistochemical study, and flow cytometer (FCM).

RESULTS

PCNA ASODN could significantly inhibit the growth of T. Tn cell lines. The SODN and control lipsome showed no such effect. The inhibition peaked at 24 hour after transfection, the inhibition rate reached 63.3% at 0.2 mumol/L by MTT method, the inhibition effect was dose-dependent. ASODN could downregulate the expression levels of PCNA protein. And PCNA ASODN transfection could inhibit the transition period of G0/G1 phase to S phase.

CONCLUSIONS

The data suggested that ASODN could specific inhibit the expression of PCNA protein and regulate cell cycle and cell proliferation in T. Tn cells and antisense therapy could be an useful method to improve prognosis in ESCC.

[Expression of telomerase reverse transcriptase and its relationship with tumor suppressor gene p53 in HCC]

OBJECTIVE

To explore the expression of human telomerase reverse transcriptase (HTERT) and its relationship with tumor suppressor gene p53.

METHODS

RNA-RNA in situ hybridization (ISH) technique was applied to localize the expression of HTERT mRNA and immunohistochemistry (IHC) was used to observe the p53 protein expression in 34 specimens of HCC and their corresponding non-cancerous tissues. Both the significance of HTERT mRNA expression in the different histopathologic characters and its relationship with p53 protein were investigated.

RESULTS

HTERT was detected in tumor tissue in 30 of 34 cases (88.2%), and all the 6 cases of small cancer (diameter<3cm) were positive. The positive rate of HTERT mRNA was higher in the tumor tissues with low-differentiation, extra- or intra-hepatic metastasis, uncompleted fibrotic capsule and/or the non-cancerous tissue with chronic active lesions or positive HBsAg. Intensive signal was seen both in the HCC cells along the front of invasive area and in a few non-cancerous liver cells with dysplasia. Of all 34 HCC, p53 protein was presented in 25 cases. There was a correlation between the expression of HTERT mRNA and of p53 protein. The coincidence rate of the expression (HTERT+/p53+ and HTERT-/p53-) was 79.4%. More intensity of HTERT signal could be seen in the cases of positive p53. HTERT mRNA was not found in normal liver tissues.

CONCLUSIONS

High expression of HTERT mRNA is proved in most cases of HCCs. HTERT expression may relate to the pathogenesis and the invasion of HCC. p53 may play a role in regulating the expression of HTERT.

NBS-LRR resistance gene homologues in rice

Twenty three DNA fragments with a size of about 520 bp have been cloned from rice genome by PCR amplification using primers designed according to the conserved region of most plant resistance (R) genes which have Nucleotide Binding Site (NBS) and Leucine-Rich Repeat (LRR) domains. Homologous comparison showed that these fragments contained typical motifs of the NBS-LRR resistance gene class, kinase 1a, kinase 2a, kinase 3a and domain 2. Thus they were named R gene homologous sequences (RS). These RS were divided into 4 groups by clustering analysis and mapped onto chromosomes 1, 3, 4, 7, 8, 9, 10 and 11, respectively, by genetic mapping. Ten RS were located in the chromosomal intervals where known R genes had been mapped. Further RFLP analysis of an RS, RS13, near the bacterial blight resistance geneXa4 locus on chromosome 11 among near isogenic lines and pyramiding lines ofXa4 showed that RS13 was possibly amplified from the gene family ofXa4.

[Effects of hypoxia on expression and activity of matrix metalloproteinase-2 in hepatic stellate cell]

OBJECTIVE

To study the effect of hypoxia on the expression and activity of matrix metalloproteinase-2 (MMP-2) in the hepatic stellate cell (HSC).

METHODS

The expression of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) in cultured rat HSC was detected by immunocytochemistry (ICC). The relative amount of MMP-2 and TIMP-2 in the culture supernatant was assayed by ELISA and the activity of MMP-2 in supernatant was examined by zymography.

RESULTS

The expression of MMP-2 was enhanced in hypoxia group as compared with that in control one (t' 3.4685, P<0.05 ), while the expression of TIMP-2 was decreased (t'=2.5673, P<0.05). The activity of MMP-2 was lower in hypoxia group than in control one (t'=4.270, P<0.01). Comparing the varied duration of hypoxia, the relative amount of MMP-2 protein was the highest in 6 h group (6h vs 12h, t=4. 0945, P<0.001; 6h vs 24h, t=2.4652, P<0.025), with a contrary curve in TIMP-2.

CONCLUSION

Hypoxia promotes the expression of MMP-2 and inhibits the expression of TIMP-2 in HSC. It is more notable at early stage of hypoxia.

Structure-activity studies including a Psi(CH(2)-NH) scan of peptide YY (PYY) active site, PYY(22-36), for interaction with rat intestinal PYY receptors: development of analogues with potent in vivo activity in the intestine

Peptide YY (PYY) is a gut hormone that inhibits secretion and promotes absorption and growth in the intestinal epithelium. We have performed structure-activity studies with the active site, N-alpha-Ac-PYY(22-36)-NH(2), for interaction with intestinal PYY receptors. Investigation of aromatic substitutions at position 27 resulted in analogues that exhibited potent in vitro antisecretory potencies with N-alpha-Ac-[Trp(27)]PYY(22-36)-NH(2) exhibiting even greater potency than intact PYY. In vivo studies in dogs revealed that this analogue also promoted intestinal absorption of water and electrolytes during continuous intravenous and intraluminal infusion. Investigations carried out to identify features that would enhance stability revealed that incorporation of Trp(30) increased affinity for PYY receptors. A "CH(2)-NH" scan revealed that incorporation of reduced bonds at position 28-29 or 35-36 imparted greater receptor affinity. In general, disubstituted analogues designed based on the results of single substitutions exhibited good receptor affinity with N-alpha-Ac-[Trp(27),CH(2)-NH(35-36)]PYY(22-36)-NH(2) having the greatest affinity (IC(50) = 0.28 nM). Conservative multiple substitutions with Nle-->Leu and Nva-->Val also imparted good affinity. An analogue designed to encompass most of the favored substitutions, N-alpha-Ac-[Nle(24,28),Trp(30),Nva(31), CH(2)-NH(35-36)]PYY(22-36)-NH(2), exhibited a proabsorptive effect in dogs comparable to, but longer lasting than, that of intact hormone. Selected analogues also exhibited good antisecretory potencies in rats with N-alpha-Ac-[Trp(30)]PYY(22-36)-NH(2) being even more potent than PYY. However, the potencies did not correlate well with the PYY receptor affinity or the proabsorptive potencies in dogs. These differences could be due to species effects and/or the involvement of multiple receptors and neuronal elements in controlling the in vivo activity of PYY compounds. PYY(22-36) analogues exhibited good affinity for neuronal Y2 receptors but poor affinity for Y1 receptors. Also, crucial analogues in this series hardly bound to Y4 and Y5 receptors. In summary, we have developed PYY(22-36) analogues which, via interacting with intestinal PYY receptors, promoted potent and long-lasting proabsorptive and antisecretory effects in in vivo models. These compounds or analogues based on them may have useful clinical application in treating malabsorptive disorders observed under a variety of conditions.

Repression of RNA polymerase I transcription by the tumor suppressor p53

The tumor suppressor protein p53 is frequently inactivated in tumors. It functions as a transcriptional activator as well as a repressor for a number of viral and cellular promoters transcribed by RNA polymerase II (Pol II) and by RNA Pol III. Moreover, it appears that p53 also suppresses RNA Pol I transcription. In this study, we examined the molecular mechanism of Pol I transcriptional inhibition by p53. We show that wild-type, but not mutant, p53 can repress Pol I transcription from a human rRNA gene promoter in cotransfection assays. Furthermore, we show that recombinant p53 inhibits rRNA transcription in a cell-free transcription system. In agreement with these results, p53-null epithelial cells display an increased Pol I transcriptional activity compared to that of epithelial cells that express p53. However, both cell lines display comparable Pol I factor protein levels. Our biochemical analysis shows that p53 prevents the interaction between SL1 and UBF. Protein-protein interaction assays indicate that p53 binds to SL1, and this interaction is mostly mediated by direct contacts with TATA-binding protein and TAF(I)110. Moreover, template commitment assays show that while the formation of a UBF-SL1 complex can partially relieve the inhibition of transcription, only the assembly of a UBF-SL1-Pol I initiation complex on the rDNA promoter confers substantial protection against p53 inhibition. In summary, our results suggest that p53 represses RNA Pol I transcription by directly interfering with the assembly of a productive transcriptional machinery on the rRNA promoter.

Identification and chromosomal location of a new tandemly repeated DNA in maize

Two clones of a new family of tandemly repeated DNA sequences have been isolated from a maize random genomic DNA library. MR68 is 410 bp, representing a monomeric unit and MR77 is 1222 bp, containing three units. The copy number was estimated to be about 3000 per 1C maize genome. Its methylation pattern was also determined. Fluorescent in situ hybridization (FISH) indicates that the sequence is located on the subtelomeric region of the long arm of chromosomes 3 and 6, as well as on the satellite of chromosome 6.