Variation of resistance in barley against biotypes 1 and 2 of the Russian wheat aphid (Hemiptera: Aphididae)

The Russian wheat aphid, Diruaphis noxia (Kurdjumov) (Hemiptera: Aphididae), is globally one of the most devastating pests of bread wheat, Tritium aestivum L.; durum wheat, Triticum turgidum L.; and barley, Hordeum vulgare L. Host plant resistance is the foundation for cereal insect pest management programs, and several sources of D. noxia resistance have been incorporated in cultivars to manage D. noxia damage. The emergence of D. noxia North American biotype 2 (RWA2) in Colorado has made all known Dn genes vulnerable except the Dn7 gene from rye, Secale cereale, and has warranted exploration for sources of resistance to both RWA1 and RWA2. The category of resistance in resistant donor plants may exert selection pressure over the aphid population to form a new virulent population. In the current study, we report tolerance and antibiosis resistance to RWA1 and RWA2 in the barley genotype 'Stoneham'. The rate and degree of expression of resistance in Stoneham against RWA1 and RWA2, although not similar, are greater than the partial resistance in 'Sidney'. Antixenosis resistance to RWA1 or RWA2 was not observed in Sidney or Stoneham. The tolerance identified in Stoneham is encouraging because it may delay D. noxia biotype selection and fits well in a dryland barley cropping system.

Serum S100B levels in patients after cardiac surgery: possible sources of contamination

BACKGROUND

S100B protein is considered to be a potential marker of brain damage. The aim of our study was to determine the contamination effect of retransfused blood on the serum S100B concentrations in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) and to differentiate between this simple contamination effect and its possible enhancement by haemolysis.

METHODS

The first part of the study was performed in a group of 10 patients scheduled for coronary artery bypass grafting. Baseline S100B level was determined in a blood sample drawn from the radial artery before skin incision. After performing the distal anastomosis, additional blood samples were drawn from 1) the radial artery, 2) the aortic root catheter, 3) the pericardial space, and 4) CPB suction. To study the possible haemolytic effect on serum S100B levels, a second group of 23 patients was studied. S100B concentrations were determined in samples drawn simultaneously from the radial artery and bypass circuit after the end of CPB. Further samples from the retransfusion blood bag were analysed after one, two and three hours.

RESULTS

Blood samples from the pericardial space and CPB suction exhibited significantly higher levels of S100B than the samples drawn from the peripheral artery and aortic root catheter in the first group of patients. No significant differences between the S100B levels in the peripheral blood and aortic root catheter were detected. In the second group, S100B was significantly elevated in the samples taken from the retransfusion blood bag in comparison with peripheral blood. S100B levels remained stable during the whole follow-up period.

CONCLUSION

The results of our study show increased serum S100B levels caused by contamination originating in the mediastinal tissues. Storage of blood in the retransfusion bag and haemolysis can be excluded as sources of contamination. The role of S100B in perioperative monitoring of patients undergoing cardiac surgery remains to be established and should be confirmed by further studies using neuropsychological tests and imaging techniques.

Global gene expression analysis to identify molecular markers of uterine receptivity and embryo implantation

Infertility and spontaneous pregnancy losses are an enduring problem to women's health. The establishment of pregnancy depends on successful implantation, where a complex series of interactions occurs between the heterogeneous cell types of the uterus and blastocyst. Although a number of genes are implicated in embryo-uterine interactions during implantation, genetic evidence suggests that only a small number of them are critical to this process. To obtain a global view and identify novel pathways of implantation, we used a dual screening strategy to analyze the expression of nearly 10,000 mouse genes by microarray analysis. Comparison of implantation and interimplantation sites by a conservative statistical approach revealed 36 up-regulated genes and 27 down-regulated genes at the implantation site. We also compared the uterine gene expression profile of progesterone-treated, delayed implanting mice to that of mice in which delayed implantation was terminated by estrogen. The results show up-regulation of 128 genes and down-regulation of 101 genes after termination of the delayed implantation. A combined analysis of these experiments showed specific up-regulation of 27 genes both at the implantation site and during uterine activation, representing a broad diversity of molecular functions. In contrast, the majority of genes that were decreased in the combined analysis were related to host immunity or the immune response, suggesting the importance of these genes in regulating the uterine environment for the implanting blastocyst. Collectively, we identified genes with recognized roles in implantation, genes with potential roles in this process, and genes whose functions have yet to be defined in this event. The identification of unique genetic markers for the onset of implantation signifies that genome-wide analysis coupled with functional assays is a promising approach to resolve the molecular pathways required for successful implantation.

Emotional considerations and attending involvement ameliorates organ donation in brain dead pediatric trauma victims

PURPOSE

The purpose of this study was to ascertain a strategy for maximizing parental consent for organ donation in traumatically injured children suffering from brain death. Our hypothesis was that appropriate attending surgeon involvement and delay in evaluating children for brain death leads to an increased percentage of organ donors.

METHODS

From January 1993 to August 1999, the records of all children who died in a Level I trauma center were evaluated. Those children suffering brain death that were suitable for organ donation were entered into the study. Cases were reviewed for patient demographics, time to entry into brain death protocol (measured from time of admission), time to parent notification about brain death (measured from time of admission), specific attending involved in the case (with level of involvement), and success of organ donation request. In all, 43 charts were reviewed.

RESULTS

Of 43 deaths, 33 were deemed suitable for donation. Age of suitable donors ranged from 1 month to 18 years. In all, 11 attending physicians were involved in the care of these children. Overall, 20 of 33 were organ donors (60%). When the attending surgeon was involved, donation success for organ retrieval was 86%, whereas if the attending was not involved personally, the success rate dropped to 23% (p < 0.04). One senior pediatric surgeon obtained a success rate of 12 of 12 children. It was this surgeon's policy to not initiate brain death protocols in children immediately on entry into the emergency room, but rather to delay initiation until family could be gathered and spend time with the affected child in order that the family could recover from the initial shock of trauma (always at least overnight). When time to initiation of brain death protocol was examined, success was obtained when a delay of 15.5 hours was respected, versus 7.0 hours when donation was requested but denied (p < 0.03).

CONCLUSION

These data indicate that attending involvement is important when parents of brain dead children are asked about organ retrieval (p < 0.04). Delay in initiating brain death protocols in order for family members to deal with the shock of the initial trauma appears to increase willingness to participate in organ donation.

Comparative analysis of pharmacologic and/or genetic disruption of cyclooxygenase-1 and cyclooxygenase-2 function in female reproduction in mice

Cyclooxygenase (COX)-derived prostaglandins are critical in female reproduction. Gene targeting studies show that ovulation, fertilization, implantation, and decidualization are defective in COX-2 deficient mice. We used genetic and pharmacologic approaches to perturb COX function and examine the differential and synergistic effects of inhibition of COX-1, COX-2, or of both isoforms on reproductive outcomes during early pregnancy in mice. The results demonstrate that simultaneous inhibition of COX-1 and COX-2 produces more severe effects on early pregnancy events than inhibition of either isoform alone. The effects of pharmacological inhibition of COX-2 on female reproductive functions were less severe than the null mutation of the COX-2 gene. A combined approach showed that COX-2 inhibition in COX-1(-/-) mice induced complete reproductive failure, suggesting a lack of alternative sources of prostaglandin synthesis. This investigation raises caution regarding the indiscriminate use of COX inhibitors and shows for the first time the distinct and overlapping pathways of the cyclooxygenase systems in female reproduction.

Coordinated regulation of fetal and maternal prostaglandins directs successful birth and postnatal adaptation in the mouse

Cyclooxygenase (COX)-derived prostaglandins (PGs) regulate numerous maternal-fetal interactions during pregnancy. PGs stimulate uterine contractions and prepare the cervix for parturition, whereas in the fetus, PGs maintain patency of the ductus arteriosus (DA), a vascular shunt that transmits oxygenated placental blood to the fetal systemic circulation. However, the origin and site of action of these PGs remain undefined. To address this, we analyzed mice lacking COX-1 (null mutation) or COX-2 (pharmacologic inhibition) or pups with a double null mutation. Our results show that COX-1 in the uterine epithelium is the major source of PGs during labor and that COX-1(-/-) females experience parturition failure that is reversible by exogenous PGs. Using embryo transfer experiments, we also show that successful delivery occurs in COX-1(-/-) recipient mothers carrying wild-type pups, establishing the sufficiency of fetal PGs for parturition. Although patency of the DA is PG dependent, neither COX-1 nor COX-2 expression was detected in the fetal or postnatal DA, and offspring with a double null mutation died shortly after birth with open DAs. These results suggest that DA patency depends on circulating PGs acting on specific PG receptors within the DA. Collectively, these findings demonstrate the coordinated regulation of fetal and maternal PGs at the time of birth but raise concern regarding the use of selective COX inhibitors for the management of preterm labor.

Host cyclooxygenase-2 modulates carcinoma growth

Cyclooxygenase-2 (COX-2; Ptgs2) acts as a tumor promoter in rodent models for colorectal cancer, but its precise role in carcinogenesis remains unclear. We evaluated the contribution of host-derived COX-1 and COX-2 in tumor growth using both genetic and pharmacological approaches. Lewis lung carcinoma (LLC) cells grow rapidly as solid tumors when implanted in C57BL/6 mice. We found that tumor growth was markedly attenuated in COX-2(-/-), but not COX-1(-/-) or wild-type mice. Treatment of wild-type C57BL/6 mice bearing LLC tumors with a selective COX-2 inhibitor also reduced tumor growth. A decrease in vascular density was observed in tumors grown in COX-2(-/-) mice when compared with those in wild-type mice. Because COX-2 is expressed in stromal fibroblasts of human and rodent colorectal carcinomas, we evaluated COX-2(-/-) mouse fibroblasts and found a 94% reduction in their ability to produce the proangiogenic factor, VEGF. Additionally, treatment of wild-type mouse fibroblasts with a selective COX-2 inhibitor reduced VEGF production by 92%.

Implantation and decidualization defects in prolactin receptor (PRLR)-deficient mice are mediated by ovarian but not uterine PRLR

PRL and its homologs accomplish their biological effects through the PRL receptor (PRLR). We evaluated the expression and function of PRLR in the embryo and uterus during the periimplantation period because PRLR deficiency results in implantation failure. In wild-type mice, PRLR expression was localized to undecidualized stromal cells in the antimesometrial border on days 6-8 of pregnancy. A small population of PRLR-expressing cells was observed adjacent to the ectoplacental cone in the mesometrial stroma. Low levels of PRLR expression were also detected in the developing embryo on days 6-8. To determine the significance of PRLR expression in this distribution, we examined implantation and decidualization in PRLR-/- mice. Progesterone (P4) administration rescued infertility in PRLR-/- mice from the periimplantation period to midgestation. Artificially induced decidualization was absent in pseudopregnant PRLR-/- mice but was identical to wild-type in P4-treated PRLR-/- mice. Furthermore, wild-type and P4-treated PRLR-/- mice had similar expression of the implantation-specific genes, LIF, amphiregulin, HB-EGF, COX-1, COX-2, PPARdelta, Hoxa-10, cyclin-D3, VEGF, and its receptors, Flk-1 and neuropilin-1. Together, these results show that luteal P4 production via ovarian PRLR signaling is required for implantation and early pregnancy. The function of uterine PRLR remains unclear. However, the eventual loss of pregnancy in P4-treated PRLR-/- mice suggests that uterine PRLR may be essential for the support of late gestation.

Molecular signaling in uterine receptivity for implantation

Successful implantation is the result of an intimate 'cross-talk' between the blastocyst and uterus in a temporal and cell-specific manner. Thus, both the uterine and embryonic events must be examined to better understand this process. Although various aspects and molecules associated with these events have been explored, a comprehensive understanding of the implantation process is still very limited. In this review, we have highlighted the importance of the blastocyst's activity state and the receptive state of the uterus in determining the 'window' of implantation. In this context, we provide a testable scheme that signifies the important roles of various key molecules in embryo-uterine interactions during implantation.

Intraoperative embolus formation during cardiopulmonary bypass affects the release of S100B

BACKGROUND

Intraoperative thromboembolism and the systemic inflammatory reaction are thought to play a role in causing cerebral dysfunction following cardiopulmonary bypass (CPB). Increased levels of S100B, an astroglial protein, have been linked to neuropsychological deficits after CPB. The present study investigated whether S100B release correlates with intraoperative embolus formation, thrombin formation, or the release of inflammatory parameters.

METHODS

40 patients undergoing coronary artery bypass grafting were included. Blood samples were taken before, during, and after CPB, and levels of S100B, thrombin-antithrombin complex (TAT), complement C5a, and interleukin 8 were analysed. Embolus formation was assessed by Doppler ultrasound at the arterial line of CPB.

RESULTS

The release of S100B correlated with embolus count (r = 0.42; p = 0.009) and TAT formation (r = 0.71; p = 0.0001). The correlation of S100B with interleukin 8 (r = 0.58; p = 0.0001) was due to the dependence of both parameters on bypass time (r = 0.29; p = 0.075, partial correlation). A correlation of S100B with C5a formation could not be observed.

CONCLUSIONS

S100B release is related to embolus and thrombin formation during CPB, indicating that thrombofibrinous embolism is involved in perioperative brain damage. Inflammatory parameters (i.e. interleukin 8 and C5a) seem to have no influence on S100B release.

COX-2 compensation in the uterus of COX-1 deficient mice during the pre-implantation period

Prostaglandins (PGs) produced by cyclooxygenase (COX) participate in many aspects of female reproduction. The two isoforms of cyclooxygenase, COX-1 and COX-2, have distinct expression patterns in the mouse uterus during the peri-implantation period and suggest their independent contribution to uterine PGs. Using wild type and COX-1(-/-) mice, we examined the role of COX-1-derived PGs on day 4 of pregnancy, when its expression is maximal. Uterine vascular permeability was measured by 125I-labeled bovine serum albumin (BSA) uptake, and PG content was measured by gas chromatography-mass spectrometry. Vascular permeability and PG concentrations were reduced in COX-1(-/-) mice, but by less than the expected amount. After ovariectomy, uterine vascular permeability declined in both groups, but returned to baseline in wild type and was exaggerated in COX-1(-/-) females after treatment with ovarian steroids. Most importantly, COX-1(-/-) uteri displayed COX-2 expression on the morning of day 4, when COX-2 is normally absent. This hybridization pattern resembles the native expression of COX-1, and may partially offset the loss of COX-1-derived PGs. These data indicate that COX-1-derived PGs are important during uterine preparation for implantation, and that COX-2 compensation occurs in the absence of COX-1.

Murine alpha1-adrenoceptor subtypes. I. Radioligand binding studies

Alpha1-adrenoceptors were identified in murine tissues by [3H]prazosin saturation binding studies, with a rank order of cerebral cortex > cerebellum > liver > lung > kidney > heart > spleen, with the spleen not exhibiting detectable expression. Competition binding studies were performed with 5-methylurapidil, BMY 7378, methoxamine, (+)-niguldipine, noradrenaline, SB 216469 and tamsulosin. On the basis of monophasic low-affinity competition by BMY 7378, alpha1D-adrenoceptors were not detected at the protein level in any tissue. On the basis of competition studies with the alpha1A/alpha1B-discriminating drugs, alpha1B-adrenoceptors appeared to be the predominant or even the sole subtype in murine liver, lung and cerebellum, whereas murine cerebral cortex and kidney contained approximately 30% and 50% of alpha1A-adrenoceptors, respectively. The affinities of the various competitors in the murine tissues were quite similar to those reported from other species. The ratio of high- and low-affinity sites for tamsulosin did not in all cases match the percentages of alpha1A- and alpha1B-adrenoceptors detected by the other competitors; however, the low-affinity component of the tamsulosin competition curves was abolished in the cerebral cortex of alpha1B-adrenoceptor knockout mice. Treatment with chloroethylclonidine (10 microM, 30 min, 37 degrees C) inactivated the alpha1-adrenoceptors in all tissues by >75%. When the concentration-dependent inactivation of tissue alpha1B-adrenoceptors (liver) and tissue alpha1A-adrenoceptors (cerebral cortex from alpha1B-adrenoceptor knockout mice) was compared, alpha1A-adrenoceptors were only slightly less sensitive toward chloroethylclonidine than alpha1B-adrenoceptors. We conclude that murine tissues express alpha1A- and alpha1B-adrenoceptors, which are largely similar to those in other species. However, the tissue-specific distribution of subtypes may differ from that of other species.

Expression of neu differentiation factor during the periimplantation period in the mouse uterus

Complex cellular interactions occur between the blastocyst and the uterus during implantation. The expression of various polypeptide growth factors and their receptors in the uterus and/or blastocyst during the periimplantation period suggest that growth factors participate in the implantation process. Neu differentiation factor (NDF) is a member of the epidermal growth factor (EGF) family of growth factors and is represented by multiple conserved isoforms. The expression of several EGF-like ligands in the periimplantation uterus has been characterized, including EGF, heparin binding-EGF, transforming growth factor alpha, amphiregulin, betacellulin, and epiregulin. We analyzed the expression pattern of NDF in the periimplantation mouse uterus because of its mitogenic and differentiation-promoting effects. By using Northern analysis and isoform-specific polymerase chain reaction, we found that multiple isoforms are expressed in the periimplantation uterus. NDF displays a highly restricted temporal and spatial expression, with autoradiographic signals localized to the uterine stroma immediately surrounding the implanting blastocyst. NDF expression was absent in mice with delayed implantation but briefly reappeared with the same restricted distribution after termination of the delay by an injection of estrogen. Taken together, these results suggest that an activated blastocyst is required for the expression of NDF and that multiple isoforms may be involved in the complex network of cell-signaling events between the implanting blastocyst and the receptive uterus.

A randomized trial of radical cystectomy versus radical cystectomy plus cisplatin, vinblastine and methotrexate chemotherapy for muscle invasive bladder cancer

PURPOSE

Standard treatment for muscle invasive transitional cell cancer of the bladder is radical cystectomy. Despite careful staging, the majority of cancers with regional lymph node involvement and/or invasion to adjacent organs eventually recur. We investigated the benefit of chemotherapy with cisplatin, methotrexate and vinblastine (CMV) after radical cystectomy.

MATERIALS AND METHODS

A prospective trial was done in which patients were randomized after cystectomy to receive either 4 cycles of CMV chemotherapy or observation. At relapse, patients were treated with standard CMV chemotherapy for metastatic disease at our institution.

RESULTS

Of 55 patients who entered this trial 1 was ineligible and in 4 it is too soon to be evaluated. Of the 50 evaluable patients 25 were randomized to receive adjuvant CMV chemotherapy and 25 were observed. In the CMV arm 12 (48%) and in the observation arm 5 (25%) never had recurrence. With a median followup of 62 months and no patient with less than 2 years of followup, the freedom from progression in the adjuvant chemotherapy group was superior to that in the observation group (median 37 versus 12 months, respectively, p = 0.01). Median survival in the adjuvant group was 63 months compared to 36 months for the observation group. Surprisingly, some cases with relapse could be salvaged with CMV chemotherapy, perhaps contributing to this lack of difference in overall survival (p = 0.32).

CONCLUSIONS

Treatment with CMV chemotherapy after radical cystectomy is an acceptable approach in patients with stages p3b and p4N0 or N1 transitional cell carcinoma of the bladder. Further studies must be performed to determine whether these results can be extrapolated to patients with more limited disease (stages p2 and p3a) who are currently treated with radical cystectomy or definitive irradiation.

Medial and lateral antebrachial cutaneous nerve blocks: an easily learned regional anesthetic for forearm arteriovenous fistula surgery

BACKGROUND AND OBJECTIVES

Forearm arteriovenous fistula insertion is commonly performed to facilitate hemodialysis. This study was undertaken to assess the use of medial and lateral antebrachial cutaneous nerve blocks to provide anesthesia for this surgery.

METHODS

Twelve patients with end-stage renal failure, presenting for insertion or revision of a forearm Gortex arteriovenous fistula, were anesthetized by local block of the medial and lateral antebrachial cutaneous nerves with a mepivacaine-bupivacaine mixture.

RESULTS

Ten patients required no further local anesthetic for surgery. Two patients required minor local anesthetic supplementation in the proximal radial nerve distribution.

CONCLUSIONS

Anesthesia for forearm arteriovenous fistula insertion can be provided by an easily performed regional anesthetic technique, which may have advantages over brachial plexus blocks and incisional field blocks.

Breast feeding in neonatal alloimmune thrombocytopenia

Infants with neonatal alloimmune thrombocytopenia are at risk of severe intracranial haemorrhage. Placental transfer of maternal immunoglobulin G (IgG) directed against fetal platelet antigens is known to be the underlying mechanism. Since breast milk contains IgG it is theoretically possible that breast feeding of these infants could cause thrombocytopenia. The following case report shows that an infant with neonatal alloimmune thrombocytopenia may be safely breast fed, even when the breast milk contains the platelet specific antibody (HPA-1a).