Analysis of trajectory changes and predictive factors of sense of coherence in patients after colorectal cancer surgery

OBJECTIVE

To investigate the trajectories and potential categories of changes in the sense of coherence (SOC) in patients after colorectal cancer surgery and to analyze predictive factors.

METHODS

From January to July 2023, 175 patients with colorectal cancer treated at a tertiary Grade A oncology hospital in Jiangsu Province were selected as the study subjects. Prior to surgery, SOC-13 scale, Patient-Generated Subjective Global Assessment (PG-SGA), Brief Illness Perception Questionnaire (BIPQ), and Social Support Rating Scale (SSRS) were used to survey the patients. SOC levels were measured multiple times at 1 week, 1 month, and 3 months post-surgery. Growth Mixture Modeling (GMM) was applied to fit the trajectory changes of SOC in patients after colorectal cancer surgery. Multinomial logistic regression was used to analyze the predictive factors of SOC trajectory changes.

RESULTS

The SOC scores of patients at points T1-T4 were (65.27 ± 9.20), (63.65 ± 10.41), (63.85 ± 11.84), and (61.56 ± 12.65), respectively. Multinomial logistic regression results indicated that gender, employment status, disease stage, household monthly income, intestinal stoma, nutritional status, illness perception, and social support were predictors of SOC trajectory changes (P < 0.05).

CONCLUSION

There is heterogeneity in the trajectory changes of SOC in patients after colorectal cancer surgery. Healthcare professionals should implement early precision interventions based on the patterns of changes and predictive factors in each trajectory category.

Identification of abnormal closed-loop pathways in patients with MRI-negative pharmacoresistant epilepsy

Epilepsy is a disorder of brain networks, that is usually combined with cognitive and emotional impairment. However, most of the current research on closed-loop pathways in epilepsy is limited to the neuronal level or has focused only on known closed-loop pathways, and studies on abnormalities in closed-loop pathways in epilepsy at the whole-brain network level are lacking. A total of 26 patients with magnetic resonance imaging-negative pharmacoresistant epilepsy (MRIneg-PRE) and 26 healthy controls (HCs) were included in this study. Causal brain networks and temporal-lag brain networks were constructed from resting-state functional MRI data, and the Johnson algorithm was used to identify stable closed-loop pathways. Abnormal closed-loop pathways in the MRIneg-PRE cohort compared with the HC group were identified, and the associations of these pathways with indicators of cognitive and emotional impairments were examined via Pearson correlation analysis. The results revealed that the abnormal stable closed-loop pathways were distributed across the frontal, parietal, and occipital lobes and included altered functional connectivity values both within and between cerebral hemispheres. Four abnormal closed-loop pathways in the occipital lobe were associated with emotional and cognitive impairments. These abnormal pathways may serve as biomarkers for the diagnosis and guidance of individualized treatments for MRIneg-PRE patients.

Structural and functional changes in the default mode network in drug-resistant epilepsy

PURPOSE

To investigate brain network properties and connectivity abnormalities of the default mode network (DMN) in drug-resistant epilepsy (DRE). The study was based on probabilistic fiber tracking and functional connectivity (FC) analysis, to explore the structural and functional connectivity patterns change between frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE).

METHODS

A total of 33 DRE patients (18 TLE and 15 FLE) and 30 healthy controls (HCs) were recruited. The volume fraction of the septal brain region of the DMN in DRE was calculated using FreeSurfer. The FC analysis was performed using Data Processing and Analysis for Brain Imaging in MATLAB. The structural connections between brain regions of the DMN were calculated based on probabilistic fiber tracking.

RESULTS

The left precuneus (PCUN) volumes in epilepsy groups were lower than that in HCs. Compared with FLE, TLE showed reduced FC between the left hippocampus (HIP) and PCUN/medial frontal gyrus, and between the right inferior parietal lobule (IPL) and right superior temporal gyrus. Compared with HCs, FLE showed increased FCs between the right IPL and occipital lobe, and between the left superior frontal gyrus (SFG) and bilateral superior temporal gyrus. In terms of structural connectivity, TLE exhibited increased connectivity strength between the left SFG and left PCUN, and showed reduced connection strength between the left HIP and left posterior cingulate gyrus/left PCUN, when compared with the FLE.

CONCLUSIONS

TLE and FLE patients showed structural and functional changes in the DMN. Compared with FLE patients, the TLE patients showed reduced structural and functional connection strengths between the left HIP and PCUN. These alterations in connection strengths holds promise for the identification of TLE and FLE.

[Efficacy and safety of endothelin receptor antagonists combined with phosphodiesterase 5 inhibitor in the treatment of pulmonary arterial hypertension: a network meta-analysis]

Objective: To examine the efficacy and safety of endothelin receptor antagonists (ERA) combined with phosphodiesterase 5 inhibitors (PDE5i) in the treatment of pulmonary artery hypertension (PAH). Methods: Computer-based retrieval was performed on PubMed, Cochrane Library, CNKI, Wanfang, and VIP database (up to February 12th, 2021). Randomized controlled trials about endothelin receptor antagonists (ERAs) or PDE5i in patients with PAH were collected. The change of 6-minute walking distance (6MWD) in 12-16 weeks was used as primary outcome index. Case fatality rate, worsening clinical events, WHO functional class (FC) improvement, adverse events (AEs), serious adverse events (SAE) were the key secondary outcomes indicators. STATA 16.0 software was used for network meta-analysis, and the pooled estimates of odds ratios (ORs) or weighted mean differences (WMDs) and 95% confidence intervals (CIs) of the results were shown. To help explain ORs and WMDs, we used the surface under the cumulative ranking curve (SUCRA) to calculate the probability of each intervention. Results: We included 29 trials with 5 949 participants. In network meta-analysis, Bosentan combined with Sildenafil (WMD=53.93, 95%CI=6.19-101.66) had shown the greatest improvement in 6MWD compared with placebo, followed by Bosentan combined with Tadalafil (WMD=50.84, 95%CI=7.05-94.62), Ambrisentan combined with Tadalafil (WMD=46.67, 95%CI=15.88-77.45), Bosentan (WMD=29.44, 95%CI=5.86-53.02), Ambrisentan (WMD=23.90, 95%CI=0.31-47.48) and Macitentan (WMD=21.57, 95%CI=2.45-40.69). According to SUCRA, the effects of different intervention measures on improving 6MWD in patients with arterial pulmonary hypertension were as follows: Bosentan+Sildenafil (82.9%)>Bosentan+Tadalafil (78.4%)>Ambrisentan+Tadalafil (77.1%)>Bosentan (49.2%)>Sildenafil (48.5%)>Ambrisentan (40.3%)>Macitentan (37.3%)>Tadalafil (33.0%)>Placebo (3.3%). For the WHO functional class, Sildenafil (OR=2.90, 95%CI=1.04-8.08) was optimal compared with placebo, followed by Bosentan (OR=2.15, 95%CI=1.15-4.04), and there was no significant difference in the rest. For clinical worsening, Bosentan combined with Tadalafil (OR=0.08, 95%CI=0.01-0.49) performed best compared with placebo, followed by Bosentan (OR=0.20, 95%CI=0.11-0.38), Bosentan combined with Sildenafil (OR=0.21, 95%CI=0.09-0.46), Ambrisentan combined with Tadalafil (OR=0.27, 95%CI=0.15-0.50), Sildenafil (OR=0.33, 95%CI=0.17-0.66) and Tadalafil (OR=0.44, 95%CI=0.21-0.90). There was no statistical difference between all interventions and placebo in terms of the incidence of adverse events and serious adverse events. For case fatality rate, Ambrisentan (OR=0.28, 95%CI=0.11-0.74) was statistically superior to placebo and there was no statistics difference in the rest. Conclusions: The combination therapy of ERAs and PDE5i performed well in the short-term improvement of motor function. Furthermore, there was no significant difference with monotherapy in terms of safety. However, it is worth emphasizing that the choice of treatment should be based on the patient's individualized situation and the patient's requirements.

MicroRNA: a novel biomarker and therapeutic target to combat autophagy in diabetic nephropathy

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease worldwide and is associated with increased morbidity and mortality in patients with both type 1 and type 2 diabetes. Early treatment of DKD can prevent or slow its progression. Some studies suggest that traditional risk factors such as albuminuria do not effectively predict DKD progression, and other predictors have yet to be characterized and validated. Therefore, there is an urgent need to identify sensitive and easily detectable biomarkers to monitor the decline in renal function. MicroRNAs (miRNAs) have recently emerged as important regulators that are ubiquitous in human tissues and bodily fluids, numerous diseases, including early DKD. Recent developments have revealed that miRNAs-mediated post-transcriptional regulation of gene expression represents an integral part of the autophagy regulatory network. In this review, we explored the utility of miRNAs as biomarkers for the early detection and progression of DKD. We also examined some of the molecular mechanisms by which miRNAs manipulate the autophagic machinery to maintain cellular homeostasis during DKD. A better understanding of the interaction between miRNAs and autophagy may ultimately benefit future DKD diagnosis and therapy.

Emergency management in fever clinic during the outbreak of COVID-19: an experience from Zhuhai

Coronavirus disease 2019 (COVID-19) is a global health threat. A hospital in Zhuhai adopted several measures in Fever Clinic Management (FCM) to respond to the outbreak of COVID-19. FCM has been proved to be effective in preventing nosocomial cross infection. Faced with the emergency, the hospital undertook creative operational steps in relation to the control and spread of COVID-19, with special focuses on physical and administrative layout of buildings, staff training and preventative procedures. The first operational step was to set up triaging stations at all entrances and then complete a standard and qualified fever clinic, which was isolated from the other buildings within our hospital complex. Secondly, the hospital established its human resource reservation for emergency response and the allocation of human resources to ensure strict and standardised training methods through the hospital for all medical staff and ancillary employees. Thirdly, the hospital divided the fever clinic into partitioned areas and adapted a three-level triaging system. The experiences shared in this paper would be of practical help for the facilities that are encountering or will encounter the challenges of COVID-19, i.e. to prevent nosocomial cross infection among patients and physicians.

The tumor suppressor NOR1 suppresses cell growth, invasiveness, and tumorigenicity in glioma

Oxidored-nitro domain-containing protein 1 (NOR1) is a tumor suppressor downregulated in various human cancers, including nasopharyngeal carcinoma (NPC), lung cancer, and testicular cancer. NOR1 protein is highly expressed in the normal brain; however, its role in brain tumors remains unknown. In this study, we demonstrated that the NOR1 protein level was decreased in glioma tissue samples as compared to its normal counterpart. Exogenously expressed NOR1 protein in glioma U251 cells inhibits tumor cell proliferation, migration, and invasion. Re-expression of NOR1 induced cell cycle S to G2 phase arrest and suppressed its tumorigenicity in nude mice. Overexpression of NOR1 in U251 cells also led to a decrease of Ki67 expression in xenografts. Transcriptomic analysis revealed that NOR1 expression altered the expression of genes favored cell proliferation. Among the differentially expressed genes, FOXR2, a member of the FOX gene family, which promotes glioma progression, was decreased in NOR1 expressing cells. The downregulation of FOXR2 by NOR1 was validated in vitro and in vivo. Our findings suggest for the first time that NOR1 suppresses glioma progression via modulating the FOXR2 expression.

Direct medical burden of antimicrobial-resistant healthcare-associated infections: empirical evidence from China

BACKGROUND

Antimicrobial resistance (AMR) and healthcare-associated infections (HAIs) are among the biggest global public health challenges, and overlap widely. These infections cause significant morbidity and mortality, put pressure on health systems, and incur rising direct and indirect costs.

AIM

This study analysed the direct medical burden attributable to AMR-HAIs in Chinese public tertiary hospitals, and aimed to inform both the medical regulators and hospital managers for better control of HAIs and containment of AMR.

METHODS

The propensity score matching method (γ= 0.25σ, nearest neighbor 1:1 matching) was applied to conduct a retrospective cohort study in five public tertiary hospitals in the Hubei province of China during 2013-2015. Descriptive analysis, Pearson's chi-squared test, Mann-Whitney U-test, Wilcoxon signed-rank test and paired/independent Z/T test were conducted. The statistically significant level was set at P<0.05.

FINDINGS

From 2013 to 2015 overall, the additional total medical expenditure per HAI-AMR inpatient was US$15,557.25 compared with that of the non-HAIs, and the additional length of per hospital stay of the HAI-AMR inpatient was 41 days compared with that of the non-HAIs (P<0.001).

CONCLUSIONS

In combination with AMR, HAIs caused significant additional medical expenses and affected the turnover rate of hospital beds. Most of the increased medical costs fell to patients and their families. These findings call for more effective control of HAIs and containment of AMR. A national study is needed to estimate the medical, social and economic burden of HAIs in combination with AMR.

Clinical analysis of gastroenteropancreatic neuroendocrine tumor with liver metastasis, compared with primary hepatic neuroendocrine tumor

OBJECTIVE

The objective was to study the clinicopathologic features, grading, treatment protocols, and prognostic of gastroenteropancreatic neuroendocrine tumor (NET) with liver metastasis and primary hepatic NET.

MATERIALS AND METHODS

The clinical data of 34 patients with hepatic NET were retrospectively reviewed. According to the primary tumor location and 2010 World Health Organization classification, the cases were categorized to analyze the clinicopathologic features, treatment condition, and prognostic factors.

RESULTS

There was a marked male predominance either in gastroenteropancreatic NET liver metastasis group or primary group. Primary hepatic NET is mostly single nodule located in the right lobe of liver, and the metastatic hepatic NET is mostly from pancreas with multiple nodules and metastasizes to both lobes of the liver, with a high degree of malignancy and poor prognosis. There are 17 cases (50%) of NET and 17 cases (50%) of neuroendocrine carcinoma (NEC) in all the 34 patients of this study. The mitotic figure and Ki-67 proliferation index are both higher in NEC group than in NET group, which indicated highly malignancy of the NEC. The 5-year disease-free survival (DFS) rates for primary group and metastatic group were 30% and 40%, respectively (P > 0.05), while the 5-year survival rates were 35% and 66%, respectively (P > 0.05). Different tumor grade was found closely associated with 5-year DFS (P < 0.05) and overall survival (OS) (P < 0.05) in both groups. Furthermore, we found 5-year DFS of patients with primary site of the tumor located in the gastrointestinal tract was much lower than that located in pancreas (P < 0.05), while the 5-year OS showed no significant differences between two groups (P > 0.05).

CONCLUSIONS

Surgery is an effective method for the treatment of hepatic NET; tumor grading is an important determinant factor of prognosis.

Identification of Campylobacter jejuni and determination of point mutations associated with macrolide resistance using a multiplex TaqMan MGB real-time PCR

AIMS

The aim of the study was to develop a multiplex real-time PCR method to identify Campylobacter jejuni containing mutations commonly associated with macrolide resistance.

METHODS AND RESULTS

A multiplex fluorescence real-time PCR assay was developed based on TaqMan minor groove binder (MGB) probes. The VS1-MGB probe was designed based on the VS1 gene and was used to identify Camp. jejuni. The 23S rDNA-MGB probe was designed to distinguish macrolide resistance mutations in 23S rDNA, while 57D-MGB and 74D-MGB were designed to detect resistance mutations in ribosomal protein L4. The specificity and accuracy of our method were identical to the conventional biochemical tests, mapA PCR, minimum inhibitory concentration (MIC) determination and DNA sequencing. The linear detection limit of the method was 0·03 ng genomic DNA and three colony formation unit (CFU) per reaction. In 6 of 18 cases, the nature of Erythromycin resistance could be correctly determined from natural isolates; absence of the tested mutations was demonstrated in the remaining four resistant isolates.

CONCLUSIONS

A multiplex TaqMan MGB real-time PCR assay with high specificity and accuracy was developed to simultaneously identify Camp. jejuni and detect the gene mutations associated with macrolide resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multiplex method can potentially simplify the identification of Camp. jejuni and determine macrolide resistance due to mutations in 23S rDNA or ribosomal protein L4. This method has a potential for application in different research areas and molecular surveillance.

Placental miR-106a∼363 cluster is dysregulated in preeclamptic placenta

Preeclampsia (PE) is the leading cause of maternal and perinatal mortality and morbidity. MicroRNAs are strongly implicated in the pathogenesis of this syndrome. In current study, we performed a microarray assay to explore miRNA expression profile in the placenta, and found 11 upregulated and 7 downregulated miRNAs in preeclampsia. miR-363, plus other 5 member of miR-106a∼363 cluster was further examined and validated. These findings would facilitate further investigation of aberrant expression of miRNAs in the pathology of preeclampsia.

Short axis contact in the chaining of ellipsoidal particles of polar molecule dominated electrorheological fluid

We simulate the effect of the chaining direction of ellipsoidal particles of polar molecule dominated electrorheological (PM-ER) fluids using commercially available COMSOL Multiphysics® software for the distribution of electric field and the total electrostatic energy. It is proved that adding ferroelectric materials to the channels parallel to the short axis would make the short axis parallel to the field direction when the ellipsoidal particles are chained under an electric field. According to our simulation, while the concentration of the channels stays constant, the greater the dielectric constant of the inserted material, the stronger the maximum local electric field will be.

HTPAP gene on chromosome 8p is a candidate metastasis suppressor for human hepatocellular carcinoma

Our previous studies suggested that chromosome 8p deletion is associated with metastasis of hepatocellular carcinoma (HCC), in which some novel metastasis suppressor genes might be harbored. The present study aimed to identify the metastatic suppressor gene(s). A cDNA chip was constructed with the expressed sequence tags (ESTs) from chromosome 8p and used to compare the difference of expression profiling between the MHCC97-H and MHCC97-L cell lines with different metastatic potentials and similar genetic backgrounds. In all, 10 ESTs were significantly downregulated in MHCC97-H cell line with higher metastatic potential. One full-length gene, HTPAP (phosphatidic acid phosphatase type 2 domain containing 1B), was identified at chromosome 8p12. Sequencing and bioinformatic analyses revealed that HTPAP has 826 bp and encodes a putative protein of 175 amino acids with a transmembrane segment at the NH2 terminus, two protein kinase C phosphorylation site and one tyrosine kinase phosphorylation site. Its expression level in metastatic tumor tissues was much lower than that of primary HCC tissues. Both in vitro and in vivo assays suggested that HTPAP could suppress the invasion and metastasis of HCC. These suggested that HTPAP is a novel metastatic suppressor gene for HCC. The mechanism of the effect of HTPAP on HCC metastasis is not clear yet and deserves further investigation.

Randomized clinical trial of the effects of abdominal drainage after elective hepatectomy using the crushing clamp method

BACKGROUND

Abdominal drainage is a standard procedure after hepatectomy, but this practice has been challenged recently.

METHODS

Between September 2004 and March 2005, 120 consecutive patients who had undergone hepatic resection by the same surgical team were randomly allocated into drainage and no drainage groups (60 in each group). Patient characteristics, preoperative liver function, presence of cirrhosis, resection-related factors and postoperative complications were compared between the two groups.

RESULTS

The groups were comparable in terms of demographics, indications for surgery, preoperative liver function test results, presence of cirrhosis, extent of hepatectomy, intraoperative blood loss and requirement for blood transfusion. Symptomatic subphrenic collection and pleural effusion occurred in four patients (7 per cent) who had abdominal drainage and three (5 per cent) who did not. Local wound complications occurred in 17 (28 per cent) and two (3 per cent) patients respectively (P < 0.001). The postoperative hospital stay was similar in the two groups. Multivariate analysis indicated that the presence of cirrhosis and abdominal drainage were independently related to the development of postoperative wound complications.

CONCLUSION

Routine abdominal drainage is unnecessary after elective hepatectomy using the crushing clamp method.

Taking the rough with the smooth: foraging for particulate food in continuous time

This paper describes the development of the general dynamical model of foraging developed by Ollason (1980, Theoret. Popul. Biol. 18, 44-65) to predict foraging for particulate food in three different types of environment. In an environment containing particles of different types of food, the model predicts the selection of an approximately optimal diet; in an environment in which the particles occur in patches, the model predicts a time budget of patch occupancy that approximates to the optimal time budget; and in an environment containing patches of particles that regenerate by the addition of particles of food at constant rates, the model predicts that animals will dispose themselves among the patches approximately as predicted by the ideal free distribution. Where the predictions of the model depart from the predictions of optimal foraging theory, they are qualitatively similar to the observed departures of the behaviour of real animals from the predictions of optimal foraging theory. The model provides a general representation of the foraging decisions of animals whether they feed strictly continuously or discontinuously on particles of food, and does so without explicit reference to optimization processes.

Platelets promote the adhesion of human hepatoma cells with a highly metastatic potential to extracellular matrix protein: involvement of platelet P-selectin and GP IIb-IIIa

PURPOSE

To investigate the role and possible mechanisms of platelets in liver cancer metastasis.

METHODS

The optimum conditions of hepatoma cell adhesion to the extracellular matrix (ECM) were determined. The ability of cells to adhere to the ECM was compared between human hepatoma cell lines with a highly metastatic potential (MHCC97) and human hepatoma cell lines with a lower metastatic potential (SMMC7721). By using adhesion assays and inhibition studies in vitro, the effects of platelets and their specific adhesive molecules were compared via the ability of MHCC97 and SMMC7721 to adhere to ECM protein.

RESULTS

The SMMC7721 cell adhesion rate to vitronectin, fibronectin, and fibrinogen, respectively, was significantly lower than that of MHCC97 cells (44.9% vs 73.6%, 47.4% vs 76.4%, and 59.3% vs 80.6%, P<0.05). Both hepatoma cell adhesion to the ECM-bound platelets was unchanged whether the platelets were activated or not. SMMC7721 cell adhesion to the ECM was not affected by platelets, but MHCC97 cell adhesion to the ECM was significantly enhanced by platelets ( P<0.01). In addition, this effect was significantly reduced when either P-selectin or GP IIb-IIIa was blocked by monoclonal antibodies ( P<0.05, P<0.01). In the inhibition studies, the ability of SMMC7721 to adhere to the ECM-bound activated platelets was also lower than that of MHCC97 ( P<0.05). However, when GP IIb was blocked by antibody, the adhesion ability of both cells was similar ( P >0.05).

CONCLUSIONS

Human hepatoma cells with a highly metastatic potential proved to have a highly adhesive ability. MHCC97 cell adhesion to the ECM was significantly enhanced by platelets. The interaction of MHCC97 cells with the ECM-bound activated platelets may be mediated by platelet P-selectin and GP IIb-IIIa.

Fabrication of compact silver nanoshells on polystyrene spheres through electrostatic attraction

Nanoshells composed of close-packed silver nanocrystals have been fabricated on polystyrene spheres via direct electrostatic attraction at appropriate pH; the thickness and roughness of the shell can be readily controlled through a layer-by-layer technique.

AFLP analysis of genetic polymorphism and evolutionary relationships among cultivated and wild Nicotiana species

Amplified fragment length polymorphism (AFLP) analysis was used to determine the degree of intra- and inter-specific genetic variation in the genus Nicotiana. Forty-six lines of cultivated tobacco (Nicotiana tabacum L.) and seven wild Nicotiana species, including N. sylvestris, N. tomentosiformis, N. otophora, N. glutinosa, N. suaveolens, N. rustica, and N. longiflora, were analyzed, using at least eight different oligonucleotide primer combinations capable of detecting a minimum of 50 polymorphic bands per primer pair. The amount of genetic polymorphism present among cultivated tobacco lines (N. tabacum) was limited, as evidenced by the high degree of similarity in the AFLP profiles of cultivars collected worldwide. Six major clusters were found within cultivated tobacco that were primarily based upon geographic origin and manufacturing quality traits. A greater amount of genetic polymorphism exists among wild species of Nicotiana than among cultivated forms. Pairwise comparisons of the AFLP profiles of wild and cultivated Nicotiana species show that polymorphic bands present in N. tabacum can be found in at least one of three proposed wild progenitor species (i.e., N. sylvestris, N. tomentosiformis, and N. otophora). This observation provides additional support for these species contributing to the origin of N. tabacum.

A potent, nonpeptidyl 1H-quinolone antagonist for the gonadotropin-releasing hormone receptor

Extensive development of the structure-activity relationships of a screening lead determined three important pharmacophores for gonadotropin-releasing hormone (GnRH) receptor antagonist activity. Incorporation of the 3,4,5-trimethylphenyl group at the 3-position, 2-(2(S)-azetidinyl)ethoxy group at the 4-position, and N-4-pyrimidinylcarboxamide at the 6-position of the quinolone core resulted in the identification of 4-(2-(azetidin-2(S)-yl)ethoxy)-7-chloro-2-oxo-3-(3,4,5-trimethylphenyl)-1,2-dihydroquinoline-6-carboxylic acid pyrimidin-4-ylamide (1) as a potent antagonist of the GnRH receptor. A 10(4)-fold increase in in vitro binding affinity is observed for the GnRH receptor as compared to the initial screening lead. Compound 1 exhibits nanomolar binding activity and functional antagonism at the human receptor and is 7-fold less active at the rhesus receptor. Intravenous administration of compound 1 to rhesus monkeys results in a significant decrease of the serum levels of downstream hormones, luteinizing hormone (79% decrease in area under the curve) and testosterone (92% decrease in area under the curve), at a dose of 3 mg/kg. Quinolone 1 is a potent nonpeptidyl antagonist for the human GnRH receptor that is efficacious for the suppression of luteinizing hormone and testosterone in primates.

Quinolones as gonadotropin releasing hormone (GnRH) antagonists: simultaneous optimization of the C(3)-aryl and C(6)-substituents

A series of 3-arylquinolones was prepared and evaluated for their ability to act as gonadotropin releasing hormone (GnRH) antagonists. A variety of substitution patterns of the 3-aryl substituent are described. The 3,4,5-trimethylphenyl substituent (23h) was found to be optimal.

Potent antagonists of gonadotropin releasing hormone receptors derived from quinolone-6-carboxamides

SAR studies which focused upon the C-6 position of a recently described series of quinolone gonadotropin releasing hormone antagonists are reported. Synthetic access to diverse quinolone-6-carboxamides was achieved via the palladium-catalyzed amino-carbonylation reactions of iodide 4 with various amines. Amides related to 9y were especially potent, functional antagonists of rat and human GnRH receptors.

The physical location of genes cdc2 and prh1 in maize (Zea mays L.)

A biotin-labelling in situ hybridization technique was first used to physically map two single copy genes, cdc2 and prh1, in maize. These two genes are metabolically interrelated genes. The full-length cDNA clones cdc2ZmA and ZmPPI of genes cdc2 and prh1 were adopted as the probes. They are 1.3 and 1.6 kb in size, respectively. Clone cdc2ZmA was physically mapped on the long arm of chromosomes 4, 8, and 9. The percent distances from centromere to detection site were 57.9 +/- 2.7, 28.4 +/- 1.5, and 88.2 +/- 3.3. The detection rate was 19.2%. Clone ZmPPI was physically mapped on the long arm of chromosomes 4, 6, and 8. The percent distances were 53.6 +/- 1.2, 60.8 +/- 2.9 and 17.1 +/- 1.6. The detection ratio was 18.5%. The technique of chromosome ISH and the relationship between the location and function of these two genes have been discussed.

Effects of estradiol on the expression and production of IGFBP-2 by R3230AC mammary tumor cells

The R3230AC mammary adenocarcinoma of the Fischer rat possesses Type I and Type II IGF receptors. The mRNAs for IGFBP-2, -3, -4, -5 and -6 have been recently identified in this tumor in vivo and in vitro. Using western blotting techniques on tumor tissue homogenates or conditioned media, we demonstrated that IGFBP-2 and, to a lesser extent, IGFBP-3 were expressed, produced, and secreted by the R3230AC tumor cells. Moreover, immunohistochemical assessment of tumor sections with anti-IGFBP-2 demonstrated that signal for IGFBP-2 was localized in the neoplastic glandular epithelium and often in the lumina of the pseudoglandular structures characteristic of this neoplasm. Expression of IGFBP-2 is regulated by the estrogen status of the host. The significant increase occurring in tumors from ovariectomized hosts was completely reversed with hormone repletion. Both mRNA expression and production of IGFBP-2 in vitro were also regulatable by the presence of estradiol-17 beta, with both processes being inhibited by its addition to the cell culture medium. Thus, the response of IGFBP-2 to estrogen showed agreement both in vivo and in vitro, whereas progesterone had no significant effect on these parameters. In the R3230AC tumor, estrogen treatment in vivo decreases tumor growth. Therefore, a relationship could exist between the action of estradiol to inhibit production of IGFBP-2 and the ability of estrogens to regulate tumor growth.

Insulin-like growth factor-binding proteins in R3230AC mammary tumors of intact and diabetic rats

The insulin-responsive R3230AC mammary tumor possesses type I and type II insulin-like growth factor (IGF) receptors, and membrane preparations display affinity cross-linking of 125I-labeled IGF-I to IGF-binding proteins (IGFBPs). To identify the IGFBPs produced, Northern blotting analysis of poly(A)+ RNA extracts from tumor tissue was performed. Although transcripts of IGFBP-1 were not detected, intense bands were obtained at 1.7 and 6 kilobases (kb) when hybridized with radiolabeled IGFBP-2 and IGFBP-5 cDNA probes, respectively. A 2.6-kb band and a 2.4-kb weaker band were observed after hybridization with IGFBP-3 and IGFBP-4 probes, respectively. When IGFBP-6 cDNA was used, two bands were seen: a higher mol wt band at 6.3 kb and a smaller one at 1.3 kb. Tumors from streptozotocin-induced diabetic rats displayed an increase in the expression of IGFBP-2, and insulin treatment for 3 days normalized the IGFBP-2 mRNA levels. Tumors from diabetic rats displayed no change in IGFBP-3, -4, -5, and -6 mRNA levels from tumors of normoglycemic rats. However, tumors from insulin-treated rats showed significantly higher levels of mRNA for IGFBP-4 and IGFBP-5 than tumors from normoglycemic or diabetic rats. A similar, but less pronounced, pattern of changes in IGFBP-3 mRNA was seen, whereas levels of IGFBP-6 mRNA were unchanged throughout. To identify the cell type producing the mRNAs for these IGFBPs, in situ hybridization of tissue sections was used. Procedures were established that localized three of the five IGFBPs expressed in this tumor tissue. This technique showed that IGFBP-3 mRNA transcripts were observed mainly in endothelial cells of tumor vasculature, although they were also detected in stromal cells, IGFBP-4 was present mainly in tumor stroma cells, and IGFBP-5 mRNA was expressed predominantly in the epithelial cells of this tumor. Expression of IGFBP-5 mRNA transcripts was significantly diminished in primary and long term cultured R3230AC cells grown in alpha-Minimum Essential Medium and 10% fetal bovine serum. Tumors arising from injection of long term cultured cells that were injected into isologous rats contained high amounts of mRNA transcripts for IGFBP-5, suggesting the presence, in vivo, of positive regulators for the expression of this BP. Tumor cells cultured in the presence of insulin displayed a 2.2- to 2.5-fold increase in the expression of IGFBP-5. These findings imply a role for insulin as a regulator of the expression of IGFBP-5 in the R3230AC adenocarcinoma.