New insights into the ambivalent role of YAP/TAZ in human cancers

Hippo signaling was first identified in Drosophila as a key controller of organ size by regulating cell proliferation and anti-apoptosis. Subsequent studies have shown that this pathway is highly conserved in mammals, and its dysregulation is implicated in multiple events of cancer development and progression. Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) (hereafter YAP/TAZ) are the downstream effectors of the Hippo pathway. YAP/TAZ overexpression or activation is sufficient to induce tumor initiation and progression, as well as recurrence and therapeutic resistance. However, there is growing evidence that YAP/TAZ also exert a tumor-suppressive function in a context-dependent manner. Therefore, caution should be taken when targeting Hippo signaling in clinical trials in the future. In this review article, we will first give an overview of YAP/TAZ and their oncogenic roles in various cancers and then systematically summarize the tumor-suppressive functions of YAP/TAZ in different contexts. Based on these findings, we will further discuss the clinical implications of YAP/TAZ-based tumor targeted therapy and potential future directions.

Escape of U251 glioma cells from temozolomide-induced senescence was modulated by CDK1/survivin signaling

Temozolomide (TMZ) has been widely used in conjunction with radiotherapy for treating various types of cancers. However, tumor cells arrested in senescence due to TMZ administration can sometimes escape and become drug resistant. In the current study, the possible role of survivin in the senescence escape of TMZ-treated glioma cells was comprehensively studied. The levels of survivin and CDK1 expression in a human glioma cell line (U251) were monitored, and cell apoptosis, cell cycle distribution, anchorage-independent growth, and senescence were studied in U251 cells in different degrees of senescence. To further investigate how survivin affects the TMZ-resistance of gliomas, we modulated the levels of survivin and CKD1 expression in TMZ-treated cells and then examined how the treated cells responded. The results showed that knockdown of the survivin gene increased the sensitivity of glioma cells to TMZ treatment by inducing senescent cells to become apoptotic. Moreover, after senescence was induced, expression of the survivin gene became suppressed, but survivin levels returned to normal after the cells had escaped from senescence. While down-regulation of the survivin gene in senescent and senescence-escaping U251 cells had no effect on cell apoptosis, cell cycle distribution, or senescence status, it dramatically reduced the anchorage-independent growth ability of the cells. Additionally, CDK1 was able to not only enhance the anchorage-independent growth ability of the cells, but also contribute to their further senescence escape by modulating the survivin and other pathways. In conclusion, the survivin gene was necessary for glioma cells to escape from and enter into senescence during treatment with TMZ.

Epithelial-mesenchymal transition regulated by p38/MAPK signaling pathways participates in vasculogenic mimicry formation in SHG44 cells transfected with TGF-β cDNA loaded lentivirus in vitro and in vivo

TGF-β-induced epithelial-mesenchymal transition (EMT) plays an important role in tumor progression. We assessed whether the TGF-β-induced EMT contributed to vasculogenic mimicry (VM) formation in glioma, we established an SHG44 cell line stably transfected with TGF-β cDNA loaded lentivirus. SB203580 was employed to inhibit the TGF-β-induced EMT. The results showed that the VM forming ability of cells could be improved by TGF-β over-expression. The migration and invasion capabilities of cells were also enhanced due to EMT. SB203580 was able to weaken cell migration, invasion and VM forming abilities via blocking p38/MAPK signaling pathways, but it had tiny influence on MMP/LAMC2 chain. Consequently, we concluded that EMT inhibition via p38/MAPK signaling pathways would partly impair TGF-β-induced VM formation in glioma.

Injury biomechanics, neuropathology, and simplified physics of explosive blast and impact mild traumatic brain injury

Explosive blast shock waves and blunt impact to the head are two types of loading shown to result in mild traumatic brain injury (mTBI). While mTBI from these two causes shares some common features behaviorally, there are distinct differences in the pathophysiology of the underlying injury mechanisms. Various elucidations have been offered in the literature to explain the organic damage associated with mTBI resulting from both types of loading. The current state of understanding in this field is somewhat limited by the degree of appreciation of the physics and biomechanics governing the effects of explosive blast shock waves and blunt impact on the head, which has resulted in the various approaches to the investigation of the operative brain injury "wounding mechanisms". In this chapter we provide a simplified description of terminology associated with forces on the head from explosive blast shock waves and blunt impact, to assist readers in the field in evaluating interpretations of brain injury "wounding" processes. Remarkably, mTBI from either loading is shown generally to result in only a small loss of neurons, with hippocampal neurons appearing to be particularly vulnerable to explosive blast shock waves. Explosive blast studies in large animal models show a unique pattern of periventricular injury, which is different from the classic diffuse axonal injury. Both astrocyte and microglial activation are also seen in explosive blast as well as impact trauma, but this may be a general secondary brain injury response, nonspecific to explosive blast or blunt trauma. Additionally, while moderate to severe impact closed head injuries sometimes result in petechial hemorrhages or hematomas, they do not appear to be associated with explosive blast mTBI even with repeated exposure to blasts.

Brain injury from explosive blast: description and clinical management

Accumulating clinical experience is indicating that explosive blast brain injury is becoming recognized as a disease distinct from the penetrating form of blast injury as well as the classic closed head injury (CHI). In recent US conflicts in Iraq and Afghanistan, over 60% of combat casualties were from explosive blast with the hallmark explosive weapon being the improvised explosive device (IED). Explosive blast TBI is a condition afflicting many combat injured warfighters potentially constituting another category of TBI. Clinically, it shares many features with conventional TBI but possesses some unique aspects. In its mild form, it also shares many clinical features with PTSD but here again has distinct aspects. Although military medical providers depend on civilian standard of care guidelines when managing explosive blast mTBI, they are continually adapting their medical practice in order to optimize the treatment of this disease, particularly in a theater of war. It is clear that further rigorous scientific study of explosive blast mTBI at both the basic science and clinical levels is needed. This research must include improved understanding of the causes and mechanisms of explosive blast TBI as well as comprehensive epidemiologic studies to determine the prevalence of this disease and its risk factors. A widely accepted unambiguous clinical description of explosive blast mTBI with diagnostic criteria would greatly improve diagnosis. It is hoped that through appropriate research meaningful prevention, mitigation, and treatment strategies for explosive blast mTBI can be speedily realized.

Advances in imaging explosive blast mild traumatic brain injury

In the past, direct physical evidence of mild traumatic brain injury (mTBI) from explosive blast has been difficult to obtain through conventional imaging modalities such as T1- and T2-weighted magnetic resonance imaging (MRI) and computed tomography (CT). Here, we review current progress in detecting evidence of brain injury from explosive blast using advanced imaging, including diffusion tensor imaging (DTI), functional MRI (fMRI), and the metabolic imaging methods such as positron emission tomography (PET) and magnetic resonance spectroscopic imaging (MRSI), where each targets different aspects of the pathology involved in mTBI. DTI provides a highly sensitive measure to detect primary changes in the microstructure of white matter tracts. fMRI enables the measurement of changes in brain activity in response to different stimuli or tasks. Remarkably, all three of these paradigms have found significant success in conventional mTBI where conventional clinical imaging frequently fails to provide definitive differences. Additionally, although used less frequently for conventional mTBI, PET has the potential to characterize a variety of neurotransmitter systems using target agents and will undoubtedly play a larger role, once the basic mechanisms of injury are better understood and techniques to identify the injury are more common. Finally, our MRSI imaging studies, although acquired at much lower spatial resolution, have demonstrated selectivity to different metabolic and physiologic processes, uncovering some of the most profound differences on an individual by individual basis, suggesting the potential for utility in the management of individual patients.

Transforming growth factor-β is required for vasculogenic mimicry formation in glioma cell line U251MG

Both vasculogenic mimicry (VM) and transforming growth factor-β (TGFβ) are positively correlated with malignancy in glioma. Accordingly, we supposed that TGFβ might be related with VM, and aimed to detect whether TGFβ could influence VM formation in two glioma cell lines U251MG and SHG44, which were different in malignancy. We found that the VM-positive U251MG had a significantly higher TGFβ expression than the VM-negative SHG44. Downregulating TGFβ in U251MG by RNAi technology resulted in a significantly impaired VM formation, which could be rescued by rhTGFβ. However, adding rhTGFβ could not induce VM in SHG44. To investigate the possible mechanism, we detected the changes of some VM-related genes including EphA2, VE-cadherin, MMP-2, MMP-9, MT1-MMP and LAMC2 by RT-PCR and found that MT1-MMP transcript was affected by TGFβ expression. Gelatin zymography showed a declined MMP-2 activity in the TGFβ-inhibited cells. Further studies showed that MT1-MMP inhibition impaired VM formation in U251MG. Moreover, TGFβ induced MT1-MMP expression and VM formation in a dose-dependent manner. These findings indicated us that TGFβ was required for VM formation in U251MG. MT1-MMP was correlated with TGFβ-induced VM formation. Thus, TGFβ might be a potential target for VM inhibition in glioma.

Nrf2-regulated glutathione recycling independent of biosynthesis is critical for cell survival during oxidative stress

Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) is the primary transcription factor protecting cells from oxidative stress by regulating cytoprotective genes, including the antioxidant glutathione (GSH) pathway. GSH maintains cellular redox status and affects redox signaling, cell proliferation, and death. GSH homeostasis is regulated by de novo synthesis as well as GSH redox state; previous studies have demonstrated that Nrf2 regulates GSH homeostasis by affecting de novo synthesis. We report that Nrf2 modulates the GSH redox state by regulating glutathione reductase (GSR). In response to oxidants, lungs and embryonic fibroblasts (MEFs) from Nrf2-deficient (Nrf2(-/-)) mice showed lower levels of GSR mRNA, protein, and enzyme activity relative to wild type (Nrf2(+/+)). Nrf2(-/-) MEFs exhibited greater accumulation of glutathione disulfide and cytotoxicity compared to Nrf2(+/+) MEFs in response to t-butylhydroquinone, which was rescued by restoring GSR. Microinjection of glutathione disulfide induced greater apoptosis in Nrf2(-/-) MEFs compared to Nrf2(+/+) MEFs. In silico promoter analysis of the GSR gene revealed three putative antioxidant-response elements (ARE1, -44; ARE2, -813; ARE3, -1041). Reporter analysis, site-directed mutagenesis, and chromatin immunoprecipitation assays demonstrated binding of Nrf2 to two AREs distal to the transcription start site. Overall, Nrf2 is critical for maintaining the GSH redox state via transcriptional regulation of GSR and protecting cells against oxidative stress.

HLA-A, -B, -C, -DRB1 allele and haplotype frequencies in an African American population

Sequence-based typing was used to identify human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 alleles from 564 consecutively recruited African American volunteers for an unrelated hematopoietic stem cell registry. The number of known alleles identified at each locus was 42 for HLA-A, HLA-B 67, HLA-C 33, and HLA-DRB1 44. Six novel alleles (A*260104, A*7411, Cw*0813, Cw*1608, Cw*1704, and DRB1*130502) not observed in the initial sequence-specific oligonucleotide probe testing were characterized. The action of balancing selection, shaping more 'even' than expected allele frequency distributions, was inferred for all four loci and significantly so for the HLA-A and DRB1 loci. Two-, three-, and four-locus haplotypes were estimated using the expectation maximization algorithm. Comparisons with other populations from Africa and Europe suggest that the degree of European admixture in the African American population described here is lower than that in other African American populations previously reported, although HLA-A:B haplotype frequencies similar to those in previous studies of African American individuals were also noted.

Strategies for evaluating B*18 allelic diversity by sequence-based typing applied to studies of a population from Singapore and African-Americans

Strategies to resolve B*18 alleles which carry a deletion in intron 1 close to the 5' end of exon 2 relative to other HLA-B alleles or a null allele mutation in exon 1 and to resolve ambiguities among allele combinations including B*18 are described. B*18 allele frequencies from volunteer donors recruited for two hematopoietic stem cell registries show the presence of two alleles, B*180101 and B*1802, in a population from Singapore and only B*180101 in African-Americans.

Exclusion of galectin 9 as a candidate gene for hyperuricosuria in the Dalmatian dog

All Dalmatian dogs have an inherited defect in purine metabolism leading to high levels of uric acid excretion in their urine (hyperuricosuria) rather than allantoin, the normal end product of purine metabolism in all other breeds of dog. Transplantation experiments have demonstrated that the defect is intrinsic to the liver and not the kidney. Uricase, the enzyme involved in the breakdown of urate into allantoin, has been shown to function in Dalmatian liver cells. Therefore, candidate genes for this defect include transporters of urate, a salt of uric acid, across cell membranes. We excluded one such urate transporter candidate, galectin 9, using a Dalmatian x Pointer backcross in which hyperuricosuria was segregating.

Treatment with the snail peptide CGX-1007 reduces DNA damage and alters gene expression of c-fos and bcl-2 following focal ischemic brain injury in rats

Delayed cell death following ischemic brain injury has been linked to alterations in gene expression. In this study we have evaluated the upregulation of several genes associated with delayed cell death (c-fos, bax, and bcl-2) during the initial 24 h of transient middle cerebral artery occlusion (MCAo) in the rat and the effects of postinjury treatment with the NR2B subunit specific NMDA receptor antagonist CGX-1007 (Conantokin-G, Con-G). C-fos mRNA levels peaked at 1 h postinjury in both cortical and subcortical ischemic brain regions (30-fold increase), remained elevated at 4 h and returned to within normal, preinjury levels 24 h postinjury. The increase in mRNA levels correlated to increased protein expression in the entire ipsilateral hemisphere at 1 h. Regions of necrosis at 4 h were void of C-Fos immunoreactivity with continued upregulation in surrounding regions. At 24 h, loss of C-Fos staining was observed in the injured hemisphere except for sustained increases along the border of the infarct and in the cingulate cortex of vehicle treated rats. CGX-1007 treatment reduced c-fos expression throughout the infarct region by up to 50%. No significant differences were measured in either bcl-2 or bax mRNA expression between treatment groups. However, at 24 h postinjury CGX-1007 treatment was associated with an increase in Bcl-2 immunoreactivity that correlated to a reduction in DNA fragmentation. In conclusion, CGX-1007 effectively attenuated gene expression associated with delayed cell death as related to a neuroprotective relief of cerebral ischemia.

Activation of the NPTA element of the CYP2A3 gene by NFI-A2, a nasal mucosa-selective nuclear factor 1 isoform

The aim of this study was to determine whether the NPTA element of the olfactory mucosa-predominant CYP2A3 gene can be activated by NFI-A2, a recently identified member of the nuclear factor 1 family of transcription factors. Isoform-specific RNA-PCR confirmed that NFI-A2 is mainly expressed in rat olfactory mucosa. A full-length NFI-A2 cDNA was isolated from a cDNA library of rat olfactory mucosa and was used for preparation of a construct encoding a fusion protein of NFI-A2 with the yeast GAL4 activation domain. Expression of the fusion protein in yeast was detected with an antibody to NFI-A. The fusion protein activated the expression of a LacZ reporter gene in yeast one-hybrid assays with a reporter construct containing the NPTA element, but not with other constructs lacking the NPTA element. These findings suggest that NFI-A2 may be involved in the tissue-selective transcriptional activation of the CYP2A3 gene in the olfactory mucosa.

PATCHED and p53 gene alterations in sporadic and hereditary basal cell cancer

It is widely accepted that disruption of the hedgehog-patched pathway is a key event in development of basal cell cancer. In addition to patched gene alterations, p53 gene mutations are also frequent in basal cell cancer. We determined loss of heterozygosity in the patched and p53 loci as well as sequencing the p53 gene in tumors both from sporadic and hereditary cases. A total of 70 microdissected samples from tumor and adjacent skin were subjected to PCR followed by fragment analysis and DNA sequencing. We found allelic loss in the patched locus in 6/8 sporadic basal cell cancer and 17/19 hereditary tumors. All sporadic and 7/20 hereditary tumors showed p53 gene mutations. Loss of heterozygosity in the p53 locus was rare in both groups. The p53 mutations detected in hereditary tumors included rare single nucleotide deletions and unusual double-base substitutions compared to the typical ultraviolet light induced missense mutations found in sporadic tumors. Careful microdissection of individual tumors revealed genetically linked subclones with different p53 and/or patched genotype providing an insight on time sequence of genetic events. The high frequency and co-existence of genetic alterations in the patched and p53 genes suggest that both these genes are important in the development of basal cell cancer.

Utility of routine serial computed tomography for blunt intracranial injury

BACKGROUND

To determine the utility of routine serial head computed tomography (H-CT) for predicting need for invasive neurosurgical intervention in patients with blunt intracranial injuries (BICI).

METHODS

Patients treated at a Level I trauma center with BICI over a 4-year period were reviewed.

RESULTS

Of the 4,273 blunt trauma patients evaluated, 9.7% (415/4,273) were diagnosed as having BICI. Invasive intervention (craniotomy, ICP monitoring, ventriculostomy, or angiogram) was performed in 41.2% (171/415) of patients with BICI. Of these, 94.7% (162/171) had the procedure performed as a result of the initial H-CT. The remaining 5.3% (9/171) had the intervention performed as a result of a subsequent H-CT. Serial H-CT documented worsening of BICI in 32.3% (64/198) of the patients, but only those who had significant corresponding clinical deterioration had an invasive procedure as a result.

CONCLUSION

In patients with an unchanged or normal neurologic exam, a routine serial H-CT did not influence subsequent invasive neurosurgical intervention.

Persistent p53 mutations in single cells from normal human skin

Epidermal clones of p53-mutated keratinocytes are abundant in chronically sun-exposed skin and may play an important role in early development of skin cancer. Advanced laser capture microdissection enables genetic analysis of targeted cells from tissue sections without contamination from neighboring cells. In this study p53 gene mutations were characterized in single cells from normal, chronically sun-exposed skin. Biopsies were obtained from skin subjected to daily summer sun and skin totally protected from the sun by blue denim fabric. Using laser capture microdissection, 172 single-cell samples were retrieved from four biopsies and analyzed using single-cell polymerase chain reaction and direct DNA sequencing. A total of 14 different mutations were identified in 26 of 99 keratinocytes from which the p53 gene could be amplified. Mutations displayed a typical UV signature and were detected in both scattered keratinocytes and in a small cluster of p53-immunoreactive keratinocytes. This minute epidermal p53 clone had a diameter of 10 to 15 basal cells. Two missense mutations were found in all layers of epidermis within the p53 clone. The presented data show that p53 mutations are common in normal skin and that a clone of keratinocytes with a mutated p53 gene prevailed despite 2 months of total protection from ultraviolet light.

Epidermal p53 response and repair of thymine dimers in human skin after a single dose of ultraviolet radiation: effects of photoprotection

A cellular p53 response, DNA repair enzymes and melanin pigmentation are important strategies utilized by skin keratinocytes against impairment caused by ultraviolet radiation (UVR). In this study a double-immunofluorescence technique was used to investigate UVR-induced thymine dimers and p53 protein simultaneously. Four healthy volunteers were irradiated on both sides of their buttock skin with a single dose of solar-simulating UVR. One side was pretreated with a topical sunscreen. Biopsies from different time-points were immunostained for visualization of thymine dimers, p53 and proliferation. One single physiological dose of UVR generated widespread formation of thymine dimers throughout the epidermis 4h after irradiation. The level of thymine dimers decreased over time and was followed by a p53 response in the same cells. A late proliferative response was also found. The formation of thymine dimers, the p53 response and the late proliferative response were partially blocked by topical sunscreen. Large inter-individual differences in the kinetics of thymine dimer formation and repair as well as in the p53 response were evident in both sunscreen-protected and unprotected skin.

Rituximab using a thrice weekly dosing schedule in B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity

PURPOSE

Rituximab has been reported to have little activity in small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL) and to be associated with significant infusion-related toxicity. This study sought to decrease the initial toxicity and optimize the pharmacokinetics with an alternative treatment schedule.

PATIENTS AND METHODS

Thirty three patients with SLL/CLL received dose 1 of rituximab (100 mg) over 4 hours. In cohort I (n = 3; 250 mg/m(2)) and cohort II (n = 7; 375 mg/m(2)) rituximab was administered on day 3 and thereafter three times weekly for 4 weeks using a standard administration schedule. Cohort III (n = 23; 375 mg/m(2)) administered rituximab similar to cohort II for the first two treatments and then over 1 hour thereafter.

RESULTS

A total of 33 CLL/SLL patients were enrolled; only one patient discontinued therapy because of infusion-related toxicity. Thirteen patients developed transient hypoxemia, hypotension, or dyspnea that were associated with significant changes in baseline interleukin-6, interleukin-8, tumor necrosis factor alpha, and interferon gamma compared with those not experiencing such reactions. Infusion-related toxicity occurred more commonly in older (median age 73 v 62 years; P =.02) patients with no other pretreatment clinical or laboratory features predicting occurrence of these events. The overall response rate was 45% (3% CR, 42% PR; 95% CI 28% to 64%). Median response duration for these 15 patients was 10 months (95% CI, 6.8-13.2; range, 3 to 17+).

CONCLUSION

Rituximab administered thrice weekly for 4 weeks demonstrates clinical efficacy and acceptable toxicity. Initial infusion-related events seem to be cytokine mediated and resolve by the third infusion making rapid administration possible. Future combination studies of rituximab with other therapies in CLL seem warranted.

Analysis of p53 mutations in single cells obtained from histological tissue sections

We have previously reported on direct sequence analysis of the p53 gene in laser-dissected single cells from tissue sections, where each allele of two fragments (exons 7 and 8) could be accurately analyzed in only 14% of the cells due to the high frequency of exon and allele dropout. Here in an effort to minimize this problem, we have investigated various approaches for sample preparation and gene amplification. By pinpointing some critical steps in the procedure, we could increase the number of investigated exons and substantially improve the genetic analysis of single cells obtained from histochemically stained frozen tissue sections. The biggest improvement was achieved by minimizing DNA degradation using EDTA as a nuclease inhibitor in all sample preparation steps. Efforts to increase primer annealing, by increasing the concentration of template and primers, in addition to prolonging the annealing and extension times, also improved the amplification efficiency. With these measures we can now amplify six individual exons of the p53 gene (exons 4-9) in 70% of the cells and in 50% of these cells both alleles are amplified. This allows application of the method in various investigations such as within the field of tumor pathology.

[The study of beta-fibrinogen gene - 455 G/A, - 148 C/T, 448 G/A polymorphisms and their association with plasma fibrinogen levels]

OBJECTIVE

To analyze the frequency of beta-fibrinogen (beta-Fg) gene - 455 G/A, - 148 C/T, 448 G/A polymorphisms and their association with plasma fibrinogen levels in Han nationality in Guangdong Chinese.

METHODS

The beta-Fg gene - 455 G/A, - 148 C/T, 448 G/A polymorphisms of 156 individuals were analyzed by restriction fragment length polymorphism (RFLP). Plasma fibrinogen levels were determined by turbidimetry.

RESULTS

The frequencies of A(- 455), T(- 148) and A(448) allele were 0.276, 0.285 and 0.272, respectively. There were strong linkages of G(- 455), C(- 148) and G(448), and of A(- 455), T(- 148) and A(448), the correspondence was more than 97%. The plasma fibrinogen levels in the presence and absence of A(- 455) allele were (3.13 +/- 0.74) g/L and (2.89 +/- 0.57) g/L (P < 0.05); of T(- 148) allele were (3.12 +/- 0.73) g/L and (2.89 +/- 0.58) g/L (P < 0.05); and of A(448) were (3.13 +/- 0.74) g/L and (2.89 +/- 0.57) g/L (P < 0.05), respectively. The plasma fibrinogen levels of the three polymorphisms with the mutant gene are significantly higher than that in the wild type.

CONCLUSION

The three polymorphisms loci are strong linkage disequilibrium. It suggests that beta-Fg gene - 455 G/A, - 148 C/T, 448 G/A polymorphisms are associated with plasma fibrinogen levels.

Evidence of commonality between canine and human extraintestinal pathogenic Escherichia coli strains that express papG allele III

Although dogs have been proposed as carriers of extraintestinal pathogenic Escherichia coli (ExPEC) with infectious potential for humans, presumed host species-specific differences between canine and human ExPEC strains have cast doubt on this hypothesis. The recent discovery that allele III of papG (the P fimbrial adhesin gene) predominates among human cystitis isolates and confers an adherence phenotype resembling that of canine ExPEC prompted the present reevaluation of the canine-human ExPEC connection. Sixteen paired pap-positive urine and rectal E. coli isolates from dogs with urinary tract infection were studied. papG (adhesin) and papA (pilin) allele type, agglutination phenotypes, virulence factor genotypes, and randomly amplified polymorphic DNA and pulsed-field gel electrophoresis fingerprints were analyzed and compared with those of human ExPEC controls. The 16 canine strains contained predominantly papG allele III. Agglutination phenotypes segregated strictly according to papG allele status and were homogeneous among strains with the same papG allele profile irrespective of their human versus canine origin. Canine and human PapG variant III peptide sequences were highly homologous, without host species-specific differences. The most prevalent canine papA allele was F48, a novel variant recently identified among human urosepsis isolates. In addition to pap, human ExPEC-associated virulence genes detected among the canine strains included sfa/focDE, sfaS, fyuA, hlyA, cnf1, cdtB, kpsMT-II and -III, rfc, traT, ompT, and a marker for a pathogenicity-associated island from archetypal human ExPEC strain CFT073. Molecular fingerprinting confirmed the fecal origin of all but one canine urine isolate and showed one pair of O6 canine urine and fecal isolates to be extremely similar to an O6 human urosepsis isolate with which they shared all other genotypic and phenotypic characteristics analyzed. These data demonstrate that canine ExPEC strains are similar to, and in some instances essentially indistinguishable from, human ExPEC strains, which implicates dogs and their feces as potential reservoirs of E. coli with infectious potential for humans.

Induced hypothermia during emergency department thoracotomy: an animal model

BACKGROUND

Induced hypothermia is used clinically to prevent ischemic injury during elective procedures. We present an animal model of asanguinous hypothermic (10 degrees C) circulatory arrest, induced through a left anterior lateral thoracotomy after exsanguinating uncontrolled hemorrhage.

METHODS

Through a left anterior thoracotomy, 26 swine (45-70 kg) sustained a laceration of the descending thoracic aorta, producing exsanguinating uncontrolled hemorrhage. After 5 minutes of severe hypotension (systolic BP <20 mm Hg), a 22 French Foley catheter was directed cephalad through the enlarged aortic wound. A solution (containing 42.5 mmol/L K+ and precooled to 1 degrees C) was infused to arrest/preserve the heart and brain. A second 24 French Foley catheter was then directed caudally through the same wound. The right atrium was opened to drain the venous system. The animal was cooled with a cardiopulmonary bypass pump (>5L/min) through the Foley catheters. Once 10 degree C was reached, a cannula was placed to the aortic root and the aortic laceration repaired. The animal was maintained at 10 degree C for a total of 90 minutes. Before the rewarming process, the circulation was rinsed with a solution containing normal levels of electrolytes followed by infusion of whole blood. Rewarming was performed by maintaining a 10-degree gradient on the heat exchanger. The first 16 animals were used in nonsurvival experiments to develop the technique and to record dural temperatures and electroencephalogram tracings. The last 10 animals were used to determine long-term survival and neurologic outcome. Group I: seven animals were kept at < 10 degrees C with flows less than 2L/min. Group II: three animals underwent 20, 30, and 40 minutes of no flow once they were cooled to 10 degrees C. After 6 weeks of survival and neurologic examinations, the brains were fixed for histologic evaluations.

RESULTS

The average time to cool the head to 18 degrees C and 10 degrees C was 6 minutes and 12 minutes, respectively. The hematocrit fell below 2% by the end of the cooling period. A total of 7 of the 10 animals from the long-term study survived. Group I: five of seven animals survived. Four of the survivors had no appreciable neurologic deficits, were fully functional at 6 weeks, and had no evidence of histologic injury. One of the five survivors in this group had moderate neurologic disability. Of the two animals that died, one died from air embolism from the i.v. line. The second death was in an animal for which maximal cooling to 2.7 degrees C was attempted. Group II: The first two animals that had "no flow" for 20 and 30 minutes were fully functional and had normal neurologic examinations. However, the second animal was found to have brain injury on histologic examination. The last animal in this group died of accidental extubation during recovery.

CONCLUSION

Induction of hypothermic arrest through the chest after exsanguination is possible. The further development of this technique may provide an extended state of "suspended animation" to allow for repairs of hemorrhaging injuries in trauma patients who require emergency department thoracotomy.

Human neutrophil activation and increased adhesion by various resuscitation fluids

OBJECTIVE

To determine whether activated neutrophils play a major role in secondary tissue injury after resuscitation in trauma. We hypothesized that human neutrophil activation and adhesion vary, depending on the type and amount of resuscitation fluid used.

SETTING

University-based research facility.

SUBJECTS

Ten healthy adult volunteers.

DESIGN

Whole blood from volunteers was serially diluted in polypropylene tubes with various resuscitation fluids. Fluids tested were phosphate-buffered saline, normal saline, lactated Ringer's solution, dextran, hespan, 5% human albumin, 25% human albumin, 3.5% hypertonic saline, and 7.5% hypertonic saline. Neutrophil activation (intracellular oxidative burst activity with dichlorofluorescin diacetate staining) and adhesion (integrin cell surface expression of CD18) were measured with flow cytometry (fluorescence-activated cell sorting). Blood was diluted with hypertonic saline by controlling for sodium content equal to normal saline. dose-related increase in neutrophil oxidative burst activity as the result of dilution followed with crystalloid fluids and artificial colloids (dextran and hespan). The increase was 12-18 x baseline at the 75% dilution. The increase with 5% human albumin was only 2.2 x baseline, and 25% albumin did not demonstrate any increased intracellular activity. A similar significant increase in the neutrophil adhesion expression (CD18) occurred with artificial colloids (p<.05) and, to a lesser extent, with crystalloids, but not with albumin. Hypertonic saline caused a decrease in CD18 cell surface expression.

CONCLUSIONS

This study suggests that the neutrophil activation and adhesion may vary, depending on the type of resuscitative fluid used. All artificial resuscitative fluids may not be similar or innocuous, as demonstrated by the dose-related increase in neutrophil activation and adhesion.

A comprehensive guide for the recognition and classification of distinct stages of hair follicle morphogenesis

Numerous spontaneous and experimentally induced mouse mutations develop a hair phenotype, which is often associated with more or less discrete abnormalities in hair follicle development. In order to recognize these, it is critically important to be able to determine and to classify accurately the major stages of normal murine hair follicle morphogenesis. As an aid, we propose a pragmatic and comprehensive guide, modified after previous suggestions by Hardy, and provide a list of easily recognizable classification criteria, illustrated by representative micrographs. Basic and more advanced criteria are distinguished, the former being applicable to all mouse strains and requiring only simple histologic stains (hematoxylin and eosin, Giemsa, periodic acid Schiff, alkaline phosphatase activity), the latter serving as auxiliary criteria, which require a pigmented mouse strain (like C57BL/6J) or immunohistochemistry (interleukin-1 receptor type I, transforming growth factor-beta receptor type II). In addition, we present simplified, computer-generated schematic drawings for the standardized recording and reporting of gene and antigen expression patterns during hair follicle development. This classification aid serves as a basic introduction into the field of hair follicle morphogenesis, aims at standardizing the presentation of related hair research data, and should become a useful tool when screening new mouse mutants for discrete abnormalities of hair follicle morphogenesis (compared with the respective wild type) in a highly reproducible, easily applicable, and quantifiable manner.

[Detection of apoptosis exposed to 10-hydroxycamptothecin in T24 human urinary bladder cancer cells]

OBJECTIVE

To study whether 10-hydroxycamptothecin (HPT) can induce apoptosis in bladder cancer cell and establish methods for detecting apoptotic cells.

METHODS

Human urinary bladder cancer cell line (T24) was exposed in vitro to different concentrations of 10-hydroxycamptothein for various lengths of time. Flow cytometry, Hochest 33258 and Hematoxylin staining were used to determine the induction of apoptosis after use of HPT. DNA gel analysis was also carried out to detect DNA fragmentation.

RESULTS

Cell shrinage, nuclear fragmentation and condensed chromosomes showed that apoptosis can be induced by HPT within the concentration of 0.01 - 10 microg/ml. The flow cytometry analysis showed that the percentage of apoptotic cells were related to the concentration and the time of induction. T24 cell line exposed to HPT experienced internucleosomal DNA fragmentation by producing a typical ladder pattern on agarose gel electrophoresis. The detection of minimum exposure time for HPT-induced apoptosis in T24 cells showed that 3 hours of exposure to HPT were enough to trigger internucleosomal DNA fragmentation. Compared to Hochest 33258 staining, Hematoxylin staining was more easy, rapid and accurate to detect apoptosis.

CONCLUSIONS

The induction of apoptosis exposed to HPT in T24 human urinary bladder cancer cells is a good model for further studying urinary bladder cancer. Hematoxylin staining is a useful method for detecting apoptosis.

Clones of normal keratinocytes and a variety of simultaneously present epidermal neoplastic lesions contain a multitude of p53 gene mutations in a xeroderma pigmentosum patient

A patient with xeroderma pigmentosum group C was extensively examined for mutations in the p53 gene in normal skin exposed to varying degrees of sunlight and in excisional biopsies of basal cell cancer, squamous cell cancer, and squamous cell dysplasia. Seventy-three samples were analyzed by microdissection of small cell clusters, followed by PCR and direct DNA sequencing. In skin taken from areas that most likely had never been exposed to the sun, no mutations were found. However, in skin exposed to the sun, we observed a multitude of mutations in the p53 gene. UV light-induced mutations were found in all types of lesions, as well as in clusters of morphologically normal epidermal cells. Twenty-nine distinct mutations were found in exons 5-8, all missense or nonsense, of which 27 (93%) were UV-specific C --> T or CC --> TT transitions at dipyrimidine sites of the nontranscribed strand. Two types of normal skin areas containing p53 mutations were observed: areas that stain strongly with p53 antibody (p53 patches) and those that do not stain. Because no silent or intron mutations were found in these cell clusters, the alterations in the p53 gene of morphologically normal cells are likely to have resulted in a selective growth advantage. The poor correlation between mutations and morphological phenotypes demonstrates that p53 mutations alone do not determine the phenotypes observed.

[Rapid determination of creatinine in urine by capillary electrophoresis in a multiple injection mode]

The level of urinary creatinine in clinic diagnosis is one of the useful index of renal function, and is often used as a reference of some biochemical substance determined in random urine. In this paper, a rapid multiple-injection capillary electrophoresis(CE) method for the determination of urinary creatinine is reported. A 36 cm x 50 microns coated capillary, a phosphoric acid buffer(0.1 mol/L, pH 2.5)and UV-detector at 200 nm wavelength were used in this method. In comparing with single injection for five samples, the analysis time of five successive injections can save 20 min. By use of pyridine as internal standard, the correlation between the concentrations of creatinine and the corresponding peak height ratios of creatinine and pyridine is good(r = 0.9996), and the assay precision is acceptable. We also compared the CE method with the bio-analyser(Jeffe' kinetic), and the results showed a satisfactory correlation (r = 0.9773, n = 12) and a shorter analysis time.

Lactated Ringer's solution resuscitation causes neutrophil activation after hemorrhagic shock

PURPOSE

To determine the degree of neutrophil activation caused by hemorrhagic shock and resuscitation.

METHODS

Awake swine underwent 15-minute 40% blood volume hemorrhage, and a 1-hour shock period, followed by resuscitation with: group I, lactated Ringer's solution (LR); group II, shed blood; and group III, 7.5% hypertonic saline (HTS). Group IV underwent sham hemorrhage and LR infusion. Neutrophil activation was measured in whole blood using flow cytometry to detect intracellular superoxide burst activity.

RESULTS

Neutrophil activation increased significantly immediately after hemorrhage, but it was greatest after resuscitation with LR (group I, 273 vs. 102%; p < 0.05). Animals that received shed blood (group II) and HTS (group III) had neutrophil activity return to baseline state after resuscitation. Group IV animals had an increase in neutrophil activation (259 vs. 129%; p < 0.05).

CONCLUSION

Neutrophil activation occurring after LR resuscitation and LR infusion without hemorrhage, but not after resuscitation with shed blood or HTS, suggests that the neutrophil activation may be caused by LR and not by reperfusion.

Analysis of apoptosis during hair follicle regression (catagen)

Keratinocyte apoptosis is a central element in the regulation of hair follicle regression (catagen), yet the exact location and the control of follicular keratinocyte apoptosis remain obscure. To generate an "apoptomap" of the hair follicle, we have studied selected apoptosis-associated parameters in the C57BL/6 mouse model for hair research during normal and pharmacologically manipulated, pathological catagen development. As assessed by terminal deoxynucleotide transferase dUTP fluorescein nick end-labeling (TUNEL) stain, apoptotic cells not only appeared in the regressing proximal follicle epithelium but, surprisingly, were also seen in the central inner root sheath, in the bulge/isthmus region, and in the secondary germ, but never in the dermal papilla. These apoptosis hot spots during catagen development correlated largely with a down-regulation of the Bcl-2/Bax ratio but only poorly with the expression patterns of interleukin-1beta converting enzyme, p55TNFR, and Fas/Apo-1 immunoreactivity. Instead, a higher correlation was found with p75NTR expression. During cyclophosphamide-induced follicle dystrophy and alopecia, massive keratinocyte apoptosis occurred in the entire proximal hair bulb, except in the dermal papilla, despite a strong up-regulation of Bax and p75NTR immunoreactivity. Selected receptors of the tumor necrosis factor/nerve growth factor family and members of the Bcl-2 family may also play a key role in the control of follicular keratinocyte apoptosis in situ.

[Apoptosis of nasopharyngeal carcinoma cells induced by topoisomerase I inhibitor]

PURPOSE

To determine if the topoisomerase I inhibitor Camptothecin (CPT) can induce apoptosis in vitro in a human nasopharyngeal carcinoma (NPC) cell line with low differentiation (CNE-2Z).

METHODS

The light microscopy, flow cytometry and agarose gel electrophoresis were used to examine the morphological changes, cell cycle distribution, hypodiploid cells and DNA fragmentation.

RESULTS

After exposure to CPT for a certain period, CNE-2Z cells underwent obvious morphological changes with characteristics of apoptosis such as decrease in cell volumes condensation of chromatin and the formation of apoptotic bodies. Flow cytometry (FCM) test showed that when CNE-2Z cells were treated with 2-10 mumol/L CPT for 12 or 24 hours, hypodiploid cells accounted for 30% and 50% respectively. Cell cycle analysis by FCM revealed that changes in CNE-2Z cell cycle distribution were apparent 24 hours after treatment with various doses of CPT, showing no obvious dose-dependent relationship. Compared with controls, the percentage of cells in G2/M phase decreased markedly while those in G1 and S phases increased moderately.

CONCLUSION

The results demonstrated that DNA topoisomerase I inhibitor Camptothecin can induce apoptosis in CNE-2Z cells in vitro.

[Determination of human urinary pseudouridine by high performance capillary electrophoresis]

Pseudouridine, mainly as a degradation product of transfer ribonucleic acid, has been shown to be excreted in abnormal amounts in the urine of patients with cancer and can be used as one of the potentially valuable tumor markers. In this paper, a method for the rapid determination of human urinary pseudouridine by HPCE is reported. We used a 24 cm x 25 microm i.d. coated capillary and a borate buffer solution (0.1 mol/L, pH 8.6), and set the UV detection wavelength at 200 nm. In this experiment, pseudouridine can be separated completely with uridine and anti-tumor drugs (5-fluouridine and methetrexation) and other endogenous substances in urine within 4 minutes. Assay precision was determined for concentrations of 50 micromol/L and 200 micromol/L as 2.38% and 1.92% for within-day CV, 3.7% and 2.4% for between-day CV respectively. Sulfosalicylic acid was used as internal standard. Linearity, between the concentrations of pseudouridine and the corresponding peak height or area ratios of pseudouridine and the internal standard, was demonstrated in the 6.25-200 micromol/L range (r>0.9990). The detection limit of concentration for pseudouridine was 4 micromol/L. This method, with simple sample preparation, good assay precision, lower cost and full-automation, is an effective means for the assessment of pseudouridine in clinical application.

Genomic analysis of single cells from human basal cell cancer using laser-assisted capture microscopy

In this study, we show that direct mutational analysis of genomic DNA can be performed on single somatic cells extracted from a frozen, immunohistochemically stained tissue section using laser-assisted capture microscopy. Eighty-nine single tumor cells were separately dissected from one case of human basal cell cancer (BCC) and p53 mutations were analyzed by direct semi-automated sequencing of PCR fragments. Amplification was obtained for at least one of the two analyzed exons from approximately 50% of the single tumor cells. Identical p53 mutations were found in widely spread areas of the tumor, suggesting a clonal proliferation originating from one cell. Interestingly, comparison between results of immunohistochemistry and genetic analysis of the single cells revealed the same p53 mutations irrespective of the p53 immunoreactivity. We propose that this approach has a great potential to allow investigation of genotypic differences in single cells and more specifically to resolve important and fundamental questions determining cancer heterogeneity.

Migration of medial smooth muscle cells to the intima after balloon injury

Migration to the intima and other responses of M-SMC in the rat carotid artery and abdominal aorta after balloon injury were investigated in vivo. Migration occurred intensively between the second and fifth days after injury. About 80% of the cells were in the G1 and S phases of the cell cycle. The majority of the migrating cells were therefore simultaneously proliferating. Positive values of 42.3%, 48.9%, 44.4%, and 32.8% of the migrating cells on the fifth day in the carotid artery for PDGF-B, elastase III B, MMP-I, and MMP-9, were observed, respectively. Many of the cells expressed messages of PDGF-A and elastases II and III B by in situ hybridization. Fine structures of the migrating cells were characterized as a synthetic phenotype of the smooth muscle cell with reduced attachment to their surrounding ECM. A biphasic proliferative response of the M-SMC appeared on the second and fifth days. Migration occurred correspondingly in the proliferative period. The populations of M-SMC positive in immunostainings for PDGFs, their receptors, elastase III B, and MMP-1 and MMP-9 also increased biphasically, around 12 h and five days after the injury. The results of these studies suggest that the migrating cells were proliferative and synthesizing PDGFs, elastases, and collagenases.

Effects of ethanol dependence on chronic spinal rats monitored by spontaneous hind leg movements

Physical dependence on ethanol was produced in rats whose spinal cords were transected at midthoracic level ("chronic spinal" rats) 2 months before chronic ethanol administration. Both intact and chronic spinal rats were treated with a light anesthetic dose of ethanol three times a day for 12 to 14 days and then abruptly withdrawn. All ethanol-treated animals exhibited severe withdrawal signs, including spontaneous withdrawal convulsions and death in over 60% of animals. In addition, ethanol-treated chronic spinal rats developed characteristic spontaneous hind leg movements (SLMs) during withdrawal. The time course, onset, peak and disappearance of these SLMs correlated well with other ethanol withdrawal signs. Cross dependence studies showed that ethanol, pentobarbital and barbital, diazepam and chlordiazepoxide, but not morphine, suppressed SLMs when drugs were administered at the peak intensity of SLM activities, while the intensity of behavioral withdrawal signs was also attenuated.

Isoniazid metabolism and binding by sensitive and resistant strains of Mycobacterium smegmatis

Suspensions of Mycobacterium smegmatis in buffer broke down isoniazid (INH) after a lag period and produced equivalent amounts of isonicotinic acid (INA). Smaller amounts of hydrazine were formed. If chloramphenicol (CAP) was added at the beginning of the incubation, INH did not disappear nor did INA or hydrazine appear. However, if CAP was added after INH had started to disappear, the fall in INH and the appearance of INA were the same as in the absence of CAP, and more hydrazine was formed. Sensitive and resistant cells caused similar reactions, except that the former produced somewhat more hydrazine. These results, and others with toluene-treated cells, suggest that INH is broken down by at least two induced enzymes, one of which splits INH to INA and hydrazine, and a second enzyme(s) which changes hydrazine to an unknown product. Lowering the incubation temperature slowed metabolic changes. Glycerol increased the rate of INH breakdown. Cyanide and azide inhibited breakdown. Azide had a much greater effect on INH-sensitive than on INH-resistant cells. Sensitive cells bound about twice as much radioactivity from 14C-labeled INH as resistant cells. Effects of temperature, metabolites, and inhibitors on binding were also studied. These experiments show that INH does not act as an inhibitor of protein synthesis or mRNA synthesis in sensitive cells and that resistant cells are permeable to INH, even though they bind less of the drug than sensitive cells.Isoniazid-sensitive and resistant strains were about equally susceptible to the growth-inhibitory action of hydrazine and hydroxylamine. Neither was inhibited by INA. During incubation of sensitive cells with INH in growth media very small amounts of hydrazine were formed, insufficient to inhibit growth. Resistant cells grew in the presence of INH without destroying significant amounts of it. Apparently INH itself, and not a metabolic product, is the inhibitory substance. Resistance does not depend on INH destruction.