WNT7A/β-catenin signaling induces FGF1 and influences sensitivity to niclosamide in ovarian cancer

We previously characterized the link between WNT7A and the progression of ovarian cancer. Other groups have identified FGF1 as a relevant risk factor in ovarian cancer. Here, we show a linkage between these two signaling pathways that may be exploited to improve treatment and prognosis of patients with ovarian cancer. High expression of WNT7A and FGF1 are correlated in ovarian carcinomas and poor overall patient survival. A chromatin immunoprecipitation assay demonstrated that WNT7A/β-catenin signaling directly regulates FGF1 expression via TCF binding elements in the FGF1-1C promoter locus. In vitro gene manipulation studies revealed that FGF1 is sufficient to drive the tumor promoting effects of WNT7A. In vivo xenograft studies confirmed that the stable overexpression of WNT7A or FGF1 induced a significant increase in tumor incidence, while FGF1 knockdown in WNT7A overexpressing cells caused a significant reduction in tumor size. Niclosamide most efficiently abrogated WNT7A/β-catenin signaling in our model, inhibited β-catenin transcriptional activity and cell viability, and increased cell death. Furthermore, niclosamide decreased cell migration following an increase in E-cadherin subsequent to decreased levels of SLUG. The effects of niclosamide on cell functions were more potent in WNT7A overexpressing cells. Oral niclosamide inhibited tumor growth and progression in an intraperitoneal xenograft mouse model representative of human ovarian cancer. Collectively, these results indicate that FGF1 is a direct downstream target of WNT7A/β-catenin signaling and this pathway has potential as a therapeutic target in ovarian cancer. Moreover, niclosamide is a promising inhibitor of this pathway and may have clinical relevance.

Single-arc volumetric-modulated arc therapy can provide dose distributions equivalent to fixed-beam intensity-modulated radiation therapy for prostatic irradiation with seminal vesicle and/or lymph node involvement

OBJECTIVES

Volumetric-modulated arc therapy (VMAT) is becoming an increasingly utilised modality for treating a variety of anatomical sites. However, the efficacy of single-arc VMAT to treat prostate cancer suspicious for extraprostatic extension was heretofore unknown. In this work, we report our institutional experience with single-arc VMAT and fixed-beam intensity-modulated radiation therapy (IMRT) for prostate cancer patients treated for seminal vesicle and/or lymph node involvement.

METHODS

Single-arc VMAT and 7- or 9-field IMRT treatment plans were compared for 10 prostate cancer patients treated for seminal vesicle involvement and/or lymph node involvement. All treatment plans were constructed using the Philips Pinnacle treatment planning system (v.9.0, Fitchburg, WI) and delivered on an Elekta Infinity radiotherapy accelerator (Crawley, UK). Resulting plans were compared using metrics that characterised dosimetry and delivery efficiency.

RESULTS

No statistically significant differences in target coverage, target homogeneity or normal tissue doses were noted between the plans (p>0.05). For prostate patients treated for seminal vesicle involvement, VMAT plans were delivered in 1.4±0.1 min (vs 9.5±2.4 min for fixed-beam IMRT) (p<0.01) and required approximately 20% fewer monitor units (p=0.01). For prostate patients treated for lymph node involvement, VMAT plans were delivered in 1.4±0.1 min (vs 11.7±1.3 min for fixed-beam IMRT) (p<0.01) and required approximately 45% fewer monitor units (p<0.01).

CONCLUSION

Single-arc VMAT plans were dosimetrically equivalent to fixed-beam IMRT plans with significantly improved delivery efficiency.

Role of cyclin inhibitor protein p21 in the inhibition of HCT116 human colon cancer cell proliferation by American ginseng (Panax quinquefolius) and its constituents

American ginseng and its ginsenoside constituents have been shown to exert anti-cancer effects although the mechanism of action remains unclear. The present study determined the effects of water-extracted ginseng (GE) or its ginsenoside (GF) and polysaccharide (PS) fractions on the proliferation of human colon cancer cells and examined the role of p21 in mediating these effects using wild-type and p21-/- HCT116 human colon carcinoma cells. Proliferation was inhibited by GE, GF, and PS in wild-type and p21-/- cells, and the p21-/- cells were more sensitive to these treatments. Wild type cells treated with GE were arrested in the G0/G1 phase of the cell cycle and the expression of p53 and p21 proteins was increased while phospho-MEK levels decreased. In contrast, cells deficient in p21 displayed reduced cell viability, elevated number of dead cells, and increased expression of Bax and cleaved caspase-3 proteins. Both polysaccharides and ginsenosides appear to be responsible for the anti-proliferative and proapoptotic effects of GE. This study suggests that p21 functions to arrest HCT116 wild-type cells treated with GE, while p21-deficient cells undergo cell death in a ginseng constituent-dependent manner.

Predictors of isotonic exercise in patients with heart failure

PURPOSE

Study aims were to determine the predictors of isotonic resistance exercise performance in patients with advanced heart failure and to compare the preexercise values of patients who experienced a negative physiologic response to resistance exercise with those who had minimal or no response.

METHODS

A correlational design was used. After pharmacologic left ventricular unloading therapy using a pulmonary artery catheter, 34 patients with advanced heart failure performed graduated isotonic weight-lifting exercises. Measurements were made of hemodynamics and rating of perceived exertion after each test.

RESULTS

The following variables, measured at baseline, were significantly correlated with the amount of weight patients were able to lift: rating of perceived exertion (RPE; r = -0.42, P = 0.014); diastolic blood pressure (DBP; r = 0.49, P = 0.03); systolic blood pressure (SBP; r = 0.40, P = 0.017); pulmonary capillary wedge pressure (PCWP; r = 0.39, P = 0.026); and right atrial pressure (RAP; r = 0.35, P = 0.041). Multiple regression analysis, using a stepwise procedure, showed that 47% of the variance in exercise performance was explained by DBP, RPE, and PCWP. There were no significant differences in baseline hemodynamics, ejection fraction, or age between the group of patients who had a negative hemodynamic response at peak exercise and the group of patients who had minimal or no response.

CONCLUSIONS

Resting PCWP, DBP, and RPE can provide important information to help clinicians predict isotonic resistance exercise performance in patients with advanced heart failure. However, those patients who have a negative response to this type of exercise cannot be distinguished at baseline by clinical characteristics or age.

Biochemical characterization of a cellular structure retaining vegetally localized RNAs in Xenopus late stage oocytes

Two pathways operate during Xenopus oogenesis to localize a small number of RNAs to the vegetal cortex. Correct localization of these RNAs is essential to normal development as the proteins they encode are involved in specifying cell type and in patterning the early embryo. Binding these RNAs to the vegetal cortex and thus preserving their localized condition is a critical step, although little is known about how this is achieved. In this study, we have used a biochemical approach to examine the anchoring step. Xlsirts, an abundant localized RNA (locRNA), was selectively enriched in a detergent-insoluble fraction (DIF) prepared from oocytes that had completed the RNA localization process. These putative RNA-anchoring complexes were analyzed by density gradient centrifugation and in RNA-protein binding assays. Cortical Xlsirts and other localized RNAs are specifically found in the heavy region of sucrose gradients and in the pellet, quite different from other cellular RNPs. Four proteins were identified by UV-crosslinking that bound the Xlsirts localization signal in the cortex, but not in the soluble fraction. These are likely members of the anchoring complex and appear to include vera, a characterized Vg1 RNA binding protein. Vera was found to co-sediment with other locRNAs found in the vegetal cortex, suggesting that it is a common component of locRNPs. Finally, we found that locRNPs extracted into the soluble fraction had the same buoyant density as typical ooplasmic RNPs. We propose that locRNAs are organized and anchored in the cortex as typical RNPs.

Germ plasm and molecular determinants of germ cell fate

One mechanism for the specification of cell types during embryonic development is the cytoplasmic localization of determinants in the egg into certain blastomeres. Primordial germ cell (PGC) development in many organisms is characterized by the inheritance of germ plasm, a cytologically distinct assembly of mitochondria and electron-dense germinal granules. This chapter reviews the structure of germ plasm and the experimental evidence for its importance in PGC specification in Caenorhabditis elegans, Drosophila, and Xenopus. It then compares and contrasts recent data on the identification of germ plasm components in these organisms. Many components are potentially RNA-binding proteins, implicating the regulation of RNA metabolism, transport, and translation as critical processes in PGC development. Germ plasm components also mediate transcriptional repression, regulate migration, and control mitotic divisions in PGCs. The chapter concludes with a discussion on the general roles of germ plasm components and how they might act to specify PGC fate.

The hemodynamic effects of isotonic exercise using hand-held weights in patients with heart failure

BACKGROUND

Controversy surrounds the use of resistance exercise in patients with heart failure because of concerns that increases in rate-pressure product and systemic vascular resistance might lead to increased afterload and decreased cardiac output.

METHODS

Following pharmacologic left ventricular unloading therapy using a pulmonary artery catheter, 34 patients with advanced heart failure performed isotonic weightlifting exercise at 50%, 65%, and 80% of the calculated one repetition maximum. Measurements were made of hemodynamics, ST segment, rate-pressure product, serum norepinephrine, rating of perceived exertion, and dysrhythmias following each exercise set.

RESULTS

Repeated analysis of variance showed significant increases in systolic blood pressure (p = 0.0005), diastolic blood pressure (p = 0.01), rate-pressure product (p = 0.005); serum norepinephrine (p = 0.004), and rating of perceived exertion (p = 0.0005). However, systemic vascular resistance and cardiac output did not change significantly (p>0.05). Pulmonary capillary wedge pressures, the incidence of dysrhythmias, and ST segments did not significantly differ from baseline. No patients experienced angina or dyspnea during the study.

CONCLUSIONS

Isotonic exercise using hand-held weights was well tolerated hemodynamically and clinically, and no patients experienced adverse outcomes during exercise.

DEADSouth is a germ plasm specific DEAD-box RNA helicase in Xenopus related to eIF4A

DEADSouth was selected in a screen for localized RNAs in Xenopus oocytes. In situ hybridization analysis shows that DEADSouth localizes to the vegetal cortex via the mitochondrial cloud early in oogenesis and segregates with germ plasm during early embryogenesis. These results lend further support for the general concept that the role of the early RNA localization pathway in Xenopus is to localize germ cell components (reviewed in King, M.L., Zhou, Y., Bubunenko, M. , 1999. BioEssays 21, 546-557). Further analysis shows that DEADSouth is a germline specific RNA, found exclusively within the germ plasm of oocytes and PGCs, as well as in male germ cells. Sequence comparisons with DEADSouth show it to be a member of a small sub-family of the DEAD-box RNA-dependent helicases related to eIF4A.

A critical role for Xdazl, a germ plasm-localized RNA, in the differentiation of primordial germ cells in Xenopus

Xdazl is an RNA component of Xenopus germ plasm and encodes an RNA-binding protein that can act as a functional homologue of Drosophila boule. boule is required for entry into meiotic cell division during fly spermatogenesis. Both Xdazl and boule are related to the human DAZ and DAZL, and murine Dazl genes, which are also involved in gamete differentiation. As suggested from its germ plasm localization, we show here that Xdazl is critically involved in PGC development in Xenopus. Xdazl protein is expressed in the cytoplasm, specifically in the germ plasm, from blastula to early tailbud stages. Specific depletion of maternal Xdazl RNA results in tadpoles lacking, or severely deficient in, primordial germ cells (PGCs). In the absence of Xdazl, PGCs do not successfully migrate from the ventral to the dorsal endoderm and do not reach the dorsal mesentery. Germ plasm aggregation and intracellular movements are normal indicating that the defect occurs after PGC formation. We propose that Xdazl is required for early PGC differentiation and is indirectly necessary for the migration of PGCs through the endoderm. As an RNA-binding protein, Xdazl may regulate translation or expression of factors that mediate migration of PGCs.

Effect of adhesive resin cement on design of partial veneer crowns

STATEMENT OF PROBLEM

Procedures involved in the tooth preparation, impression, and casting of partial veneer three-quarter crowns are considered to be complex.

PURPOSE

This study assessed whether a simplified partial veneer crown design, when cemented with a 4-META adhesive resin, had a comparable resistance to displacement forces compared with a conventionally prepared partial veneer crown cemented with a traditional luting agent.

MATERIAL AND METHODS

Conventional partial veneer crowns were prepared on 20 natural premolars, and 20 other premolars received modified partial veneer crown tooth preparations without proximal grooves. Artificial crowns were made for these teeth with Students alloy. Half the crowns in each of the 2 groups were luted with 4-META resin; the other half were luted with a zinc phosphate cement. Loads required to displace the partial veneer crowns were recorded after 24 hours and thermocycling, then the mode of separation was recorded for each crown. Average force required to displace partial veneer crowns for the 4 groups were subjected to 2-way analysis of variance and Scheffé test.

RESULTS

The 2 groups luted with 4-META resin and the group with proximal grooves luted with zinc phosphate were not significantly different. However, they were all greater than the group without proximal grooves luted with zinc phosphate cement.

CONCLUSION

Forces required to displace partial veneer crowns prepared in a traditional manner and those teeth prepared without proximal grooves were similar if the artificial crowns were luted with adhesive resin cement.

Polarizing genetic information in the egg: RNA localization in the frog oocyte

RNA localization is a powerful strategy used by cells to localize proteins to subcellular domains and to control protein synthesis regionally. In germ cells, RNA targeting has profound implications for development, setting up polarities in genetic information that drive cell fate during embryogenesis. The frog oocyte offers a useful system for studying the mechanism of RNA localization. Here, we discuss critically the process of RNA localization during frog oogenesis. Three major pathways have been identified that are temporally and spatially separated in oogenesis. Each pathway uses a different mechanism to effect RNA localization. In some cases, localization elements within the 3' untranslated region have been identified and have provided unique insights into the localization process. This important field is still in its infancy, however, and much remains to be learned.

Xcat2 RNA is a translationally sequestered germ plasm component in Xenopus

In Xenopus, the inheritance of germ plasm by a small subset of blastomeres during early development is thought to direct these cells into the germ cell lineage. We show that Xcat2 RNA, related to Drosophila nanos, is a germ plasm component that is translationally repressed during oogenesis. Xcat2 protein was not detected in oocytes at times prior to, or after its RNA was localized in germ plasm, suggesting Xcat2 RNA is functionally sequestered soon after transcription. Indeed, Xcat2 RNA is found in a dense non-polysomal compartment in oocytes. Repression of translation was not relieved by substituting the Xcat2 3'UTR with that of beta-globin. Immunodetection of Xcat2 protein during blastula and gastrula stages coincides with the time of symmetric segregation of the germ plasm and a net increase in the number of primordial germ cells. Xcat2 is capable of binding RNA in vitro and we propose that it may function to translationally regulate other RNAs specific to primordial germ cells.

The role of maternal VegT in establishing the primary germ layers in Xenopus embryos

VegT is a T-box transcription factor whose mRNA is synthesized during oogenesis and localized in the vegetal hemisphere of the egg and early embryo. We show that maternally expressed VegT controls the pattern of primary germ layer specification in Xenopus embryos. Reduction of the maternal store completely alters the fates of different regions of the blastula so that animal cell fate is changed from epidermis and nervous system to epidermis only, equatorial cell fate is changed from mesoderm to ectoderm, and vegetal cell fate is changed from endoderm to mesoderm and ectoderm. Vegetal cells lose their capacity both to form endoderm and to release mesoderm-inducing signals. These results show that a single maternally expressed gene controls the patterning of the Xenopus blastula.

A Xenopus DAZ-like gene encodes an RNA component of germ plasm and is a functional homologue of Drosophila boule

We have identified a localized RNA component of Xenopus germ plasm. This RNA, Xdazl (Xenopus DAZ-like), encodes a protein homologous to human DAZ (Deleted in Azoospermia), vertebrate DAZL and Drosophila Boule proteins. Human males deficient in DAZ have few or no sperm and boule mutant flies exhibit complete azoospermia and male sterility. Xdazl RNA was detected in the mitochondrial cloud and vegetal cortex of oocytes. In early embryos, the RNA was localized exclusively in the germ plasm. Consistent with other organisms, Xdazl RNA was also expressed in the spermatogonia and spermatocytes of frog testis. Proteins in the DAZ-family contain a conserved RNP domain implying an RNA-binding function. We have shown that Xdazl can function in vitro as an RNA-binding protein. To determine if the function of Xdazl in spermatogenesis was conserved, we introduced the Xdazl cDNA into boule flies. This resulted in rescue of the boule meiotic entry phenotype, including formation of spindles, phosphorylation of histone H3 and completion of meiotic cell division. Overall, these results suggest that Xdazl may be important for primordial germ cell specification in the early embryo and may play a role analogous to Boule in promoting meiotic cell division.

Heart-rate variability in chronic traumatic brain injury

Heart-rate variability (HRV), a measure of fluctuation around the mean heart rate, reflects the sympathetic and parasympathetic balance of the autonomic nervous system, and is an excellent technique to study cardiovascular tone in patients with neurological injuries. The purpose of this study was to determine whether abnormal HRV is present in patients with traumatic brain injury (TBI) during the post-acute recovery phase. Using a prospective, case/control design, we performed 24-h ambulatory ECG monitoring in seven TBI patients and in seven controls (C). There was a significant difference in root mean squared successive difference of RR intervals (C 40.4 +/- 10.3, TBI 23.3 +/- 16.5, p = 0.04) between TBI and C. Four patients with TBI (compared to one control) had abnormal standard deviation of the RR interval. When these four patients were compared to their matched controls, significant differences were found in frequency domain measure (In total power: TBI 4.4 +/- 0.9 ms2, C 7.1 +/- 1.4 ms2, In low frequency: TBI 3.3 +/- 1.1 ms2, C 6.4 +/- 1.4 ms2; In high frequency TBI 2.0 +/- 1.0 ms2, C 4.8 +/- 1.3 ms2, all p < 0.05). Thus, abnormalities in both time and frequency domains of HRV are present in TBI during the post-acute recovery phase.

Cloning and expression of a Xenopus laevis oocyte lectin and characterization of its mRNA levels during early development

cDNA clones encoding a soluble, calcium-dependent, melibiose-binding lectin from Xenopus laevis oocytes have been isolated, characterized, and expressed in bacteria. This lectin has been shown by others to be localized in oocyte cortical granules where it ultimately is released and participates in the formation of the fertilization envelope. A lectin with similar specificity has been purified by others from blastula and immunolocalized to specific locations in developing embryos, which suggests it may also function after fertilization in regulating cell adhesion and migration. We have used melibiose affinity chromatography to isolate the oocyte lectin (monomer molecular masses of about 45 and 43 kDa) and shown that after exhaustive treatment with N-glycanase, only one major protein band at 35 kDa was observed, suggesting that a single polypeptide with variable N-linked glycosylation is expressed in the oocyte. After obtaining internal peptide sequences, a PCR-based cloning approach allowed the isolation of full length cDNAs from an ovary lambda gt11 library encoding a protein of 313 amino acids with three potential N-linked oligosaccharide sites. Although this lectin, termed XL35, requires calcium ions for oligosaccharide binding, its sequence does not contain the sequence motif defined for "C-type" lectins. A 6-Histagged from of the lectin was expressed in E. coli and purified on a Ni(2+)-NTA column from bacterial extracts. The recombinant lectin was active using an agglutination assay, and this activity was inhibitable by EDTA and melibiose, properties exhibited by the native lectin. Southern blot analysis revealed a single hybridizing band, arguing against the existence of a multigene family. Northern blot analysis demonstrated that the lectin mRNA is expressed in oocytes and remains at relatively high levels through late gastrulae, continuing until tadpole stages. The persistence of the lectin mRNA, coupled with results from earlier studies, strongly suggests that XL35 is zygotically expressed and functions during morphogenesis.

Xenopus VegT RNA is localized to the vegetal cortex during oogenesis and encodes a novel T-box transcription factor involved in mesodermal patterning

An RNA localized to the vegetal cortex of Xenopus oocytes encodes a novel T-box protein (VegT) capable of inducing either dorsal or posterior ventral mesoderm at different times in development. VegT is a nuclear protein and its C-terminal domain can activate transcription in a yeast reporter assay, observations consistent with VegT functioning as a transcription factor. Zygotic expression is dynamic along the dorsoventral axis, with transcripts first expressed in the dorsal marginal zone. By the end of gastrulation, VegT is expressed exclusively in posterior ventral and lateral mesoderm and is excluded from the notochord. Later expression is confined to a subset of Rohon-Beard cells, a type of primary sensory neuron. In animal cap assays, VegT is capable of converting prospective ectoderm into ventral lateral mesoderm. Such ectopic expression of VegT induces its own expression as well as that of Xwnt-8 in caps, suggesting that a Wnt pathway may be involved. Mis-expression of VegT in dorsal animal blastomeres fated to contribute to brain suppresses head formation. Our results suggest that VegT is a localized transcription factor, which operates sequentially in several developmental pathways during embryogenesis, including dorsoventral and posterior patterning of mesoderm.

RNA transport to the vegetal cortex of Xenopus oocytes

Xcat-2 RNA, a component of the germ plasm in Xenopus, localizes with the mitochondrial cloud material to the vegetal cortex in stage II oocytes. Vg1 RNA also localizes to the vegetal cortex, but later in stage III/IV oocytes, using a microtubule dependent pathway. To further analyze the mechanisms involved in RNA transport, in situ hybridization and autoradiography were used to follow the localization of endogenous Vg1 and injected Xcat-2 transcripts in stage IV oocytes. We show that Xcat-2 is competent to localize to the vegetal cortex quite independently of the mitochondrial cloud. Xcat-2 RNA appears to use the late Vg1 localization pathway, as depolymerization of microtubules by cold or nocodazole treatment prevented translocation of Xcat-2 transcripts, but did not result in the disruption of Xcat-2 anchored in the cortex. Furthermore, RNA transport was shown to be stage dependent for both Vg1 and Xcat-2 RNAs, as they did not localize in fully grown stage VI oocytes after injection. RNA sequences both required and sufficient to direct Xcat-2 to the vegetal cortex were mapped to a sequence of 150 nt immediately adjacent to the open reading frame and additional sequences at the end of the 3' untranslated region. Mapping was accomplished by injecting deletion mutant transcripts into stage IV oocytes and monitoring localization by RNase protection and autoradiography. All mutants competent for translocation were also capable of cortical anchoring, suggesting that the same signal is used for both steps. We speculate that two separate RNA pathways evolved during the course of Xenopus oogenesis. One pathway, specialized for the transport of germ plasm by way of the mitochondrial cloud, occurs early to ensure the segregation of the germ cell lineage. The other, late, pathway may serve as the more general transport system for localizing RNAs involved in somatic cell differentiation.

Localization of Xcat-2 RNA, a putative germ plasm component, to the mitochondrial cloud in Xenopus stage I oocytes

The mitochondrial cloud is a unique cell structure found in stage I Xenopus oocytes that plays a role in mitochondriogenesis and in the distribution of germ plasm to the vegetal pole. Xcat-2 RNA specifically localizes to the mitochondrial cloud and moves with it to the vegetal subcortex in stage II oocytes. Later, in the 4-cell embryo, it is found in a pattern identical to the germ plasm. Following microinjection into stage I oocytes, synthetic Xcat-2 RNAs localize to the mitochondrial cloud within 22 hours. Transcripts are stable over this time period with very little evidence of degradation. The Xcat-2 3′untranslated region was found to be both required and sufficient for mitochondrial cloud localization. Further deletion analysis narrowed this localization signal to a 250 nucleotide region at the proximal end of the 3′untranslated region. This region is different from, but overlaps with, a domain previously shown to be sufficient to direct Xcat-2 to the vegetal cortex in stage IV oocytes. Examination of early stage I oocytes reveals a time when Xcat-2 is uniformly distributed, arguing against vectorial nuclear export into the mitochondrial cloud. Analysis of localization at different time points does not suggest active transport to the mitochondrial cloud. We postulate that localization occurs by selective entrapment of Xcat-2 within the cloud by localized binding sites.

A Fluted Point from the Uptar Site, Northeastern Siberia

Lanceolate bifacial points, including one fluted specimen, have been collected from beneath an early Holocene tephra at the Uptar site, northeastern Siberia. Thus, the technology associated with the well-known Paleoindian tradition was not confined to the Americas. The Uptar collection does not compare readily with other Beringian complexes and demonstrates that there is greater diversity in the archaeological record of northeastern Siberia than traditional colonization models imply.

Isolation and characterization of xnov, a Xenopus laevis ortholog of the chicken nov gene

We have isolated an ortholog (xnov) of the chicken nov gene (for nephroblastoma overexpressed; encoding a putative avian proto-oncogene) from Xenopus laevis (Xl) by screening an Xl ovary cDNA library and genomic library using the entire coding region of human CTGF (encoding connective tissue growth factor) as a probe and by 5'RACE (rapid amplification of cDNA ends). xnov has the same genomic organization as chicken nov, mouse fisp12 and cyr61, but has a unique promoter sequence. The Xl open reading frame (ORF) encodes a 343-amino-acid (aa) polypeptide of 37.9 kDa. Xnov shows 62.9, 60.5, 52.2, 52.1, 47.6 and 45.8% identity with the chicken Nov, human NovH, human CTGF, mouse Fisp12, chicken Cef10 and mouse Cyr61 proteins, respectively. Xnov contains four aa domains which characterize the CTGF family. RT-PCR (reverse transcription-polymerase chain reaction) analysis shows that the xnov mRNA is very low in abundance and appears to be present throughout early Xl development. Our results also indicate that xnov and nov are not orthologs of human CTGF.

Celahinine A, a new sesquiterpene pyridine alkaloid from Celastrus hindsii

A new sesquiterpene pyridine alkaloid, celahinine A [1], and the related known polyester celahin A, as well as the known cytotoxic sesquiterpene pyridine alkaloid emarginatine A [2], were isolated from Celastrus hindsii. The structure of 1 was determined by 2D nmr techniques and was also confirmed by spectral comparison with the related 2.

Effect of a tracheostomy speaking valve on secretions, arterial oxygenation, and olfaction: a quantitative evaluation

Tracheostomy speaking valves consist of a one-way valve that closes upon exhalation, causing a redirection of exhaled gas into the upper airway, thus allowing for the primary benefit of speech. The present study was undertaken to test various hypotheses concerning the secondary benefits of speaking valves. We hypothesized that use of a speaking valve will result in a decrease in accumulated secretions, an increase in arterial oxygenation and an improvement in olfactory function. A total of 8 tracheotomized patients met the following inclusion criteria: age > 18; ability to tolerate wearing a speaking valve for at least 3 hours; no unstable medical conditions; no use of thrombolytic agents. While using the speaking valve patients accumulated fewer secretions (74.3 +/- 63.6 vs. 122.8 +/- 44.6 ml/day, p = 0.004, n = 7) and had improved olfactory function (accuracy = 28.4 +/- 5.2 vs 8.1 +/- 2.9%, p = 0.02; and percent correct = 64.2 +/- 2.6 vs 50.0 +/- 3.9%, p = 0.03, n = 6) than when off the speaking valve. No significant differences were found in 24-hour arterial oxygen saturation (pulse oximetry and ABG analysis respectively, n = 7), arterial PO2, pH, PCO2, HCO3, or 24-hour heart rate (n = 7). Thus, the present study found a significant decrease in secretions and improvements in olfaction when tracheotomized patients wore a speaking valve, but no difference in arterial oxygenation.

Adjuvant radiation therapy for rectal carcinoma: predictors of outcome

PURPOSE

To review predictors of outcome, including sequencing of modalities and pretreatment findings for adjuvantly treated rectal cancer.

METHODS AND MATERIALS

From 1975 through 1990, 307 patients with adenocarcinoma of the rectum underwent adjuvant radiation therapy. In 251 cases the radiation therapy was administered preoperatively, either 40-50 Gy (median dose 45 Gy) followed in 6-7 weeks by surgery (210 cases), or 20 Gy in five fractions immediately prior to surgery (41 cases). In 56 cases, patients were referred postoperatively for radiation (median dose 50 Gy). Adjuvant chemotherapy was never given concurrently with the preoperative radiation (RT), although 43 of the cases (including 14 of the preoperative RT cases) received postoperative chemotherapy.

RESULTS

Multivariate analysis (Cox model) indicated that significant predictors of better overall freedom from disease were preoperative rather than postoperative RT (p < 0.001), low surgical stage (p < 0.0001), specialist surgeon (p = 0.007), low or moderate histologic grade (p = 0.026), and proximal lesion (p = 0.033). The significant predictors for better local control included use of preoperative RT (p < 0.001), low or moderate grade (p = 0.001), and low surgical stage (p = 0.015). The 5-year local control and freedom from disease for the preoperative RT patients were 90% +/- 2% and 73% +/- 3%, respectively. The selected cases that received the short course of 20 Gy preoperatively did well. Although 24 out of 41 patients proved to have Astler Coller B2 or C disease, local control at last follow-up was 39 out of 41 (95%). A second multivariate analysis of pretreatment factors was performed on the preoperative RT cases. The significant factors for both local control and overall freedom from disease were noncircumferential vs. circumferential tumor, proximal vs. distal lesion, and background of the surgeon. Additional negative factors on univariate analysis (although not achieving independent significance on multivariate analysis) included the finding of near-obstructing lesions and elevated carcinoembryonic antigen (CEA). Grade > or = 3 sequelae occurred in 8% of cases (including 3% bowel obstruction). The only significant factor for complications was background of the surgeon (4% for colorectal specialists vs. 12% for nonspecialists, p = 0.015).

CONCLUSIONS

Significant factors for better tumor control included preoperative as opposed to postoperative RT and the experience of the surgeon. In selected cases, excellent results can be obtained with a short course of preoperative radiation. Concurrent chemotherapy need not be given routinely with preoperative radiation. Subgroups of preoperative RT cases at risk for distant metastases (who might benefit from postoperative chemotherapy), and at high risk for local failure (for whom concurrent preoperative chemotherapy and radiation might be considered), are identified.

Application of physiotherapy outcome measures to the managed care model

Managed Care (MC) is a multidisciplinary model for health care delivery that organizes and sequences the caregiving process. Its objectives include: 1) to reduce length of stay and resource consumption, and 2) to measure, maintain or improve patient outcomes related to care received. Our tertiary care facility is the first Canadian hospital to implement MC. Patient care is directed through the use of a Care Map. Each map is specific to a pathological state and its treatment, i.e. Total Knee Replacement (TKR), and consists of a Patient Problem List, with related patient-centred outcomes, and a Critical Path. The Critical Path outlines the temporal sequence of the provision of care. Most key events on a Care Map are determined anecdotally. The purpose of this project was to collect outcome information in patients assigned to the Total Knee Replacement Care Map in an attempt to validate the existing Care Map or make recommendations for revisions. Inter-rater and intra-rater reliability of knee range of motion-was calculated using the Intra Class Correlation Coefficient (ICC). ICC values ranged from .64-.97. Seventeen patients were assessed. All patients were measured on Day 6 and 8 of the Care Map. This process has resulted in validation of certain range estimates and recommendations for revision of others.

Patterns of localization and cytoskeletal association of two vegetally localized RNAs, Vg1 and Xcat-2

In Xenopus, localization of a rare class of mRNAs during oogenesis is believed to initiate pattern formation in the early embryo. We have determined the pattern of RNA localization for one of these RNAs, Xcat-2, which encodes a putative RNA-binding protein related to Drosophila nanos (Mosquera, L., Forristall, C., Zhou, Y. and King, M. L. (1993) Development 117, 377–386). Xcat-2 is exclusively localized to the mitochondrial cloud in stage I oocytes, moves with this body into the vegetal cortex during stage II and, later, partitions into islands consistent with it being a component of the germ plasm. As previously shown, Vg1 is not localized to the vegetal cortex until stage IV and distributes to all vegetal blastomeres during development. We found a direct correlation between the localized condition of these RNAs and their recovery in a detergent-insoluble fraction. We present evidence suggesting that differential RNA binding to a cytoskeletal component(s) in the vegetal cortex determines the pattern of inheritance for that RNA in the embryo.

A double-blind randomized controlled trial of colchicine in patients with hepatitis B virus-related postnecrotic cirrhosis

The preliminary results of a prospective double-blind controlled trial of colchicine in 100 patients with hepatitis B virus-related cirrhosis are reported. The patients, 94 males and 6 females, aged 32-80, were assigned to receive either 1 mg of colchicine or an identical placebo orally on a daily basis. The duration of the follow up ranged from 15 to 51 months (median 26 months). Seventy percent had histological proof of cirrhosis. On entry, 80 patients were in Child-Pugh class A, 19 were in class B, and one was in class C. Compared to the placebo group, there was no improvement in the colchicine group after a 24-month follow up in any of the biochemistry data, for example, serum albumin, alkaline phosphatase, alanine and aspartate aminotransferase, bilirubin, and prothrombin time. The difference in the cumulative survival rates at 51 months did not reach statistical significance (p = 0.8) in either group. There was no histological improvement in 30 patients who were willing to undergo repeated liver biopsies. No trend toward improvement of the hepatic pressure gradient was observed in these patients. The serum levels of aminopropeptide of type III procollagen increased significantly in patients in both groups after 24 months of therapy (1.07 +/- 0.06 vs. 1.36 +/- 0.06 U/ml in the colchicine group, 0.93 +/- 0.09 vs. 1.25 +/- 0.07 U/ml in the placebo group; p < 0.05). In addition, neither the clinical deterioration of cirrhosis nor death was prevented in patients receiving colchicine therapy. This report indicates that colchicine has no effect in the treatment of HBV-related postnecrotic cirrhosis.

Exertional hypotension in spinal cord injury

STUDY OBJECTIVE

To assess blood pressure (BP) response to continuous maximal arm ergometry in patients with spinal cord injury (SCI).

DESIGN

Cross-sectional analysis of data collected for a prospective study of functional electrical stimulation in patients with SCI.

SETTING

Short-term rehabilitation hospital.

PARTICIPANTS

Twenty individuals with SCI; 4 cervical (C6 to C8), 10 high thoracic (T1 to T6), and 6 low thoracic (T7 to T12).

MEASUREMENTS AND RESULTS

Each subject performed continuous maximal arm ergometry with expired gas analysis. Blood pressure was measured using a technician-assisted protocol. The BP at maximal exercise was compared with the highest submaximal BP reached during the test (delta BP = final BP minus highest submaximal BP). All 20 subjects had a negative delta BP (mean +/- SD; -22.8 +/- 12.1 mm Hg) for mean BP and 19 of 20 had a negative delta BP (-25.8 +/- 14.4 mm Hg) for systolic BP. The delta BP was not significantly related to maximum exercise parameters, resting BP, or level of lesion. Four able-bodied subjects and six wheelchair-bound individuals without SCI showed no exertional hypotension. Repeated testing on the four able-bodied subjects showed excellent reproducibility for mean BP (coefficient of variation [CV] = 3.6 percent; r = 0.98; p < 0.01) and systolic BP (CV = 2.2 percent; r = 0.99; p < 0.01) using this protocol.

CONCLUSIONS

These data describe, for the first time to our knowledge, that exertional hypotension is present in all individuals with SCI during continuous arm ergometry. Further studies are needed to clarify the mechanisms responsible for this phenomenon and to evaluate the long-term consequences for individuals with SCI.

Two new macrolide sesquiterpene pyridine alkaloids from Maytenus emarginata: emarginatine G and the cytotoxic emarginatine F

Two new macrolide sesquiterpene pyridine alkaloids, emarginatine F [1] and emarginatine G [2], were isolated from Maytenus emarginata. The structural determinations of 1 and 2 by 2D nmr techniques and spectral comparison with a related compound, emarginatine A [3], are discussed. Biological evaluation showed that emarginatine F [1] demonstrated strong cytotoxicity against human epidermoid carcinoma of the nasopharynx (KB), ileocecal adenocarcinoma (HCT-8), melanoma (RPMI-7951) and medulloblastoma (TE-671) tumor cells, and against murine leukemia (P-388).

Isolated vegetal cortex from Xenopus oocytes selectively retains localized mRNAs

The process of converting an egg to a multicellular organism often begins with a polarization of information within the oocyte. The cytoskeleton plays an important role in maintaining such asymmetries. Here we describe the isolation and characterization of cortices, rich in cytoskeletal elements, from the animal and vegetal poles of stage VI Xenopus oocytes. Ultrastructural and immunocytochemical analyses revealed that the 10-microns-thick isolates included a cytokeratin network, mitochondria, and other elements, found in the oocyte cortex. Furthermore, three vegetally localized mRNAs, Vg1, Xcat-2, and Xcat-3, were all found to be specifically retained within the isolated vegetal cortices, in sharp contrast to histone RNA. Our findings support the view that the vegetal cortex represents a unique cytoskeletal domain in which a rare class of maternal mRNAs becomes localized.

A mRNA localized to the vegetal cortex of Xenopus oocytes encodes a protein with a nanos-like zinc finger domain

mRNAs concentrated in specific regions of the oocyte have been found to encode determinants that specify cell fate. We show that an intermediate filament fraction isolated from Xenopus stage VI oocytes specifically contains, in addition to Vg1 RNA, a new localized mRNA, Xcat-2. Like Vg1, Xcat-2 is found in the vegetal cortical region, is inherited by the vegetal blasomeres during development, and is degraded very early in development. Sequence analysis suggests that Xcat-2 encodes a protein that belongs to the CCHC RNA-binding family of zinc finger proteins. Interestingly, the closest known relative to Xcat-2 in this family is nanos, an RNA localized to the posterior pole of the Drosophila oocyte whose protein product suppresses the translation of the transcription factor hunchback. The localized and maternally restricted expression of Xcat-2 RNA suggests a role for its protein in setting up regional differences in gene expression that occur early in development.

Exertional hypotension in thoracic spinal cord injury: case report

Exertional hypotension is well described in quadraplegics, but there are few descriptions of this hemodynamic response in paraplegics or of treatment modalities to correct this condition. We describe a patient with a complete T3-4 spinal cord lesion who repeatedly demonstrated symptomatic hypotension with wheelchair sports and arm ergometry. We used gas exchange analysis and exercise echocardiography to delineate the mechanism for hypotension. These results enabled us to develop a simple treatment plan consisting of abdominal binding and elastic stockings to avoid recurrent symptoms.

Potential liability in utilization review: the risk grows

The use of cost containment measures in utilization review is a continuing topic of concern to physicians and payors. Focusing on a recent California case that dealt with this issue, this article discusses the potential liability of physicians and payors when such measures are used.

Determination of fenoverine, a modulator of smooth muscle motility, in capsules and in human plasma: application to dosage form stability and a pilot study in humans

Fenoverine is a novel, potent, musculotropic, spasmolytic agent that affects primarily the gastrointestinal tract, bile duct, and female genital organs. A simple, specific, and accurate HPLC method was developed for the determination of fenoverine in capsules and plasma. This method has been successfully applied to stability studies of fenoverine capsules and to a pilot study in a normal, healthy volunteer following oral administration of fenoverine. For the determination of fenoverine in capsules, a Nucleosil 5-micron CN column, with acetonitrile:0.1 M ammonium acetate (60:40) as mobile phase and detection at 254 nm, was employed. The mean correlation coefficient of the calibration curve (n = 6) for the assay was 0.9999 over a concentration range of 24.6 to 147.6 micrograms/mL of fenoverine standard solutions. Fenoverine did not decompose significantly at 4, 45, 55, and 65 degrees C for 3 months. The mean correlation coefficients of within-day and between-day calibration curves were 0.9995 and 0.9999, respectively, over a range of 10 to 1000 ng/mL of fenoverine in plasma. The limit of detection was 10 ng in plasma.

Developmental expression of regionally specific cell surface antigens in the Xenopus gastrula

Molecular markers for specific cell lineages would be useful in studies of cellular differentiation. To isolate such markers monoclonal antibodies (MoABs) were raised against plasma membranes isolated from gastrulating Xenopus embryos. Those antibodies that recognized subsets of cells within the embryo were selected by indirect immunofluorescence. The analysis of eight such MoAbs is presented. Western blot analysis showed that all but one MoAb recognized a complex pattern of glycoconjugates associated with glycoproteins. All the antigens recognized by the MoAbs were maternal in origin and displayed similar spatial patterns of pregastrular expression. This pattern of immunoreactivity at the apical surface was inherited passively during cleavage by the resulting superficial blastomeres suggesting that ectodermal specific markers of maternal origin are pre-localized to the cortical ooplasm in mature oocytes. We suggest that these maternal components may be specific glycosyl transferases. Three different patterns of expression were observed during gastrulation as exemplified by MoAbs 1F10C1, 3A4D1, and 6F10B6. MoAb 6F10B6 was specific for both neural and non-neural epithelium. MoAb 3A4D1 was specific for non-neural epidermis. MoAb 1F10C1 appeared to recognize a protein epitope on an extracellular component expressed by the superficial and involuting epithelial cells. The pattern of expression for the 1F10C1 antigen suggests that it may play a role in facilitating the movement of the involuting cells during gastrulation.

The developmental expression of the heat-shock response in Xenopus laevis

We have investigated the Xenopus heat-shock response of somatic cells, oocytes and embryos. Xenopus defolliculated oocytes displayed a highly variable response to heat shock depending on the culture medium. Intact follicles, however, respond to heat stress by synthesizing an invariant pattern of hsps. Although a subset of the hsp70/68 complex is expressed constitutively in the absence of heat shock in oocytes and embryos (hsc70), actual induction of hsps in response to stress does not occur until the blastula stage when transcription of the zygotic genome is first activated. By gastrulation, the hsps of somatic cells, including members of the hsp30/26 complex, were expressed coordinately in response to heat shock. We further show that Xenopus hsps have different solubilities perhaps reflecting their different subcellular locations. The 26,000–30,000 Mr complex (hsp30/26) was present almost exclusively in a detergent-insoluble fraction, as was 25–50% of the hsp70/68 complex and greater than 50% of hsp56, suggesting that these hsps may be associated with the cytoskeleton during a heat shock. In contrast, the other Xenopus hsps (hsp86, hsp75 and hsp61) were totally solubilized in a low-salt buffer.

Localized maternal mRNA related to transforming growth factor beta mRNA is concentrated in a cytokeratin-enriched fraction from Xenopus oocytes

The localized maternal RNA Vg1 resides in the cortical region of the vegetal pole of fully grown Xenopus oocytes and is inherited by only a subset of blastomeres in the early embryo [Weeks, D. L. & Melton, D. A. (1987) Cell 51, 861-867]. Because RNA-cytoskeletal interactions may play a role in RNA localization, we have examined the association of Vg1 RNA with components of the oocyte's cytoskeleton. Gel and immunoblot analysis of a detergent-insoluble fraction revealed a greatly simplified protein pattern composed largely of cytokeratins and vimentin. In sharp contrast to the nonlocalized histone H3 mRNA, Vg1 RNA was concentrated some 35- to 50-fold in this insoluble fraction. Extractions at higher salt concentrations yielded preparations further enriched in cytokeratins and in the Vg1 RNA. Upon ovulation, VG1 RNA is released into the soluble fraction. This change in Vg1 RNA distribution coincides with the observed breakdown of cortical cytokeratin filaments [Klymkowsky, M. W., Maynell, L. A. & Polson, A. G. (1987) Development 100, 543-557] and the loss of Vg1 RNA from the cortical region. Our findings are consistent with the hypothesis that RNA-cytoskeletal interactions are involved in the localization and segregation of information during development.

Expression and segregation of nucleoplasmin during development in Xenopus

The spatial segregation of informational molecules in the unfertilized egg and embryo has been hypothesized to be a necessary phenomenon for the normal progression of development leading to the determination of cellular phenotypes. This study describes the selection of a monoclonal antibody (Mab: 2G6) that identifies an antigen (Ag: 2G6) which is localized in the germinal vesicle of oocytes and has a discrete pattern of inheritance during embryogenesis. The antigen displayed biochemical and physical characteristics very similar to nucleoplasmin, which is the histone-binding and nucleosome-assembly protein previously described. Immunoblot analysis with purified oocyte nucleoplasmin confirmed this relationship. Indirect immunofluorescence was used to study the temporal expression and spatial distribution of nucleoplasmin. From early cleavage stages through gastrulation, it is preferentially localized in nuclei of blastomeres at the animal pole. By tadpole stages, it was detected only in nuclei of postmitotic cells of the central nervous system and in nuclei of striated muscle. It was not detected in adult tissues. Western blot analysis during embryogenesis revealed at least five immunologically related polypeptides that displayed distinct patterns of expression during development. The different species observed most likely represent different levels of phosphorylation of nucleoplasmin. The more acidic forms, known to be more active in nucleosome assembly, were present during cleavage stages. Analysis of labelled oocyte proteins by two-dimensional immunoblots and autoradiography revealed that synthesis of nucleoplasmin was first detected in stage-2 oocytes, reached 60% maximum levels at stage 3, peaked at stage 4 and was undetectable in stage-6 oocytes. The amount of nucleoplasmin message present does not follow a similar pattern during oogenesis. These results suggest that the message undergoes pronounced changes in translational efficiency during oogenesis. A comparative immunoblot analysis using proteins from a variety of adult tissues revealed that, whereas the polyclonal antisera against amphibian vitellogenic oocyte nucleoplasmin recognized several different, tissue-specific polypeptides, two different monoclonal antibodies (Mab: b7-1D1, Mab: 2G6) failed to recognize any of the adult tissues tested. We conclude that nucleoplasmin is a family of closely related proteins with distinct embryonic and adult members.