Prediction of key milk biomarkers in dairy cows through milk mid-infrared spectra and international collaborations

At the individual cow level, suboptimum fertility, mastitis, negative energy balance, and ketosis are major issues in dairy farming. These problems are widespread on dairy farms and have an important economic impact. The objectives of this study were (1) to assess the potential of milk mid-infrared (MIR) spectra to predict key biomarkers of energy deficit (citrate, isocitrate, glucose-6 phosphate [glucose-6P], free glucose), ketosis (β-hydroxybutyrate [BHB] and acetone), mastitis (N-acetyl-β-d-glucosaminidase activity [NAGase] and lactate dehydrogenase), and fertility (progesterone); (2) to test alternative methodologies to partial least squares (PLS) regression to better account for the specific asymmetric distribution of the biomarkers; and (3) to create robust models by merging large datasets from 5 international or national projects. Benefiting from this international collaboration, the dataset comprised a total of 9,143 milk samples from 3,758 cows located in 589 herds across 10 countries and represented 7 breeds. The samples were analyzed by reference chemistry for biomarker contents, whereas the MIR analyses were performed on 30 instruments from different models and brands, with spectra harmonized into a common format. Four quantitative methodologies were evaluated to address the strongly skewed distribution of some biomarkers. Partial least squares regression was used as the reference basis, and compared with a random modification of distribution associated with PLS (random-downsampling-PLS), an optimized modification of distribution associated with PLS (KennardStone-downsampling-PLS), and support vector machine (SVM). When the ability of MIR to predict biomarkers was too low for quantification, different qualitative methodologies were tested to discriminate low versus high values of biomarkers. For each biomarker, 20% of the herds were randomly removed within all countries to be used as the validation dataset. The remaining 80% of herds were used as the calibration dataset. In calibration, the 3 alternative methodologies outperform the PLS performances for the majority of biomarkers. However, in the external herd validation, PLS provided the best results for isocitrate, glucose-6P, free glucose, and lactate dehydrogenase (coefficient of determination in external herd validation [R2v] = 0.48, 0.58, 0.28, and 0.24, respectively). For other molecules, PLS-random-downsampling and PLS-KennardStone-downsampling outperformed PLS in the majority of cases, but the best results were provided by SVM for citrate, BHB, acetone, NAGase, and progesterone (R2v = 0.94, 0.58, 0.76, 0.68, and 0.15, respectively). Hence, PLS and SVM based on the entire dataset provided the best results for normal and skewed distributions, respectively. Complementary to the quantitative methods, the qualitative discriminant models enabled the discrimination of high and low values for BHB, acetone, and NAGase with a global accuracy around 90%, and glucose-6P with an accuracy of 83%. In conclusion, MIR spectra of milk can enable quantitative screening of citrate as a biomarker of energy deficit and discrimination of low and high values of BHB, acetone, and NAGase, as biomarkers of ketosis and mastitis. Finally, progesterone could not be predicted with sufficient accuracy from milk MIR spectra to be further considered. Consequently, MIR spectrometry can bring valuable information regarding the occurrence of energy deficit, ketosis, and mastitis in dairy cows, which in turn have major influences on their fertility and survival.

Recurrence of Breast Cancer After Primary Treatment: A Matched Comparison Study of Disease-Free Survival in Women Who Do and Do Not Receive Adjunctive Naturopathic Oncology Care

Purpose:

To compare disease free survival experienced by women who received usual oncologic care compared to a cohort of women who received naturopathic oncology care in addition to usual care.

Methods:

Women with breast cancer who received naturopathic oncology (NO) care in Western Washington State (WA) (N = 176) were recruited to a prospective study of clinical health-related quality of life outcomes and then matched to women who received usual care (UC) only (N = 334).

Results:

Among 510 women with breast cancer stages 1 to 3, a total of 50 women (10%) experienced a disease-free survival (DFS) ending event within the observation period; 23 (6.8% of those in the UC cohort, and 27 (15.3% of those in the NO cohort (P < .05). Although, women in the 2 cohorts received similar surgical, chemotherapy, and radiation treatment, women with breast cancer who received naturopathic oncology adjunctive care were less likely to use anti-estrogen therapy, and experienced poorer DFS (logrank test, P < .05). However, differences in DFS could not be shown to be due to cohort differences in anti-estrogen therapy, baseline HRQOL, or naturopathic oncology therapies prescribed. The stage 3 women in the naturopathic oncology group had more advanced disease at diagnosis. They were more likely to have 5 or more metastatic lymph nodes at baseline (18.5%) compared to their usual care matched control group (13%). Women in the naturopathic oncology group also had higher grade tumors at diagnosis.

Conclusions:

Results show that recurrence of breast cancer was associated with more advanced malignant lymph node involvement; and that naturopathic oncology services provided in 2009-2015 did not improve disease-free survival in these high-risk breast cancer patients.

An Intervention to Improve Medication Adherence in People With Heart Disease (Text4HeartII): Randomized Controlled Trial

Background

Mobile health technologies have the potential to improve the reach and delivery of interventions for promoting long-term secondary prevention of coronary heart disease.

Objective

This study aims to determine the effectiveness of an SMS text messaging intervention (Text4HeartII) for improving adherence to medication and lifestyle changes over and above usual care in people with coronary heart disease at 24 and 52 weeks.

Methods

A two-arm, parallel, randomized controlled trial was conducted in New Zealand. Participants with a recent acute coronary syndrome were randomized to receive usual cardiac services alone (control, n=153) or a 24-week SMS text message program for supporting self-management plus usual cardiac services (n=153). The primary outcome was adherence to medication at 24 weeks, defined as a medication possession ratio of 80% or more for aspirin, statin, and antihypertensive therapy. Secondary outcomes included medication possession ratio at 52 weeks, self-reported medication adherence, adherence to healthy lifestyle behaviors, and health-related quality of life at 24 and 52 weeks.

Results

Participants were predominantly male (113/306, 80.3%) and European New Zealanders (210/306, 68.6%), with a mean age of 61 years (SD 11 years). Groups were comparable at baseline. National hospitalization and pharmacy dispensing records were available for all participants; 92% (282/306, 92.1%) of participants completed a 24-week questionnaire and 95.1% (291/306) of participants completed a 52-week questionnaire. Adherence with 3 medication classes were lower in the intervention group than in the control group (87/153, 56.8% vs 105/153, 68.6%, odds ratio 0.60, 95% CI 0.38-0.96; P=.03) and 52 weeks (104/153, 67.9% vs 83/153, 54.2%; odds ratio 0.56, 95% CI 0.35-0.89; P=.01). Self-reported medication adherence scores showed the same trend at 52 weeks (mean difference 0.3; 95% CI 0.01-0.59; P=.04). Moreover, self-reported adherence to health-related behaviors was similar between groups.

Conclusions

Text4HeartII did not improve dispensed medication or adherence to a favorable lifestyle over and above usual care. This finding contrasts with previous studies and highlights that the benefits of text interventions may depend on the context in which they are used.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12616000422426; http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=370398.

International Registered Report Identifier (IRRID)

RR2-10.1186/s13063-018-2468-z

The human hematopoietic stem cell compartment is heterogeneous for CXCR4 expression

The chemokine stromal derived factor-1alpha (SDF-1alpha) has been implicated recently in the chemotaxis of primitive human hematopoietic cells, suggesting that pluripotent human stem cells express the SDF-1alpha receptor, CXCR4. By using flow cytometry and confocal microscopy, we have identified and isolated primitive subsets of human CXCR4(+) and CXCR4(-) cells. Distinctions in the progenitor content and response to SDF-1alpha in vitro indicate that CXCR4(+) and CXCR4(-) cells represent discrete populations of primitive blood cells. The i.v. transplantation of these subfractions into immune-deficient mice established that both possess comparable engraftment capacity in vivo. Human myeloid, lymphoid, and primitive CD34(+) CXCR4(+) cells were present in chimeric animals transplanted with either subset, indicating that CXCR4(+) and CXCR4(-) stem cells have equivalent proliferative and differentiative abilities. Our study indicates that the human stem cell compartment is heterogeneous for CXCR4 expression, suggesting that the relationship between CXCR4 expression and stem cell repopulating function is not obligatory.

Pattern formation: a new twist to BMP signalling

Dorsal-ventral patterning in Xenopus and Drosophila embryos involves BMP family signalling molecules. Twisted Gastrulation has now been added to the list of proteins that regulate the activity of these molecules, providing new insights into how BMPs are made available to their signalling receptors.

A BMP pathway regulates cell fate allocation along the sea urchin animal-vegetal embryonic axis

To examine whether a BMP signaling pathway functions in specification of cell fates in sea urchin embryos, we have cloned sea urchin BMP2/4, analyzed its expression in time and space in developing embryos and assayed the developmental consequences of changing its concentration through mRNA injection experiments. These studies show that BMP4 mRNAs accumulate transiently during blastula stages, beginning around the 200-cell stage, 14 hours postfertilization. Soon after the hatching blastula stage, BMP2/4 transcripts can be detected in presumptive ectoderm, where they are enriched on the oral side. Injection of BMP2/4 mRNA at the one-cell stage causes a dose-dependent suppression of commitment of cells to vegetal fates and ectoderm differentiates almost exclusively as a squamous epithelial tissue. In contrast, NOGGIN, an antagonist of BMP2/4, enhances differentiation of endoderm, a vegetal tissue, and promotes differentiation of cells characteristic of the ciliated band, which contains neurogenic ectoderm. These findings support a model in which the balance of BMP2/4 signals produced by animal cell progeny and opposing vegetalizing signals sent during cleavage stages regulate the position of the ectoderm/ endoderm boundary. In addition, BMP2/4 levels influence the decision within ectoderm between epidermal and nonepidermal differentiation.

Cloning and expression of the Wnt antagonists Sfrp-2 and Frzb during chick development

The Wnt genes are known to play fundamental roles during patterning and development of a number of embryonic structures. Receptors for Wnts are members of the Frizzled family of proteins containing a cysteine-rich domain (CRD) that binds the Wnt protein. Recently several secreted frizzled-related proteins (Sfrps) that also contain a CRD have been identified and some of these can both bind and antagonise Wnt proteins. In this paper we report the expression patterns of the chick homologues of Frzb, a known Wnt antagonist, and Sfrp-2. Both genes are expressed in areas where Wnts are known to play a role in development, including the neural tube, myotome, cartilage, and sites of epithelial-mesenchymal interactions. Initially, Sfrp-2 and Frzb are expressed in overlapping areas in the neural plate and neural tube, whereas later, they have distinct patterns. In particular Sfrp-2 is associated with myogenesis while Frzb is associated with chondrogenesis, suggesting that they play different roles during development. Finally, we have used the early Xenopus embryo as an in vivo assay to show that Sfrp-2, like Frzb, is a Wnt antagonist. These results suggest that Sfrp-2 and Frzb may function in the developing embryo by modulating Wnt signalling.

Vertebrate development: Multiple phases to endoderm formation

Recent results support a two-step model for endoderm formation in amphibian embryos, in which endoderm is initially specified by localised maternal factors, including the transcription factor VegT, but is then maintained by extracellular signalling molecules of the transforming growth factor-beta family.

BMP signalling in early Xenopus development

Bone morphogenetic proteins (BMPs) are typically members of the transforming growth factor beta (TGF-beta) family with diverse roles in embryonic development. At least five genes with homology to BMPs are expressed during Xenopus development, along with their receptors and intracellular signalling pathways. The evidence suggests that BMPs have roles to play in both mesoderm induction and dorsoventral patterning. Studies in Xenopus have also identified a number of inhibitory binding proteins for the classical BMPs, encoded by genes such as chordin and noggin. These proteins appear to be responsible for establishing a morphogen gradient of BMP4 activity, which specifies different dorsoventral fates in early gastrulae. An emerging theme is that inhibition of BMP signalling is an important mechanism regulating cell fate decisions in early development.

Bone morphogenetic protein 1 regulates dorsal-ventral patterning in early Xenopus embryos by degrading chordin, a BMP4 antagonist

Bone morphogenetic protein 1 (BMP1) is a metalloprotease that ventralises dorsal mesoderm when overexpressed in early Xenopus embryos. Here we show that Xenopus BMP1 blocks the dorsalising activity of chordin, but not noggin or DeltaxBMPR, when coexpressed in the ventral marginal zone and degrades chordin protein in vitro. We also show that a dominant-negative mutation for XBMP1 (dnBMP1) dorsalises ventral mesoderm in vivo, and blocks degradation of chordin by both XBMP1 and Xolloid, a closely related Xenopus metalloprotease, in vitro. dnBMP1 does not dorsalise ventral mesoderm in UV-irradiated embryos, demonstrating that this activity is dependent upon a functional organiser--the natural source of chordin in Xenopus gastrulae. Our results suggest that XBMP1 may regulate the availability of chordin during vertebrate embryogenesis.

Human growth differentiation factor 9 (GDF-9) and its novel homolog GDF-9B are expressed in oocytes during early folliculogenesis

Growth differentiation factor 9 (GDF-9) is a transforming growth factor-beta family member that is required for normal folliculogenesis in female mice, but its role as a regulator of human fertility is still unclear. We determined here by in situ hybridization and immunohistochemical analyses the localization of the GDF-9 messenger ribonucleic acid (mRNA) and protein during human folliculogenesis. The GDF-9 transcripts were not detected in primordial follicles, but they are abundantly expressed in primary follicles in frozen sections of ovarian cortical tissue material obtained at laparoscopic surgery. We raised antipeptide antibodies against GDF-9 and showed by immunohistochemical studies on paraffin sections of whole human ovaries that the GDF-9 protein is most abundantly expressed in primary follicles. We recently demonstrated that a novel GDF-9-related factor, GDF-9B, is coexpressed with GDF-9 during murine folliculogenesis. We now isolated human GDF-9B complementary DNA and genomic clones and report the unusually restricted expression pattern of human GDF-9B. The human GDF-9B transcript can be detected only in the gonads by RT-PCR analysis, and in situ hybridization studies indicate that it is not expressed in small primary follicles but, rather, in the oocytes of late primary follicles. Functional studies using the Xenopus laeuis embryo model indicate that unlike the transforming growth factor-beta family members activin and bone morphogenetic protein-4, neither GDF-9 nor GDF-9B affects mesoderm induction, suggesting that they may use signaling pathways distinct from those well defined for activin and bone morphogenetic protein-4. We conclude that 1) both GDF-9 mRNA and protein are abundantly expressed in oocytes of primary follicles in human ovary, suggesting that the GDF-9 transcript is translated at this early stage of folliculogenesis; 2) human GDF-9B is specifically expressed in gonads at low levels; and 3) the expression of GDF-9 mRNA begins slightly earlier than that of GDF-9B in the human oocytes during follicular development. Our results are consistent with the suggestion that GDF-9 and GDF-9B may regulate human folliculogenesis in a manner specific to the ovary.

A gradient of BMP activity specifies dorsal-ventral fates in early Xenopus embryos

BMP-4 is an extracellular signalling molecule belonging to the TGF-beta superfamily that plays a central role in dorsoventral patterning in vertebrate gastrulae. We review the evidence indicating that BMP-4 acts as a morphogen, specifying dorsoventral positional values in a concentration-dependent manner. An activity gradient of BMP-4 is established not by simple diffusion from a localised source, but by diffusion of inhibitory binding proteins that act on a uniform level of BMP-4 protein. These in turn are regulated by the activity of tolloid-related metalloproteases, such as Xenopus xolloid and zebrafish tolloid.

Regulation of BMP signaling by the BMP1/TLD-related metalloprotease, SpAN

We have used the Xenopus embryo as a test system for analyzing the activity of SpAN, a sea urchin metalloprotease in the astacin family containing BMP1 and tolloid. Embryos expressing SpAN initiated gastrulation on a time scale indistinguishable from controls, but invagination of the vegetal pole was subsequently delayed by several hours. At tailbud stages the most severely affected embryos were completely ventralized, lacking all dorsal structures. Molecular analysis of injected embryos, using probes for both dorsal (xgsc and xnot) and ventral (xhox3 and xwnt8) mesoderm, indicates that SpAN ventralizes dorsal mesoderm during gastrula stages. These results mirror those previously obtained with BMP4, suggesting that SpAN may enhance the activity of this ventralizing factor. Consistent with this suggestion, we have shown that SpAN blocks the dorsalizing activity of noggin and chordin, two inhibitory binding proteins for BMP4, but not that of a dominant-negative receptor for BMP4. In contrast, a dominant-negative SpAN, in which the metalloprotease domain has been deleted, dorsalizes ventral mesoderm, a phenotype that can be rescued by coexpressing either SpAN or XBMP1. This suggests that SpAN is mimicking a Xenopus metalloprotease responsible for regulating the activity of Xenopus BMPs during gastrulation. Moreover, our results raise the possibility that SpAN may function to facilitate BMP signaling in early sea urchin embryos.

BMP1-related metalloproteinases promote the development of ventral mesoderm in early Xenopus embryos

Bone morphogenetic protein 1 (BMP1) is a metalloproteinase closely related to Drosophila Tolloid (Tld). Tld regulates dorsoventral patterning in early Drosophila embryos by enhancing the activity of Dpp, a member of the TGF-beta family most closely related to BMP2 and BMP4. In Xenopus BMP4 appears to play an essential role in dorsoventral patterning, promoting the development of ventral fates during gastrula stages. To determine if BMP1 has a role in regulating the activity of BMP4, we have isolated cDNAs for Xenopus BMP1 and a novel closely related gene that we have called xolloid (xld). Whereas xbmp1 is uniformly expressed at all stages tested, the initial uniform expression of xld becomes localized to two posterior ectodermal patches flanking the neural plate and later to the inner ectoderm of the developing tailbud. xld is also expressed in dorsal regions of the brain during tailbud stages and is especially abundant in the ventricular layer of the dorsal hindbrain caudal to the otic vesicle. Overexpression of either gene inhibits the development of dorsoanterior structures in whole embryos and ventralizes activin-induced dorsal mesoderm in animal caps. Since ventralization of activin-induced animal caps can be blocked by coinjecting a dominant-inhibitory receptor for BMP2 and BMP4, we suggest a role for BMP1 and Xld in regulating the ventralizing activity of these molecules.

Development: morphogen gradients and mesodermal patterning

Activin has long-range effects in Xenopus development, inducing the mesodermally expressed brachyury gene up to 10 cell diameters from a localised source. Recent experiments show that activin diffuses through tissues to establish a morphogen gradient, and that the long-range effects are a direct result of activin signalling.

Cleavage of Chordin by Xolloid metalloprotease suggests a role for proteolytic processing in the regulation of Spemann organizer activity

The Xolloid secreted metalloprotease, a tolloid-related protein, was found to cleave Chordin and Chordin/BMP-4 complexes at two specific sites in biochemical experiments Xolloid mRNA blocks secondary axes caused by chordin, but not by noggin, follistatin, or dominant-negative BMP receptor, mRNA injection. Xolloid-treated Chordin protein was unable to antagonize BMP activity. Furthermore, Xolloid digestion released biologically active BMPs from Chordin/BMP inactive complexes. Injection of dominant-negative Xolloid mRNA indicated that the in vivo function of Xolloid is to limit the extent of Spemann's organizer field. We propose that Xolloid regulates organizer function by a novel proteolytic mechanism involving a double inhibition pathway required to pattern the dorsoventral axis: [formula in text].

Early expression of a novel nucleotide receptor in the neural plate of Xenopus embryos

Extracellular ATP functions as a neurotransmitter and neuromodulator in the adult nervous system, and a signaling molecule in non-neural tissue, acting either via ligand-gated ion channels (P2X) or G-protein-coupled receptors (P2Y). ATP can cause an increase in intracellular Ca2+ (Ca2+i) in embryonic cells and so regulate cell proliferation, migration, and differentiation. We have isolated a Xenopus cDNA encoding a novel P2Y receptor, XlP2Y, which is expressed abundantly in developing embryos. Recombinant XlP2Y responds equally to all five naturally occurring nucleoside triphosphates (ATP, UTP, CTP, GTP, and ITP), which elicit a biphasic Ca2+-dependent Cl- current (ICl,Ca) where the second phase persists for up to 60 min. XlP2Y also causes a continuous release of Ca2+i and a low level persistent activation of ICl,Ca in Xenopus oocytes through the spontaneous efflux of ATP. mRNAs for XlP2Y are expressed transiently in the neural plate and tailbud during Xenopus development, coincident with neurogenesis. This restricted pattern of expression and novel pharmacological features confer unique properties to XlP2Y, which may play a key role in the early development of neural tissue.

Stroke caregivers: do they feel prepared?

A pilot study was administered to determine if stroke caregivers felt they were adequately educated, trained, and prepared to care for their stroke survivor upon discharge. The convenience sample consisted of 26 stroke caregivers from four Indiana facilities with established therapy/rehabilitation units and two Indiana stroke clubs. Subjects were divided into groups according to the amount of time after discharge in the caregiver role (1-3 days, 10-14 days, greater than 3 months). Survey results were obtained by phone interviews and by self-administration. Compilation of data occurred over 5 months, and interpretation involved visual inspection and frequency distributions. Overall preparedness for the newer caregivers was a 4 (prepared); whereas, the more experienced caregivers' average score was a 3 (somewhat prepared). This study can help rehabilitation staff in their efforts to prepare caregivers for assisting stroke survivors at home.

Minimally invasive cardiac surgery for removal of the greater saphenous vein

OBJECTIVE

To determine if saphenous vein required for coronary bypass could be quickly, easily and safely removed with a minimally invasive technique.

DESIGN

A consecutive series.

SETTING

A university centre.

MATERIAL AND METHODS

In cadavers, a standard mediastinoscope was used to remove segments of the greater saphenous vein. Thigh segments, superior leg segments and ankle segments were removed. Fifteen minutes were allowed for removal of a segment.

RESULTS

Segments of vein 15 to 17 cm long could be removed. One segment could not be removed within 15 minutes. Thigh segments were easy to remove, calf segments were the most difficult. There were no avulsed side branches. All incisions were less than 5 cm long.

CONCLUSIONS

Saphenous vein can be harvested quickly and safely by a minimally invasive method. Lower extremity complications may be reduced and long-term patency improved with this in-situ technique of vein removal.

Bone morphogenetic protein-4 (BMP-4) acts during gastrula stages to cause ventralization of Xenopus embryos

Injection of RNA encoding BMP-4 into the early Xenopus embryo suppresses formation of dorsal and anterior cell types. To understand this phenomenon, it is necessary to know the stage at which BMP-4 acts. In this paper, we present three lines of evidence showing that BMP-4 misexpression has no effect on the initial steps of mesoderm induction, either dorsal or ventral, but instead causes ventralization during gastrulation. Firstly, activation of organizer-specific genes such as goosecoid, Xnot, pintallavis and noggin occurs normally in embryos injected with BMP-4 RNA, but transcript levels are then rapidly down-regulated as gastrulation proceeds. Similarly, BMP-4 does not affect the initial activation of goosecoid by activin in animal caps, but expression then declines precipitously. Secondly, embryos made ventral by injection with BMP-4 RNA cannot be rescued by grafts of Spemann's organizer at gastrula stages. Such embryos therefore differ from those made ventral by UV-irradiation, where the defect occurs early and rescue can be effected by the organizer. Finally, the dorsalizing effects of the organizer, and of the candidate dorsalizing signal noggin, both of which exert their effects during gastrulation, can be counteracted by BMP-4. Together, these experiments demonstrate that BMP-4 can act during gastrulation both to promote ventral mesoderm differentiation and to attenuate dorsalizing signals derived from the organizer.

Postinfarction ventricular septal rupture: repair by endocardial patch with infarct exclusion

A novel operative technique for postinfarction ventricular septal defect has been used in 44 consecutive patients. The operation consists of excluding rather than excising the infarcted septum and ventricular walls. This is accomplished by performance of a left ventriculotomy through the infarcted muscle and securing a glutaraldehyde-fixed bovine pericardium patch to the endocardium of the left ventricle all around the infarcted myocardium. The ventriculotomy is simply closed over the pericardial patch. There were 21 men and 23 women whose mean age was 69 +/- 7 years. Twenty-nine patients were in cardiogenic shock at the time of operation. All patients had Doppler echocardiography and coronary angiography before operation. All but two patients were operated on during the acute phase of the myocardial infarction. There were six operative deaths. Postoperative complications included renal failure in 10 patients and respiratory failure in 18. Severe right ventricular dysfunction was the only independent predictor of operative mortality. Patients have been followed up for a mean of 40 +/- 34 months. There have been six late deaths and three of these were because of cardiac problems. The actuarial survival at 6 years was 66% +/- 7%. Only one patient had a small residual ventricular septal defect. Late postoperative assessment of ventricular function by echocardiography revealed that most patients had normal or mild impairment of right ventricular function and mild or moderate impairment of left ventricular function. Repair of acute postinfarction ventricular septal defect by endocardial patch with infarct exclusion of the left ventricule probably avoids additional damage to the right ventricle, remodels the acutely infarcted left ventricle, and enhances survival.

Effects of truncated activin and FGF receptors and of follistatin on the inducing activities of BVg1 and activin: does activin play a role in mesoderm induction?

Activin and Vg1, two members of the TGF-beta family, are believed to play roles in mesoderm induction and axis formation in the amphibian embryo. Both molecules are provided maternally, either as protein (activin) or as RNA and protein (Vg1), and experiments with a truncated form of a type IIB activin receptor have led to the conclusion that activin is required for induction of mesoderm in vivo. In this paper we first show that truncated versions of two different Xenopus activin receptors also have severe effects on the activity of the mature region of Vg1, suggesting that such receptors may block the function of several members of the TGF-beta family. We go on to demonstrate that follistatin, a secreted protein which binds activin and blocks its activity, does not interfere with Vg1 signalling. Furthermore, overexpression of follistatin mRNA in Xenopus embryos does not perturb mesoderm formation. Taken together, our data show that the effects of truncated activin receptors on Xenopus development can be explained by the inhibition of Vg1 activity, while the lack of effect of follistatin argues against a function for activin in mesoderm induction.

Secretion and mesoderm-inducing activity of the TGF-beta-related domain of Xenopus Vg1

Vg1 is a maternal mRNA localized to the vegetal hemisphere of Xenopus embryos during blastula stages, a region responsible for the induction of mesoderm in the adjacent marginal zone. Its homology to the transforming growth factor-beta family, which includes several proteins with mesoderm-inducing activity, suggests a role for Vg1 as an endogenous mesoderm-inducing factor. However, expression of Vg1 protein in the animal hemisphere, following injection of synthetic mRNA, has no effect on development, and isolated animal caps are not mesodermalized. It is shown that Vg1 protein fails to form dimers and is not processed to release the putative bioactive domain. Furthermore it is shown that the N-terminal signal peptide of Vg1 is not cleaved following translocation into the ER, which may explain the failure of this protein to dimerize. To explore the role of Vg1 in amphibian development, a fusion protein has been made of the preproregion of Xenopus bone morphogenetic protein-4 and the putative bioactive C-terminal domain of Vg1. This fusion protein forms dimers and the C-terminal domain of Vg1 is secreted. Injection of this construct into Xenopus embryos induces the formation of a second dorsal axis and isolated animal caps are mesodermalized. The results are consistent with a role for Vg1 in mesoderm induction during Xenopus development.

Bone morphogenetic protein 4: a ventralizing factor in early Xenopus development

The mesoderm of amphibian embryos such as Xenopus laevis arises through an inductive interaction in which cells of the vegetal hemisphere of the embryo act on overlying equatorial and animal pole cells. Three classes of 'mesoderm-inducing factor' (MIF) that might be responsible for this interaction in vivo have been discovered. These are members of the transforming growth factor type beta (TGF-beta), fibroblast growth factor (FGF) and Wnt families. Among the most potent MIFs are the activins, members of the TGF-beta family, but RNA for activin A and B is not detectable in the Xenopus embryo until neurula and late blastula stages, respectively, and this is probably too late for the molecules to act as natural inducers. In this paper, we use the polymerase chain reaction to clone additional members of the TGF-beta family that might possess mesoderm-inducing activity. We show that transcripts encoding Xenopus bone morphogenetic protein 4 (XBMP-4) are detectable in the unfertilized egg, and that injection of XBMP-4 RNA into the animal hemisphere of Xenopus eggs causes animal caps isolated from the resulting blastulae to express mesoderm-specific markers. Surprisingly, however, XBMP-4 preferentially induces ventral mesoderm, whereas the closely related activin induces axial tissues. Furthermore, the action of XBMP-4 is 'dominant' over that of activin. In this respect, XBMP-4 differs from basic FGF, another ventral inducer, where simultaneous treatment with FGF and activin results in activin-like responses. The dominance of XBMP-4 over activin may account for the ability of injected XBMP-4 RNA to 'ventralize' whole Xenopus embryos. It is interesting, however, that blastopore formation in such embryos can occur perfectly normally. This contrasts with embryos ventralized by UV-irradiation and suggests that XBMP-4-induced ventralization occurs after the onset of gastrulation.

Secretory and inductive properties of Drosophila wingless protein in Xenopus oocytes and embryos

Like its vertebrate homologues, Xenopus wnt-8 and murine wnt-1, we find that Drosophila wingless (wg) protein causes axis duplication when overexpressed in embryos of Xenopus laevis after mRNA injection. In many cases, the secondary axes contain eyes and cement glands, which reflect the induction of the most dorsoanterior mesodermal type, prechordal mesoderm. We show that the extent of axis duplication is dependent on the embryonic site of expression, with ventral expression leading to a more posterior point of axis bifurcation. The observed duplications are due to de novo generation of new axes as shown by rescue of UV-irradiated embryos. The true dorsal mesoderm-inducing properties of wg protein are indicated by its ability to generate extensive duplications after mRNA injection into D-tier cells of 32-cell embryos. As revealed by lineage mapping, the majority of these D cell progeny populate the endoderm; injections into animal blastomeres at this stage are far less effective in inducing secondary axes. However, when expressed in isolated animal cap explants, wg protein induces only ventral mesoderm, unless basic fibroblast growth factor is added, whereupon induction of muscle and occasionally notochord is seen. We conclude that in intact embryos, wg acts in concert with other factors to cause axis duplication. Immunolocalisation studies in embryos indicate that wg protein remains localised to the blastomeres synthesizing it and has a patchy, often perinuclear distribution within these cells, although some gets to the surface. In oocytes, the pool of wg protein is entirely intracellular and relatively unstable. When the polyanion suramin is added, most of the intracellular material is recovered in the external medium.

Developmental expression of the protein product of Vg1, a localized maternal mRNA in the frog Xenopus laevis

Vg1 is a maternal mRNA localized in the vegetal cortex of Xenopus laevis oocytes, that encodes a protein homologous to the mammalian growth factor TGF-beta. Using a polyclonal antibody to a T7-Vg1 fusion protein, we have identified the native protein. We find that a single protein of Mr 40 kd is immunoprecipitated following in vitro translation of oocyte poly(A)+ RNA, whilst two proteins of Mr 45 and 43.5 kd are immunoprecipitated from oocyte and embryo extracts. Synthesis of at least the 40 kd, in vitro, and 45 kd, in vivo, proteins is specifically inhibited following treatment of the respective systems with antisense Vg1 (but not histone H4) oligodeoxynucleotides. Tunicamycin treatment reveals the in vivo proteins to be glycosylated versions of a 40 kd protein, modified by the addition of either two or three N-linked oligosaccharide side chains. Both proteins are sensitive to digestion by the enzyme endoglycosidase-H, and are segregated within a membrane fraction from which they can be released by high pH treatment. Their synthesis is first detectable in stage IV oocytes and continues throughout early embryogenesis until the late gastrula. During embryogenesis the relative proportions of the two proteins change, the 45 kd protein being predominant in early embryogenesis and the 43.5 kd protein in late embryogenesis. Synthesis only occurs in the vegetal hemisphere at all stages; however, in the large oocyte diffusion of both proteins into the animal hemisphere occurs.

Antisense oligodeoxyribonucleotide-directed cleavage of maternal mRNA in Xenopus oocytes and embryos

We have investigated the effect of specific antisense oligodeoxynucleotides (oligos) on endogenous histone H4 mRNA in Xenopus oocytes, eggs and embryos. In unfertilised eggs and non-matured oocytes, one 20-mer oligo (H4-1) mediated the RNAse H-like cleavage of up to 95% of H4 mRNA (which included polysomal mRNA), and cleavage was still obtained when the size of the oligo was reduced to a 10-mer; no cleavage was observed with 6- and 8-mers. The residual uncleaved mRNA appeared to be completely inaccessible to H4-1 since a second injection caused no further cleavage. A second 20-mer (H4-2) directed against a different region of H4 mRNA was much less effective (less than 5% cleavage). In fertilised embryos, injections of H4-1 and an oligo directed against the localised Vg1 mRNA caused less cleavage than in oocytes and also showed signs of inducing localised, non-specific mRNA cleavage. However we have been able to prepare fertilised embryos devoid of Vg1 mRNA by maturing and fertilising oligo-injected oocytes in vitro.

Side effects after diagnostic lumbar puncture and lumbar iohexol myelography

A prospective, controlled study was performed to compare side effect incidences after lumbar iohexol myelography (n = 97) and diagnostic lumbar puncture (n = 85). No significant side effect incidence differences (iohexol vs. controls) were found regarding number of patients with any side effect (63 vs. 73%), headache (44 vs. 54%), nausea, dizziness, visual, auditory, or psychic symptoms. Early-onset headache occurred significantly more often in the iohexol group (17 vs 5%), while postural headache occurred most frequently after lumbar puncture (25 vs. 41%). These results suggest that apart from the slight early-onset headache, most side effects after lumbar iohexol myelography are related to the puncture per se, not to the contrast agent.

Regional specification within the mesoderm of early embryos of Xenopus laevis

We have further analysed the roles of mesoderm induction and dorsalization in the formation of a regionally specified mesoderm in early embryos of Xenopus laevis. First, we have examined the regional specificity of mesoderm induction by isolating single blastomeres from the vegetalmost tier of the 32-cell embryo and combining each with a lineage-labelled (FDA) animal blastomere tier. Whereas dorsovegetal (D1) blastomeres induce 'dorsal-type' mesoderm (notochord and muscle), laterovegetal and ventrovegetal blastomeres (D2-4) induce either 'intermediate-type' (muscle, mesothelium, mesenchyme and blood) or 'ventral-type' (mesothelium, mesenchyme and blood) mesoderm. No significant difference in inductive specificity between blastomeres D2, 3 and 4 could be detected. We also show that laterovegetal and ventrovegetal blastomeres from early cleavage stages can have a dorsal inductive potency partially activated by operative procedures, resulting in the induction of intermediate-type mesoderm. Second, we have determined the state of specification of ventral blastomeres by isolating and culturing them in vitro between the 4-cell stage and the early gastrula stage. The majority of isolates from the ventral half of the embryo gave extreme ventral types of differentiation at all stages tested. Although a minority of cases formed intermediate-type and dorsal-type mesoderms we believe these to result from either errors in our assessment of the prospective DV axis or from an enhancement, provoked by microsurgery, of some dorsal inductive specificity. The results of induction and isolation experiments suggest that only two states of specification exist in the mesoderm of the pregastrula embryo, a dorsal type and a ventral type. Finally we have made a comprehensive series of combinations between different regions of the marginal zone using FDA to distinguish the components. We show that, in combination with dorsal-type mesoderm, ventral-type mesoderm becomes dorsalized to the level of intermediate-type mesoderm. Dorsal-type mesoderm is not ventralized in these combinations. Dorsalizing activity is confined to a restricted sector of the dorsal marginal zone, it is wider than the prospective notochord and seems to be graded from a high point at the dorsal midline. The results of these experiments strengthen the case for the three-signal model proposed previously, i.e. dorsal and ventral mesoderm inductions followed by dorsalization, as the simplest explanation capable of accounting for regional specification within the mesoderm of early Xenopus embryos.

Fate map for the 32-cell stage of Xenopus laevis

A complete fate map has been produced for the 32-cell stage of Xenopus laevis. Embryos with a regular cleavage pattern were selected and individual blastomeres were injected with the lineage label fluorescein-dextran-amine (FDA). The spatial location of the clones was deduced from three-dimensional (3D) reconstructions of later stages and the volume of each tissue colonized by labelled cells in each tissue was measured. The results from 107 cases were pooled to give a fate map which shows the fate of each blastomere in terms of tissue types, the composition of each tissue by blastomere, the location of each prospective region on the embryo and the fate of each blastomere in terms of spatial localization. Morphogenetic movements up to stage 10 (early gastrula) were assessed by carrying out a number of orthotopic grafts at blastula and gastrula stages using donor embryos uniformly labelled with FDA. Although there is a regular topographic projection from the 32-cell stage this varies a little between individuals because of variability of positions of cleavage planes and because of short-range cell mixing during gastrulation. The cell mixing means that the topographic projection fails for anteroposterior segments of the dorsal axial structures and it is not possible to include short segments of notochord or neural tube or individual somites on the pregastrulation fate map.

Chemical meningitis in metrizamide myelography. A report of seven cases

Seven patients with acute chemical meningitis after metrizamide myelography are described. Five of the cases occurred within a time span of two months. Clinical and cerebrospinal fluid findings in the acute stage of the illness were similar to findings in acute bacterial meningitis. Possible causes of this complication are discussed.

Computed tomography in early stages of testicular carcinoma. Size of normal retroperitoneal lymph nodes and lymph nodes in patients with metastases in stage II A. A SWENOTECA study: Swedish-Norwegian Testicular Cancer Project

From the SWENOTECA Project, the CT findings in 156 patients treated by bilateral retroperitoneal lymphadenectomy were reviewed. Of these, 112 were in stage I (no metastases) and 44 in stage II A (metastases in normal-sized lymph nodes and in nodes with a maximum diameter in the transverse plane of less than or equal to 20 mm). The normal size of lymph nodes in young Scandinavian men was found to be less than 10 mm X 8 mm above the bifurcation, except in the area below the left renal vein to the left of the aortic midline where the normal size was found to be maximally 14 mm X 10 mm. The addition of a lymphangiographic contrast medium did not change the size of the lymph nodes significantly above the bifurcation, while changes of importance were noticed in the pelvic area. Normal size without contrast medium was found to be at the most 15 mm X 10 mm and after addition of contrast medium to the nodes 28 mm X 12 mm. The results of the CT findings in the stage II A group were not impressive but changed somewhat for the better using the new limits concerning size of retroperitoneal lymph nodes. The impact of using different limits is discussed and it is concluded that metastases in normal-sized or almost normal-sized lymph nodes will continue to be a diagnostic problem, at least when using CT.

Cell lineage labels and region-specific markers in the analysis of inductive interactions

This paper reviews work with cell lineage labels and cell-type specific markers in the analysis of inductive interactions in early amphibian development. Our results provide clear evidence for the existence of three such interactions. Mesodermal induction occurs in the early blastula and results from the action of vegetal pole cells on the animal hemisphere. At least two mesodermal rudiments are formed, one dorsal and one ventral. During the next interaction, which we call dorsalization, the ventral mesodermal rudiment becomes subdivided into several territories under the influence of the dorsal marginal zone, or organizer. Finally, during gastrulation, the involuting organizer induces neural tissue from the overlying ectoderm. This interaction is called neural induction.

Although these phenomena can readily be demonstrated under experimental conditions, direct evidence that they occur in normal development awaits an understanding of the molecular basis of induction.

Cell lineage labels and region-specific markers in the analysis of inductive interactions

This paper reviews work with cell lineage labels and cell-type specific markers in the analysis of inductive interactions in early amphibian development. Our results provide clear evidence for the existence of three such interactions. Mesodermal induction occurs in the early blastula and results from the action of vegetal pole cells on the animal hemisphere. At least two mesodermal rudiments are formed, one dorsal and one ventral. During the next interaction, which we call dorsalization, the ventral mesodermal rudiment becomes subdivided into several territories under the influence of the dorsal marginal zone, or organizer. Finally, during gastrulation, the involuting organizer induces neural tissue from the overlying ectoderm. This interaction is called neural induction. Although these phenomena can readily be demonstrated under experimental conditions, direct evidence that they occur in normal development awaits an understanding of the molecular basis of induction.

Mesoderm induction in Xenopus laevis: a quantitative study using a cell lineage label and tissue-specific antibodies

We have compared the development of the animal pole (AP) region of early Xenopus embryos in normal development, in isolation, and in combination with explants of tissue from the vegetal pole (VP) region. For the grafts and the combinations the animal pole tissue was lineage labelled with FLDx in order to ascertain the provenance of the structures formed. The normal fate of the AP region was determined by orthotopic grafts at stages 7½ (early blastula), 8 (mid blastula) and 10 (early gastrula). At later stages most of the labelled cells were found in ectodermal tissues such as epidermis, head mesenchyme and neural tube (the last from stages 7½ and 8 only). However, in stage-7½ and stage-8 grafts some of the labelled cells were also found in the myotomes and lateral mesoderm.

In isolated explants the AP region of all three stages differentiated only as epidermis assessed both histologically and by immunofluorescence using an antibody to epidermal keratin. The fate of labelled cells in AP-VP combinations was quite different and confirms the reality of mesoderm induction. In combinations made at stages 7½ and 8 the proportion of AP-derived mesoderm is substantially greater than the proportion of labelled mesoderm in the equivalent fate mapping experiments. This shows that the formation of mesoderm in such combinations is the result of an instructive rather than a permissive interaction.

The formation of mesodermal tissues in stage-7½ combinations was confirmed by using a panel of antibodies which react with particular tissues in normal tailbud-stage embryos: anti-keratan sulphate for the notochord, anti-myosin for the muscle and anti-keratin for epidermis and notochord.

Combinations made at stage 10 gave no positive cases and reciprocal heterochronic combinations between stages 7½ and 10 showed that this is the result of a loss of competence by the stage-10 AP tissue. Whereas stage-7½ AP tissue combined with stage-10 VP tissue gave many positive cases, the reciprocal experiment gave only a few.

We have also tested the regional specificity of the induction. Stage-7½ vegetal pole explants were divided into dorsal and ventral regions and then combined, separately, with stage-7½ animal poles. The dorsovegetal tissue induces ‘dorsal-type’ mesoderm (notochord and large muscle masses) while ventrovegetal tissue induces ‘ventral-type’ mesoderm (blood, mesothelium and a little muscle). We conclude that mesoderm formation in combinations is an instructive event and propose a double gradient model to explain the complex character of the response.

Mesoderm induction in Xenopus laevis: a quantitative study using a cell lineage label and tissue-specific antibodies

We have compared the development of the animal pole (AP) region of early Xenopus embryos in normal development, in isolation, and in combination with explants of tissue from the vegetal pole (VP) region. For the grafts and the combinations the animal pole tissue was lineage labelled with FLDx in order to ascertain the provenance of the structures formed. The normal fate of the AP region was determined by orthotopic grafts at stages 7 1/2 (early blastula), 8 (mid blastula) and 10 (early gastrula). At later stages most of the labelled cells were found in ectodermal tissues such as epidermis, head mesenchyme and neural tube (the last from stages 7 1/2 and 8 only). However, in stage-7 1/2 and stage-8 grafts some of the labelled cells were also found in the myotomes and lateral mesoderm. In isolated explants the AP region of all three stages differentiated only as epidermis assessed both histologically and by immunofluorescence using an antibody to epidermal keratin. The fate of labelled cells in AP-VP combinations was quite different and confirms the reality of mesoderm induction. In combinations made at stages 7 1/2 and 8 the proportion of AP-derived mesoderm is substantially greater than the proportion of labelled mesoderm in the equivalent fate mapping experiments. This shows that the formation of mesoderm in such combinations is the result of an instructive rather than a permissive interaction. The formation of mesodermal tissues in stage-7 1/2 combinations was confirmed by using a panel of antibodies which react with particular tissues in normal tailbud-stage embryos: anti-keratan sulphate for the notochord, anti-myosin for the muscle and anti-keratin for epidermis and notochord. Combinations made at stage 10 gave no positive cases and reciprocal heterochronic combinations between stages 7 1/2 and 10 showed that this is the result of a loss of competence by the stage-10 AP tissue. Whereas stage-7 1/2 AP tissue combined with stage-10 VP tissue gave many positive cases, the reciprocal experiment gave only a few. We have also tested the regional specificity of the induction. Stage-7 1/2 vegetal pole explants were divided into dorsal and ventral regions and then combined, separately, with stage-7 1/2 animal poles. The dorsovegetal tissue induces 'dorsal-type' mesoderm (notochord and large muscle masses) while ventrovegetal tissue induces 'ventral-type' mesoderm (blood, mesothelium and a little muscle). We conclude that mesoderm formation in combinations is an instructive event and propose a double gradient model to explain the complex character of the response.

Pattern regulation in fragments of Drosophila wing discs which show variable wound healing

When complementary fragments of the imaginal wing disc of Drosophila are cultured for several days prior to inducing metamorphosis, usually one fragment will regenerate while the second duplicates. It has been proposed that wound healing plays an important part in disc regulation by initiating cell proliferation and determining the mode of regulation (regeneration/duplication). To test the latter proposal 15 types of wing disc fragments were examined for variability both in the mode of wound healing and the mode of pattern regulation. Two modes of wound healing were observed, regular - the two wound edges heal with each other, and irregular - each wound edge heals with itself. When cultured separately fragments that healed regularly regenerated, while fragments that healed irregularly duplicated. This suggests that the mode of wound healing determines the mode of pattern regulation.

Analysis of embryonic induction by using cell lineage markers

Three distinct inductive interactions have been demonstrated in early embryos of Xenopus laevis: mesoderm induction, dorsalization and neural induction. The experiments were done with grafts from embryos uniformly labelled with passive cell lineage markers, either FITC-lysine-dextran (FLDx) or horseradish peroxidase (HRP), which allow the provenance of regions to be determined down to the single cell level. In each case the fate of the target tissue in the presence of the appropriate inductor was quite different from the fate in normal development.