Obstetric outcomes in Jehovah's Witnesses: case series over nine years in a London teaching hospital

OBJECTIVES

The aim of the study is to assess obstetric and fetal outcomes of Jehovah's Witnesses (JWs) mothers in an inner city teaching hospital, as well as to examine the acceptance rates of various blood fractions and blood transfusion alternatives.

METHODS

Case series to evaluate the maternal and fetal outcomes of JWs over a nine period between 2013 and 2021.

RESULTS

There were 146 pregnancies extracted from our database, of which 10 were early pregnancy losses. Data from 136 deliveries > 24 weeks' gestation were assessed, with a mean maternal age and gestational age of 30.26 (± 5.4) years and 38.7 (± 5.3) weeks, respectively. 57% had normal vaginal deliveries, 8% had instrumental births and 35% had caesarean births. Mean estimated blood loss at caesarean was 575 (± 305.6) mls, while the overall mean estimated loss was 427.8 (± 299.8) mls. Cell salvage was performed in all caesarean sections but autologous transfusion was only necessary for 26%. Consultant presence was documented in 62% of caesarean births. The mean birthweight and 5-min Apgar scores were 3.31 (± 0.05) kg and 9.1 (± 0.09), respectively. There were no maternal deaths or admissions to the adult intensive care unit and the most serious complication was a uterine rupture following a trial of scar, after which the baby required cooling for hypoxic ischaemic encephalopathy.

CONCLUSIONS

Pregnant JWs received obstetric care led by senior clinicians, with optimisation of haematinics, minimizing of blood loss at delivery and access to technology such as cell salvage.

The Atacama Rover Astrobiology Drilling Studies (ARADS) Project

With advances in commercial space launch capabilities and reduced costs to orbit, humans may arrive on Mars within a decade. Both to preserve any signs of past (and extant) martian life and to protect the health of human crews (and Earth's biosphere), it will be necessary to assess the risk of cross-contamination on the surface, in blown dust, and into the near-subsurface (where exploration and resource-harvesting can be reasonably anticipated). Thus, evaluating for the presence of life and biosignatures may become a critical-path Mars exploration precursor in the not-so-far future, circa 2030. This Special Collection of papers from the Atacama Rover Astrobiology Drilling Studies (ARADS) project describes many of the scientific, technological, and operational issues associated with searching for and identifying biosignatures in an extreme hyperarid region in Chile's Atacama Desert, a well-studied terrestrial Mars analog environment. This paper provides an overview of the ARADS project and discusses in context the five other papers in the ARADS Special Collection, as well as prior ARADS project results.

Under-Representation for Female Cancers in Commercial Auto-Segmentation Solutions and Open-Source Imaging Datasets

PURPOSE/OBJECTIVE(S)

Auto-segmentations methods to aid radiation therapy (RT) workflows have recently emerged with the increasing availability of commercial solutions for organs at risk (OARs) in addition to open-source imaging datasets that support training for new auto-segmentation algorithms. Here, we explored whether female and male cancer sites are equally represented among these solutions.

MATERIALS/METHODS

Inquiries were sent out to five major RT vendors regarding their currently available auto-segmentation solutions. Additionally, The Cancer Imaging Archive (TCIA) was screened for publicly available imaging datasets pertaining to female and male tumor sites.

RESULTS

The five commercial solutions provided a median of 103 (range: 60-120) OAR auto-segmentations of which the majority concerned the head and neck (45 (24-55)) and thorax (34 (27-43)) and were provided by all vendors (Table). Prostate as a site was also provided by all vendors and included 17 (9-20) auto-segmentations. A total of 23 publicly available TCIA imaging datasets involved the female anatomy (breast: 19; cervix: 2; ovarian: 1; uterus: 1) while 11 imaging datasets involved the male anatomy (prostate). No OARs segmentations were available for the 23 female-specific datasets while 27% of the 11 prostate datasets included segmented OARs. Three vendors and two TCIA datasets provided organs involved in the male sexual function apparatus (neurovascular bundle and penile bulb), whereas nipple or areola segmentations were not available among the commercial solutions for breast or among the TCIA breast datasets. None of the TCIA datasets or any of the five commercial solutions provided OARs for the female pelvis such as organs involved in reproduction (ovaries), sexual health (clitoris, vagina) or the cervix and uterus. Further, auto-segmentations provided for OARs trained exclusively on the male pelvis are likely inadequate for female cancers given the substantial anatomical differences between genders.

CONCLUSION

Commercial auto-segmentation solutions and open-source imaging datasets together include considerably more datasets, tumor sites and consequently more OAR auto-segmentations pertaining to male cancers compared to female cancers. Despite a 1.4 times higher incidence for female cancers (breast: 300,590; female pelvis: 114,810; male cancer: 299,540; Siegel RL et al CA Cancer J Clin 2023), auto-segmentation models are lacking, and this gender disparity is likely to lead to suboptimal care for female-specific cancers.

Pre-Brachytherapy Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) Response as Predictor of Local Control in the Definitive Treatment of Cervical Cancer

PURPOSE/OBJECTIVE(S)

Chemoradiation consisting of external beam radiotherapy (EBRT) followed by brachytherapy (BT) is the standard of care for Stage IB2-IVA cervical cancer (CC). Multi-parametric MRI (mpMRI) is a valuable tool for initial staging, treatment planning and response assessment. In this study, we aim to explore the potential of mpMRI, in particular DW-MRI, to predict overall tumor control following chemoradiation in CC.

MATERIALS/METHODS

We identified 78 consecutive patients treated with chemoradiation for FIGO IB2-IVA CC between 2012-2020, who had an MRI at baseline (MRb) and post-EBRT prior to brachytherapy boost (MRpb) that included DW-MRI (b-value = 0 and 800 s/mm2). Median age was 53 years, most patients had squamous cell carcinoma (76.9%) and advanced-stage disease (56.4% stage IIIA-IVA). Median time from completion of EBRT to MRpb was 3 days. Regions of interest (ROI) in primary tumor were delineated on DW image (b = 0 s/mm2) using ITK-SNAP software. DW-MRI data were fitted to a monoexponential model to calculate apparent diffusion coefficient (ADC) values using in-house software platform (MRI-QAMPER). MRpb mean ADC values (n = 78) and relative changes (%) in mean ADC values between MRb and MRpb (n = 64) were correlated with outcomes, including local failure (LF), regional or distant failure (RDF), and failure at any site (FAS), with death without failure as a competing risk. Median follow-up time was 45 months (95% CI 38, 53).

RESULTS

At first post treatment assessment, 72 patients (92.3%) had a complete response (CR) in the cervix and 68 patients (87.2%) had CR in all disease sites. Of patients who had CR in the cervix (n = 72), only 1 patient had local recurrence. Of patients who had CR in all disease sites, 10 later recurred (1 LF only, 1 LF&RDF, 8 RDF only). Overall, 7 patients (9%) had LF, and 19 patients (24.4%) had FAS. A higher mean ADC value in MRpb was associated with LF (HR 4.3, 95% CI 1.32, 14.6; P = 0.016), but not with RDF (P = 0.4) or FAS (P = 0.5). A higher relative change in the mean ADC value between MRb and MRpb was associated with a lower risk of LF (HR 0.94, 95% CI 0.90, 0.98; P = 0.002), but not with RDF (P = 0.8) or FAS (P = 0.4).

CONCLUSION

Treatment response as measured on prebrachytherapy DW-MRI is a significant predictor of local control in patients undergoing chemoradiation for stage IB2-IVA CC. ADC values, a quantitative imaging biomarker on MRpb may be instrumental in dose intensification/de-escalation efforts in CC.

Ionizable Lipid Nanoparticles for Therapeutic Base Editing of Congenital Brain Disease

Delivery of mRNA-based therapeutics to the perinatal brain holds great potential in treating congenital brain diseases. However, nonviral delivery platforms that facilitate nucleic acid delivery in this environment have yet to be rigorously studied. Here, we screen a diverse library of ionizable lipid nanoparticles (LNPs) via intracerebroventricular (ICV) injection in both fetal and neonatal mice and identify an LNP formulation with greater functional mRNA delivery in the perinatal brain than an FDA-approved industry standard LNP. Following in vitro optimization of the top-performing LNP (C3 LNP) for codelivery of an adenine base editing platform, we improve the biochemical phenotype of a lysosomal storage disease in the neonatal mouse brain, exhibit proof-of-principle mRNA brain transfection in vivo in a fetal nonhuman primate model, and demonstrate the translational potential of C3 LNPs ex vivo in human patient-derived brain tissues. These LNPs may provide a clinically translatable platform for in utero and postnatal mRNA therapies including gene editing in the brain.

Fetal allotransplant recipients are resistant to graft-versus-host disease

In utero hematopoietic cell transplantation (IUHCT) is an experimental treatment for congenital hemoglobinopathies, including Sickle cell disease and thalassemias. One of the principal advantages of IUHCT is the predisposition of the developing fetus toward immunologic tolerance. This allows for engraftment across immune barriers without immunosuppression and, potentially, decreased susceptibility to graft-versus-host disease (GVHD). We demonstrate fetal resistance to GVHD following T cell-replete allogeneic hematopoietic cell transplantation compared with the neonate. We show that this resistance is associated with elevated fetal serum interleukin-10 conducive to the induction of regulatory T cells (Tregs). Finally, we demonstrate that the adoptive transfer of Tregs from IUHCT recipients to neonates uniformly prevents GVHD, recapitulating the predisposition to tolerance observed after fetal allotransplantation. These findings demonstrate fetal resistance to GVHD following hematopoietic cell transplantation and elucidate Tregs as important contributors.

Amniotic fluid stabilized lipid nanoparticles for in utero intra-amniotic mRNA delivery

Congenital disorders resulting in pathological protein deficiencies are most often treated postnatally with protein or enzyme replacement therapies. However, treatment of these disorders in utero before irreversible disease onset could significantly minimize disease burden, morbidity, and mortality. One possible strategy for the prenatal treatment of congenital disorders is in utero delivery of messenger RNA (mRNA). mRNA is a nucleic acid therapeutic that has previously been investigated as a platform for protein replacement therapies and gene editing technologies. While viral vectors have been explored to induce intracellular expression of mRNA, they are limited in their clinical application due to risks associated with immunogenicity and genomic integration. As an alternative to viral vectors, safe and efficient in utero mRNA delivery can be achieved using ionizable lipid nanoparticles (LNPs). While LNPs have demonstrated potent in vivo mRNA delivery to the liver following intravenous administration, intra-amniotic delivery has the potential to deliver mRNA to cells and tissues beyond those in the liver, such as in the skin, lung, and digestive tract. However, LNP stability in fetal amniotic fluid and how this stability affects mRNA delivery has not been previously investigated. Here, we engineered a library of LNPs using orthogonal design of experiments (DOE) to evaluate how LNP structure affects their stability in amniotic fluid ex utero and whether a lead candidate identified from these stability measurements enables intra-amniotic mRNA delivery in utero. We used a combination of techniques including dynamic light scattering (DLS), transmission electron microscopy (TEM), and chromatography followed by protein content quantification to screen LNP stability in amniotic fluids. These results identified multiple lead LNP formulations that are highly stable in amniotic fluids ranging from small animals to humans, including mouse, sheep, pig, and human amniotic fluid samples. We then demonstrate that stable LNPs from the ex utero screen in mouse amniotic fluid enabled potent mRNA delivery in primary fetal lung fibroblasts and in utero following intra-amniotic injection in a murine model. This exploration of ex utero stability in amniotic fluids demonstrates a means by which to identify novel LNP formulations for prenatal treatment of congenital disorders via in utero mRNA delivery.

0422 Apocalypse Tau: The Relationship Between Inflammaging and Local Sleep Disruption in Older Adults is Mediated by Tau Burden

Introduction

Chronic inflammation in aging is independently associated with tau burden and sleep disruption, though the mechanism linking inflammation with sleep disruption remains unknown. Recent evidence associates tau burden with deficits in local expression of sleep spindles and slow wave activity (SWA). Here we test the hypothesis that age-related central inflammation disrupts local sleep by influencing tau pathology.

Methods

Cognitively asymptomatic older adults from the Wisconsin Alzheimer’s Disease Research Center underwent overnight polysomnography with high-density electroencephalography (hdEEG; 256 channels) at the University of Wisconsin-Madison (n=33, 61.9±6.7 years, 23 female). EEG data were subjected to multitaper spectral analysis (0.5-40Hz) to yield topographic maps of SWA (SWA1:0.5-1Hz, SWA2:1-4.5Hz) and spindle (sigma1:11-13Hz; sigma2:13-16Hz) power during NREM sleep. Cerebrospinal fluid assay-based measurements of YKL-40 (indicating glial activation), phosphorylated tau (Ptau), and total tau (Ttau), were correlated with SWA and sigma topographical power employing Holm-Bonferroni correction. Multiple linear regression models were implemented controlling for age, apnea-hypopnea index (AHI), and sex at significant derivations. Finally, Sobel testing was employed to assess whether tau burden mediated YKL-40-sleep associations.

Results

Age was associated with YKL-40 (r=0.53, p=0.002), and YKL-40 was associated with both Ptau (r=0.66, p<0.001) and Ttau (r=0.68, p<0.001). Correlations between sigma2 activity and both Ptau and Ttau were detected at 14 derivations, 12 of which remained significant after controlling for age, sex, and AHI. YKL-40 was associated with sigma2 power (r=-0.39, p=0.025) across derivations expressing peak significance with tau. Sobel mediation analyses indicated that both Ptau (t=-2.15, p=0.031) and Ttau (t=-2.36, p=0.018) mediated the relationship between YKL-40 and sigma2 activity at these derivations. SWA was not associated with Ttau, Ptau, or YKL-40.

Conclusion

These results suggest that age-related increases in central glial activation may disrupt local expression of fast spindles by increasing tau burden, highlighting a potential role for chronic inflammation in sleep deficits observed in aging and Alzheimer’s disease.

Support

Supported by R56 AG052698, P50AG033514

0335 Frontal Expression of NREM Sleep Oscillations are Associated with Executive Function in Children and Adolescents

Introduction

The prefrontal cortex, an area known for executive functioning (including inhibition and self-monitoring) develops during childhood and adolescents, with a pattern of posterior to anterior brain development. Slow-wave activity (SWA) in NREM sleep, tracks brain development with high SWA power migrating from occipital to frontal region as brain maturation occurs. This pilot study aimed to examine whether slow wave topography is correlated with executive function in youth.

Methods

Seventeen healthy children and adolescents (ages 11-17; 10 females) underwent overnight polysomnography (PSG) with high-density electroencephalography (hdEEG). Behavior Rating Inventory of Executive Function (BRIEF) was administered to assess executive function. SWA (SWA1: 0.5-1 Hz; SWA2: 1-4.5 Hz) and spindle (slow sigma: 11-13 Hz; fast sigma: 13-16 Hz) activity was analyzed with spectral analysis using Welch’s method. BRIEF subscales of inhibition and monitor were correlated with SWA and sigma power across all derivations, with Holm-Bonferroni correction (126 channels). Significant derivations were then controlled for sex and self-reported Tanner stage using multiple regression

Results

BRIEF-Inhibition scale (i.e., ability to repress impulsivity) and SWA1 in anterior frontal derivations were negatively correlated (R2=0.58, p=0.047 corrected). BRIEF-Monitor scale (i.e., self-perception of one’s own behavior and interpersonal awareness) was negatively correlated with fast sigma in anterior frontal derivations (R2=0.65, p=0.013 corrected). These associations were significant after controlling for sex and Tanner stage.

Conclusion

These results support the hypothesis that NREM sleep oscillations are associated with executive function and reflect changes in neuroplasticity related to “back-to-front” brain maturation. Future longitudinal studies should combine multi-modal neuroimaging of brain structure and local sleep with comprehensive assessments of executive function to evaluate the possible link between local sleep and development of higher-order cognition in frontal brain regions in youth.

Support

NCATS grant #UL1TR001414 & PERC Systems Biology Fund

Evaluating the ACS NSQIP Risk Calculator in Primary Pancreatic Neuroendocrine Tumor: Results from the US Neuroendocrine Tumor Study Group

BACKGROUND

In a changing health care environment where patient outcomes will be more closely scrutinized, the ability to predict surgical complications is becoming increasingly important. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) online risk calculator is a popular tool to predict surgical risk. This paper aims to assess the applicability of the ACS NSQIP calculator to patients undergoing surgery for pancreatic neuroendocrine tumors (PNETs).

METHODS

Using the US Neuroendocrine Tumor Study Group (USNET-SG), 890 patients who underwent pancreatic procedures between 1/1/2000-12/31/2016 were evaluated. Predicted and actual outcomes were compared using C-statistics and Brier scores.

RESULTS

The most commonly performed procedure was distal pancreatectomy, followed by standard and pylorus-preserving pancreaticoduodenectomy. For the entire group of patients studied, C-statistics were highest for discharge destination (0.79) and cardiac complications (0.71), and less than 0.7 for all other complications. The Brier scores for surgical site infection (0.1441) and discharge to nursing/rehabilitation facility (0.0279) were below the Brier score cut-off, while the rest were equal to or above and therefore not useful for interpretation.

CONCLUSION

This work indicates that the ACS NSQIP risk calculator is a valuable tool that should be used with caution and in coordination with clinical assessment for PNET clinical decision-making.

In vivo endothelial siRNA delivery using polymeric nanoparticles with low molecular weight

Dysfunctional endothelium contributes to more diseases than any other tissue in the body. Small interfering RNAs (siRNAs) can help in the study and treatment of endothelial cells in vivo by durably silencing multiple genes simultaneously, but efficient siRNA delivery has so far remained challenging. Here, we show that polymeric nanoparticles made of low-molecular-weight polyamines and lipids can deliver siRNA to endothelial cells with high efficiency, thereby facilitating the simultaneous silencing of multiple endothelial genes in vivo. Unlike lipid or lipid-like nanoparticles, this formulation does not significantly reduce gene expression in hepatocytes or immune cells even at the dosage necessary for endothelial gene silencing. These nanoparticles mediate the most durable non-liver silencing reported so far and facilitate the delivery of siRNAs that modify endothelial function in mouse models of vascular permeability, emphysema, primary tumour growth and metastasis.

Subcutaneous insulin B:9-23/IFA immunisation induces Tregs that control late-stage prediabetes in NOD mice through IL-10 and IFNgamma

AIMS/HYPOTHESIS

Subcutaneous immunisation with the 9-23 amino acid region of the insulin B chain (B:9-23) in incomplete Freund's adjuvant (IFA) can protect the majority of 4- to 6-week-old prediabetic NOD mice and is currently in clinical trials. Here we analysed the effect of B:9-23/IFA immunisation at later stages of the disease and the underlying mechanisms.

METHODS

NOD mice were immunised once s.c. with B:9-23/IFA at 5 or 9 weeks of age, or when blood glucose reached 10 mmol/l or higher. Diabetes incidence was followed in addition to variables such as regulatory T cell (Treg) induction, cytokine production (analysed by Elispot) and emergence of pathogenic CD8(+)/NRP-V7(+) cells.

RESULTS

A single B:9-23/IFA immunisation protected the majority of NOD mice at advanced stages of insulitis, but not after blood glucose reached 13.9 mmol/l. It increased Treg numbers and lost its protective effect after IFNgamma or IL-10 neutralisation, but not in the absence of IL-4. CD4(+)CD25(+) and to a lesser extent IFNgamma-producing cells from mice protected by B:9-23/IFA induced tolerance upon transfer into new NOD animals, indicating that a dominant Treg-mediated effect was operational. Reduced numbers of CD8(+)/NRP-V7(+) memory T cells coincided with protection from the disease.

CONCLUSIONS/INTERPRETATION

Protection from diabetes after B:9-23/IFA immunisation cannot be achieved once diabetes is fully established, but can be achieved at most prediabetic stages of the disease. Protection is mediated by Tregs that require IFNgamma and IL-10. These findings should provide important guidance for ongoing human trials, especially for the development of suitable T cell biomarkers.

Why me? A missing girl

Demographic imbalance created because of the declining sex ratio in India is a cause of concern to policy makers, implementers, demographers and social reformers. To take situation under control, Pre Natal Diagnostic Techniques (PNDT) Act is operational since 1996. Authors have critically reviewed the status of women and socio-cultural factors influencing their status based on data from NFHS III and census 2001 and challenges faced in the operationalisation of PNDT Act in India.

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) as a predictor of response in head and neck squamous cell carcinoma (HNSCC)

6007

Background: We wish to assess on a preliminary basis whether pretreatment DCE-MRI predicts response to chemoradiation in HNSCC. Methods: Tumor perfusion was assessed in 14 patients (median age, 56y; 13 M, 1 F; squamous cell cancer 13, poorly differentiated carcinoma 1; base of tongue 6; tonsil 6; larynx 1; nasopharynx 1) with nodal metastases (size >1 cc for DCE-MRI; N1, 3; N2a, 2; N2b, 4; N2c, 4; N3, 1; Stage III, 3; Stage IVa, 10; Stage IVb, 1) prior to platin-based concurrent chemoradiation therapy. Data were acquired on a 1.5 Tesla clinical scanner with a standard MRI protocol using a clinical contrast agent (Gd-DTPA). The two compartment model analysis measured the rate constants of the contrast agent transfer between the lesion and plasma compartments (kep) and elimination by the plasma (kel). Each patient was assigned a single MR imaging parameter of uptake slope and compartmental model (Akep) on the basis of the histogram analysis of all individually fit tumor voxels. Histogram analysis calculated the amplitude (a), width (s), and median (μ) of the distribution from the fitting procedure. Overall response was determined approximately 2–5 months post treatment. Results: DCE-MRI data showed a rapid rise in the time intensity curves for viable appearing tumor, whereas muscle showed minimal signal enhancement. The mean Akep value was higher for complete responders (CR/near CR, n = 7) than for incomplete responders (ICR, n = 7; 3 partial response, 4 no response) (12.29/min±4.09 vs 7.11/min±2.51 [P = 0.04]. The preliminary histogram analysis for the slope showed that the width and median were able to differentiate between CR and ICR, P=0.039 and P=0.013 respectively, while amplitude was not significant (P=0.150). Conclusions: These preliminary data suggest that DCE-MRI may prove to be a useful predictor of response in HNSCC patients, and thus may enhance prognostication, patient selection, and treatment outcomes.

No significant financial relationships to disclose.

Sudden cardiac arrest in a neonate with congenital adrenal hyperplasia

We describe a 6-day-old male who developed cardiac arrest due to hyperkalemia secondary to congenital adrenal hyperplasia and was successfully resuscitated. This case illustrates the importance of considering congenital adrenal hyperplasia as one of the causes of sudden cardiac arrest in a neonate. A literature review revealed only one similar case in a 3-month-old with a fatal outcome.

Complicated stent supported cerebrovascular angioplasty: case analyses and review of literature

BACKGROUND

Hemodynamic lesions of the cervicocerebral vasculature are currently being treated with stent supported percutaneous transluminal angioplasty. These procedures have met with increasing success when compared to the risks and morbidity of more invasive surgical approaches. The versatility of stent-supported angioplasty as a primary therapeutic modality is examined in the following complex cases.

CASE DESCRIPTION

We present four cases involving cervical angioplasty with emergent or adjunctive stent placement. Two cases involved the subclavian arteries, whereas the others involved the vertebral and internal carotid arteries. In our experience, complications of cervicocerebral artery angioplasty have been successfully managed by stent placement.

CONCLUSION

Our cases demonstrate the emerging role of cervical angioplasty and stent implantation as a successful therapeutic modality, highlighted in these complex cases.

Effect of pulmonary artery stenoses on the cardiopulmonary response to exercise following repair of tetralogy of Fallot

Data from exercise tests, echocardiograms, and lung perfusion scans were analyzed to determine whether the excessive minute ventilation (VE) often encountered among patients with tetralogy of Fallot is due to ventilation-perfusion mismatch secondary to branch pulmonary artery stenoses. Patients with branch PA stenoses had lower peak oxygen consumptions and higher VE during exercise than did patients without stenoses, and a strong correlation existed between the degree of pulmonary blood flow maldistribution on lung perfusion scan and the amount of excessive VE during exercise.

Expression of retinoic acid receptor beta in human renal cell carcinomas correlates with sensitivity to the antiproliferative effects of 13-cis-retinoic acid

The differentiation and growth suppressive effects of retinoic acid are mediated through retinoic acid nuclear receptors (RARs and RXRs), which are ligand-activated transcription factors. Recent data suggest that both altered and regulated expression of RARs are linked to retinoic acid response in a cell context-dependent manner. This study examined the antiproliferative effects of 13-cis-retinoic acid (cRA) on 12 renal cancer cell lines and correlated these findings with the basal and induced expression of RAR-alpha, -beta and -gamma. Eleven of 12 renal cancers that were either resistant to or only minimally inhibited by cRA did not basally express RAR-beta as determined by Northern blot analysis. In these cells, cRA treatment did not induce RAR-beta expression. In contrast, 1 of 12 cell lines (SK-RC-06) was >90% inhibited by cRA and basally expressed RARbeta. Furthermore, RAR-beta mRNA in SK-RC-06 cells was up-regulated by cRA treatment. Amplification of cDNA using PCR and RAR-beta isoform-specific primer pairs revealed that only SK-RC-06 cells expressed the RAR-beta1 isoform. Expression of RAR-alpha transcripts was abundant in all 12 cell lines examined, whereas low levels of RAR-gamma transcripts were detectable in 6 of 10 renal cancers. Expression of RAR-alpha and RAR-gamma was not affected by cRA. These data showing that the majority of renal cancer cell lines are resistant to cRA suggest that: (a) resistance to the antiproliferative action of cRA correlates with repressed RAR-beta mRNA expression; and (b) the antiproliferative effects of cRA in renal cancer cells are mediated through RAR-beta1.

Micropropagation of Sterculia urens Roxb. - an endangered tree species

An in vitro procedure for large scale multiplication of Sterculia urens Roxb. (Gum Kadaya Tree) has been developed using cotyledonary node segments. An average of 4.0 shoots per node were obtained on Murashige and Skoog's (MS) medium containing 2.0 mgl(-1) 6-benzyl amino-purine (BAP) within 21 days of initial culture. Upon subsequent subculture 16 shoots/node could be harvested every three weeks and upto three times. Sixty per cent of the shoots were successfully rooted. Rooted plantlets were transferred to plastic pots containing soil under mist house conditions before they were finally exposed to an external environment. Fifty seven per cent of the plantlets survived in nursery sheds.

Alterations in the p53 and MDM-2 genes are infrequent in clinically localized, stage B prostate adenocarcinomas

Alterations in the p53 gene have been described in a variety of human malignant neoplasms. We have examined 29 stage B prostate carcinomas for alterations in the p53 gene and for amplification of the MDM-2 gene. No evidence of mutations in the conserved exons 5 to 8 was found by polymerase chain reaction single-stranded conformation polymorphism analysis and no accumulation of p53 protein was found by immunohistochemistry. However, loss of heterozygosity at the p53 locus was observed in 11% of information cases. Amplification of the MDM-2 gene was not observed by Southern blot hybridization. In contrast, stage C and D prostate carcinomas showed accumulation of p53 protein in 33 to 66% of cases. We conclude that alterations in p53 function are infrequent in clinically localized prostate cancers but are more common in advanced cancers.

Distributed representation in the song system of oscines: evolutionary implications and functional consequences

This paper reviews the organizational principles and implications that have emerged from the analysis of HVc, a forebrain nucleus that is a major site of sensory, motor, and sensorimotor integration in the song control system of oscine passerine birds (songbirds). Anatomical, physiological, and behavioral data support the conclusion that HVc exists within a hierarchically organized system with parallel pathways that converge onto HVc. The organization of HVc is distributed and redundant, and its outputs exhibit broad divergence. A similar pattern of connectivity exists for neostriatum adjacent to HVc. This and other data support the hypothesis that the song system arose from an elaboration or duplication of pathways generally present in all birds. Spontaneous and auditory response activity is strongly correlated throughout HVc, with auditory responses exhibiting strong temporal modulation in a synchronized fashion throughout the nucleus. This suggests that the auditory representation of song is encoded in the synchronized temporal patterns of activation, and that the predominant selectivity for the individual's own song that is observed for HVc neurons results from interactions of auditory input with central pattern generators for song. Most, or all HVc neurons are recruited during singing. The auditory response and motor recruitment properties of individual HVc neurons have no simple relationship, and the spontaneous activity in HVc may build up in the seconds preceding a song. To the extent HVc participates in perceptual phenomena associated with song, production and perception are not tightly linked in adults but may be linked by shared developmental processes during periods of sensorimotor learning.