Conservative and Surgical Modalities in the Management of Pediatric Parapneumonic Effusion and Empyema: A Living Systematic Review and Network Meta-Analysis

BACKGROUND

The optimal treatment for community-acquired childhood pneumonia complicated by empyema remains unclear.

RESEARCH QUESTION

In children with parapneumonic effusion or empyema, do hospital length of stay and other key clinical outcomes differ according to the treatment modality used?

STUDY DESIGN AND METHODS

A living systematic review of randomized controlled trials (RCTs) was conducted by searching the Cochrane Central Register of Controlled Trials, Embase, Latin American and Caribbean Health Sciences Literature, Ovid MEDLINE, and Web of Science Core Collection databases. Eligible RCTs included patients aged < 18 years and compared two of the following treatment modalities: antibiotics alone, chest tube insertion with or without fibrinolytics, video-assisted thoracoscopic surgery (VATS), and decortication via thoracotomy. A network meta-analysis was performed to evaluate treatment effects on hospital length of stay (LOS), the primary outcome.

RESULTS

Eleven trials including a total of 590 patients were selected for the network meta-analysis. Compared with a chest tube alone, a chest tube with fibrinolytics, thoracotomy, and VATS were all associated with shorter LOS, with a mean difference of 5.05 days (95% CI, 2.46-7.64), 6.33 days (95% CI, 3.17-9.50), and 5.86 days (95% CI, 3.38-8.35), respectively. No substantial differences in LOS were observed between the latter three interventions. None of the 11 RCTs compared antibiotics alone vs other types of treatment. Most trials reported peri-procedural complications and the need for reintervention, but the descriptions differed significantly between trials, preventing meta-analysis. In trials reporting health care-associated costs, fibrinolytics had cost advantages compared with VATS. Short- and long-term morbidity and mortality were very low, regardless of the treatment modality.

INTERPRETATION

The results of this network meta-analysis showed that a chest tube alone was associated with a longer LOS compared with other treatment modalities. The lower cost associated with a chest tube plus fibrinolytics warrants consideration when choosing between treatment options, given similar LOS and clinical outcomes compared with the other modalities.

Short duration of parenteral antibiotics in infants with urinary tract infections

Objectives

Current guidelines by the Canadian Paediatric Society on treating urinary tract infections (UTIs) exclude infants ≤ 60 days old. There is considerable practice variability in this age group, especially around the optimal duration of parenteral antibiotics. The study aimed to assess local practice patterns, and the safety of a short course (≤3 days) of parenteral antibiotics in young infants.

Methods

In this retrospective cohort study, 95 infants (≤60 days) with confirmed UTIs were identified at British Columbia Children's Hospital. Patients receiving short (≤3 days) and long (>3 days) duration of parenteral antibiotics were compared. Outcomes of interest included urinary tract infection recurrence within 30 days, hospital length of stay (LOS), representation, and readmission.

Results

Twenty infants (21%) received a short course of parenteral antibiotics. These infants were older (median 47 days versus 28 days) and non-bacteremic. Urinary tract infection recurrence was identified in 8 patients (8%), of which 7 were treated with a long duration (P = 1.0). Patients treated with a short duration had a significantly shorter LOS, with a mean difference of 4.21 days [95% CI: 3.37 to 5.05] (P < 0.001). All five (5%) bacteremic patients were treated exclusively with parenteral antibiotics.

Conclusions

In a Canadian setting, a short course of parenteral antibiotics is safe in young, non-bacteremic infants with UTIs. Despite substantial evidence, local practice patterns suggest a tendency towards prescription of long courses, providing an opportunity for quality improvement.

Standardizing the classification of skin tears: validity and reliability testing of the International Skin Tear Advisory Panel Classification System in 44 countries

BACKGROUND

Skin tears are acute wounds that are frequently misdiagnosed and under-reported. A standardized and globally adopted skin tear classification system with supporting evidence for diagnostic validity and reliability is required to allow assessment and reporting in a consistent way.

OBJECTIVES

To measure the validity and reliability of the International Skin Tear Advisory Panel (ISTAP) Classification System internationally.

METHODS

A multicountry study was set up to validate the content of the ISTAP Classification System through expert consultation in a two-round Delphi procedure involving 17 experts from 11 countries. An online survey including 24 skin tear photographs was conducted in a convenience sample of 1601 healthcare professionals from 44 countries to measure diagnostic accuracy, agreement, inter-rater reliability and intrarater reliability of the instrument.

RESULTS

A definition for the concept of a 'skin flap' in the area of skin tears was developed and added to the initial ISTAP Classification System consisting of three skin tear types. The overall agreement with the reference standard was 0·79 [95% confidence interval (CI) 0·79-0·80] and sensitivity ranged from 0·74 (95% CI 0·73-0·75) to 0·88 (95% CI 0·87-0·88). The inter-rater reliability was 0·57 (95% CI 0·57-0·57). The Cohen's Kappa measuring intrarater reliability was 0·74 (95% CI 0·73-0·75).

CONCLUSIONS

The ISTAP Classification System is supported by evidence for validity and reliability. The ISTAP Classification System should be used for systematic assessment and reporting of skin tears in clinical practice and research globally. What's already known about this topic? Skin tears are common acute wounds that are misdiagnosed and under-reported too often. A skin tear classification system is needed to standardize documentation and description for clinical practice, audit and research. What does this study add? The International Skin Tear Advisory Panel Classification System was psychometrically tested in 1601 healthcare professionals from 44 countries. Diagnostic accuracy was high when differentiating between type 1, 2 and 3 skin tears using a set of validated photographs.

PIN1 Attenuation Improves Midface Hypoplasia in a Mouse Model of Apert Syndrome

Premature fusion of the cranial suture and midface hypoplasia are common features of syndromic craniosynostosis caused by mutations in the FGFR2 gene. The only treatment for this condition involves a series of risky surgical procedures designed to correct defects in the craniofacial bones, which must be performed until brain growth has been completed. Several pharmacologic interventions directed at FGFR2 downstream signaling have been tested as potential treatments for premature coronal suture fusion in a mouse model of Apert syndrome. However, there are no published studies that have targeted for the pharmacologic treatment of midface hypoplasia. We used Fgfr2^S252W/+ knock-in mice as a model of Apert syndrome and morphometric analyses to identify causal hypoplastic sites in the midface region. Three-dimensional geometric and linear analyses of Fgfr2^S252W/+ mice at postnatal day 0 demonstrated distinct morphologic variance. The premature fusion of anterior facial bones, such as the maxilla, nasal, and frontal bones, rather than the cranium or cranial base, is the main contributing factor toward the anterior-posterior skull length shortening. The cranial base of the mouse model had a noticeable downward slant around the intersphenoid synchondrosis, which is related to distortion of the airway. Within a skull, the facial shape variance was highly correlated with the cranial base angle change along Fgfr2 S252W mutation-induced craniofacial anomalies. The inhibition of an FGFR2 downstream signaling enzyme, PIN1, via genetic knockdown or use of a PIN1 inhibitor, juglone, attenuated the aforementioned deformities in a mouse model of Apert syndrome. Overall, these results indicate that FGFR2 signaling is a key contributor toward abnormal anterior-posterior dimensional growth in the midface region. Our study suggests a novel therapeutic option for the prevention of craniofacial malformations induced by mutations in the FGFR2 gene.

Towards an international language for incontinence-associated dermatitis (IAD): design and evaluation of psychometric properties of the Ghent Global IAD Categorization Tool (GLOBIAD) in 30 countries

BACKGROUND

Incontinence-associated dermatitis (IAD) is a specific type of irritant contact dermatitis with different severity levels. An internationally accepted instrument to assess the severity of IAD in adults, with established diagnostic accuracy, agreement and reliability, is needed to support clinical practice and research.

OBJECTIVES

To design the Ghent Global IAD Categorization Tool (GLOBIAD) and evaluate its psychometric properties.

METHODS

The design was based on expert consultation using a three-round Delphi procedure with 34 experts from 13 countries. The instrument was tested using IAD photographs, which reflected different severity levels, in a sample of 823 healthcare professionals from 30 countries. Measures for diagnostic accuracy (sensitivity and specificity), agreement, interrater reliability (multirater Fleiss kappa) and intrarater reliability (Cohen's kappa) were assessed.

RESULTS

The GLOBIAD consists of two categories based on the presence of persistent redness (category 1) and skin loss (category 2), both of which are subdivided based on the presence of clinical signs of infection. The agreement for differentiating between category 1 and category 2 was 0·86 [95% confidence interval (CI) 0·86-0·87], with a sensitivity of 90% and a specificity of 84%. The overall agreement was 0·55 (95% CI 0·55-0·56). The Fleiss kappa for differentiating between category 1 and category 2 was 0·65 (95% CI 0·65-0·65). The overall Fleiss kappa was 0·41 (95% CI 0·41-0·41). The Cohen's kappa for differentiating between category 1 and category 2 was 0·76 (95% CI 0·75-0·77). The overall Cohen's kappa was 0·61 (95% CI 0·59-0·62).

CONCLUSIONS

The development of the GLOBIAD is a major step towards a better systematic assessment of IAD in clinical practice and research worldwide. However, further validation is needed.

Electron Shock Ignition of Inertial Fusion Targets

It is shown that inertial confinement fusion targets designed with low implosion velocities can be shock-ignited using laser-plasma interaction generated hot electrons (hot-e's) to obtain high energy gains. These designs are robust to multimode asymmetries and are predicted to ignite even for significantly distorted implosions. Electron shock ignition requires tens of kilojoules of hot-e's which can be produced only at a large laser facility like the National Ignition Facility, with the laser-to-hot-e conversion efficiency greater than 10% at laser intensities ∼10^{16}  W/cm^{2}.

Direct Gingival Fibroblast/Osteoblast Transdifferentiation via Epigenetics

Alveolar bone resorption caused by trauma or periodontal diseases has represented a challenge for both dental clinicians and researchers. In this study, we evaluate the osteogenic potential of human gingival fibroblasts (HGFs) through a direct transdifferentiation from HGFs to functional osteoblasts via epigenetic modification and osteogenic signaling with bone morphogenetic protein 2 (BMP2) in vitro and in vivo. HGF treatment with 5-aza-2'-deoxycytidine (5-aza-dC) induced demethylation in the hypermethylated CpG islands of the osteogenic lineage marker genes RUNX2 and ALP, and subsequent BMP2 treatment successfully drove the fibroblasts to the osteoblasts' lineage. Cell morphological changes viewed under microscopy and alkaline phosphatase (ALP) and alizarin red S (ARS) staining confirmed the osteoblastic change mediated by epigenetic modification as did real-time polymerase chain reaction (PCR), methylation-specific PCR (MSP), and chromatin immunoprecipitation (ChIP) assay, which demonstrated the altered methylation patterns in the RUNX2 and ALP promoter regions and their effect on gene expression. Furthermore, micro-computed tomography (CT) analysis of in vivo mouse cell transplantation experiments showed high-density signal in the epigenetically modified HGF group; in addition, a significant amount of bone formation was observed in the transplanted material using hematoxylin and eosin (H&E) staining as well. Collectively, our results indicate that epigenetic modification permits the direct programming of HGFs into functional osteoblasts, suggesting that this approach might open a novel therapeutic avenue in alveolar bone regeneration.

Clinical and imaging experience with yttrium-90 microspheres in the management of unresectable liver tumours

INTRODUCTION

Selective internal radiation therapy (SIRT) is emerging as a new therapeutic modality in recent years for management of non-resectable hepatic malignancies. Our experience in clinical application of this treatment is reported here.

MATERIAL AND METHODS

From June 2004, patients whose liver tumours were no longer amenable for any conventional treatment with either chemotherapy or surgery were considered for yttrium-90 microspheres treatment after discussion at our multidisciplinary meeting. A pre-treatment planning was carried out with visceral angiography and technetium-99m macroaggregated albumin (MAA) for assessment of both tumour volume and extrahepatic shunting in addition to a baseline PET and CT scans, respectively. Two weeks later, a second visceral angiogram was performed to deliver the calculated dosage of microspheres into the arterial system supplying the tumour. Patients were then followed up with tumour markers, repeat PET and CT scans of abdomen at 6 weeks and 3 monthly thereafter.

RESULT

Twenty-one patients (F=11, M=10; age range 40-75 years, mean=58 years) received yttrium-90 microspheres consisting of liver metastases from colorectal primary (n=10) and non-colorectal primaries (n=8), and primary liver tumours (n=3). One patient received 2 treatments. The mean administered activity of microspheres delivered was 1.9 GBq (range 1.2-2.5 GBq). Injection of microspheres had no immediate effect on either clinical haematology or liver function tests. At follow-up, 86% of patients showed decreased activity on PET scan at 6 weeks (p=0.01). The mean pre-treatment SUV was 12.2+/-3.7 and the mean post-treatment SUV was 9.3+/-3.7, indicating a significant improvement measured with PET activity. Only 13% showed a reduction in the size of tumour on CT scan. For patients with colorectal liver metastases, there was no significant reduction in CEA level (127+/-115 vs 75+/-72 micro/l, p=0.39). Complications were seen in 4 patients (19%) including radiation hepatitis (n=2), cholecystitis (n=1) and duodenal ulceration (n=1). All resolved without surgical intervention. Seven patients died at follow-up from progressive extrahepatic disease (33%).

CONCLUSION

SIRT should be considered for patients with advanced liver cancer. It has a significant effect on liver disease in the absence of extrahepatic disease. PET imaging has an integral role in the assessment of patients treated with yttrium-90 SIR-Spheres.

Trapped electromagnetic modes and scaling in the transmittance of perforated metal films

We describe measurements and simulations of the enhanced transmittance by subwavelength hole arrays in silver films. The array period and hole size are systematically varied to give peak transmittances at wavelengths spanning a factor of 14. The spectra coincide when scaled using the array geometry and substrate refractive index alone, thus showing no significant dependence on the dielectric function of the metal. We argue that the spectra can be explained by interference of diffractive and resonant scattering. The resonant contribution comes from electromagnetic modes trapped in the film vicinity.

Chronic lithium treatment of B lymphoblasts from bipolar disorder patients reduces transient receptor potential channel 3 levels

Chronic lithium treatment of B-lymphoblast cell lines (BLCLs) from bipolar-I disorder (BD-I) patients and healthy subjects ex vivo attenuates agonist- and thapsigargin-stimulated intracellular calcium (Ca(2+)) responses. As these findings suggest that chronic lithium treatment modifies receptor (ROCE) and/or store-operated Ca(2+) entry (SOCE) mechanisms, we determined whether chronic lithium treatment of BLCLs modified the expression of two members of the transient receptor potential channels (TRPC1 & 3), which participate in ROCE/SOCE. Chronic lithium treatment significantly reduced BLCL TRPC3 immunoreactivity (repeated-measures ANOVA, P=0.00005), with interaction effects of diagnosis (P=0.037) and sex (P=0.040). The lithium-induced decrease was greatest in BLCLs from female BD-I patients compared with those from healthy females (-27%) and with vehicle-treated BLCLs from female BD-I patients (-33%). However, lithium treatment did not affect TRPC1 and 3 mRNA levels, and TRPC1 immunoreactivity. Downregulation of TRPC3 may be an important mechanism by which lithium ameliorates pathophysiological Ca(2+) disturbances as observed in BD.

Is sildenafil failure in men after radical retropubic prostatectomy (RRP) due to arterial disease? Penile duplex Doppler findings in 174 men after RRP

Sildenafil is frequently the first-line treatment for post-radical retropubic prostatectomy (RRP) erectile dysfunction (ED) with maximum treatment satisfaction rates of 43%-80%. The etiology of erectile dysfunction after RRP has been attributed to psychogenic, vascular, veno- occlusive or nerve injury causes. The purpose of this study was to gain insight into the penile duplex Doppler arterial parameters in men with ED after RRP who failed sildenafil. The purpose was to assess whether sildenafil failure after RRP is associated with underlying corporal arterial disease. A total of 174 consecutive men presenting with sildenafil refractory ED after nerve-sparing RRP underwent color duplex penile Doppler evaluation with vasoactive injection. Mean age was 59.6 y and mean time from surgery was 11.6 months. Some 81% (141/174) of the men had no pre-operative ED (PED). Significant differences in penile duplex Doppler parameters for arterial disease were seen between men with and without PED. In men without PED, 19% (27/141) manifested arterial insufficiency. However, in men with PED, 50% (16/33) demonstrated arterial disease. Nerve sparing status did not affect the presence of arterial disease. Sildenafil refractory erectile dysfunction after RRP in men without PED is not predominantly associated with penile Doppler parameters consistent with arterial insufficiency.

Antiproliferative B cell translocation gene 2 protein is down-regulated post-transcriptionally as an early event in prostate carcinogenesis

B cell translocation gene 2 (BTG2) is a p53 target that negatively regulates cell cycle progression in response to DNA damage and other stress. The objective of this study was to examine the expression, regulation and tumor suppressor properties of BTG2 in prostate cells. By immunohistochemistry BTG2 protein was detected in approximately 50% of basal cells in benign glands from the peripheral zone of the human prostate. BTG2 was expressed in all hyperproliferative atrophic peripheral zone lesions examined (simple atrophy, post-atrophic hyperplasia and proliferative inflammatory atrophy), but was undetectable or detectable at very low levels in the hyperproliferative epithelial cells of HGPIN and prostate cancer. BTG2 mRNA was detected in non-malignant prostate epithelial (PE) cells and in LNCaP cells, but not in PC-3 cells, consistent with p53-dependent regulation. In PE cells BTG2 protein was detected in areas of cell confluence by immunohistochemistry. BTG2 protein in LNCaP cells was undetectable by immunohistochemistry but was detected by immunoblotting at 8- to 9-fold lower levels than in PE cells. BTG2 protein levels were shown to be regulated by the ubiquitin-proteosome system. Forced expression of BTG2 in PC-3 cells was accompanied by a decreased rate of cell proliferation and decreased tumorigenicity of these cells in vivo. Taken together, these findings suggest that BTG2 functions as a tumor suppressor in prostate cells that is activated by cell quiescence, cell growth stimuli as part of a positive feedback mechanism and in response to DNA damage or other cell stress. The low steady-state levels of BTG2 protein in HGPIN and prostate cancer, a potential consequence of increased proteosomal degradation, may have important implications in the initiation and progression of malignant prostate lesions. Furthermore, these findings suggest that a significant component of the p53 G(1) arrest pathway might be inactivated in prostate cancer even in the absence of genetic mutations in p53.

Prostate adenocarcinoma presenting as a large supraclavicular mass

Metastatic prostate cancer is classically associated with bony or pelvic lymphatic metastasis. This case review represents an unusual case of prostate cancer presenting with a large left supraclavicular neck mass.

Physical activity as a mediator between dyspnea and fatigue in patients with chronic obstructive pulmonary disease

A cross-sectional design was used to examine the mediating effect of physical activity between dyspnea and fatigue in patients with chronic obstructive pulmonary disease (COPD). Dyspnea was measured using a vertical visual analogue scale, fatigue using the Profile of Mood States-Fatigue subscale, and physical activity using the 6-minute-walk (6MW) test. A convenience sample of 17 male and 22 female patients with COPD provided data for analysis. The sample was characterized by relatively high forced expiratory volume in 1 second (FEV1) of predicted normal values, indicating mild lung impairment and high mean levels of fatigue and dyspnea. Controlling for age and FEV1, dyspnea, physical activity, and fatigue were significantly interrelated. Results of the regression analysis suggested the mediating function of physical activity between dyspnea and fatigue. Limitations and suggestions for practice and future research are presented.

A pilot study to examine the relationships of dyspnoea, physical activity and fatigue in patients with chronic obstructive pulmonary disease

A descriptive-correlational design was used to examine the relationships between dyspnoea, physical activity, and fatigue in patients with chronic obstructive pulmonary disease (COPD). Lazarus and Folkman's theory of stress, appraisal, and coping provided a framework to guide the study. Dyspnoea was measured by a vertical visual analogue scale, fatigue by the Fatigue subscale of the Profile of Mood States, and physical activity by the six-minute walk (6 MW) test and an open-ended question. A convenience sample of seven male and 15 female patients with COPD provided data for analysis. The sample was characterized by relatively high forced expiratory volume in one second (FEV1) indicating mild lung impairment and high mean levels of fatigue and dyspnoea. No significant gender difference was found in the ratings of dyspnoea and fatigue and the 6 MW distance. Dyspnoea, physical activities, and fatigue were all significantly inter-related (P < 0.001). Results indicated that the higher the dyspnoea scores, the shorter the 6 MW distance walked, and the higher the fatigue scores. Limitations and suggestions for nursing practice and future research are presented.

Protein synthesis, DNA degradation, and morphological changes during programmed cell death in labial glands of Manduca sexta

Labial glands of the tobacco hornworm Manduca sexta (Lepidoptera: Sphingiidae, homologues of Drosophila salivary glands, undergo programmed cell death (PCD) in a 4-day period during larva-to-pupa metamorphosis. The programmed death of the labial gland was examined by electron microscopy and measurement of protein synthesis as well as measurement of DNA synthesis, end-labeling of single strand breaks, and pulsed-field gel electrophoresis. One of the earliest changes observed is a sharp drop in synthesis of most proteins, coupled with synthesis of a glycine-rich protein, reminiscent of silk-like proteins. From a morphological standpoint, during the earliest phases the most prominent changes are the formation of small autophagic vacuoles containing ribosomes and an apparent focal dissolution of the membranes of the endoplasmic reticulum, whereas later changes include differing destruction at the lumenal and basal surfaces of the cell and erosion of the basement membrane. By the fourth day of metamorphosis, individual cells become rapidly vacuolated in a cell-independent manner. In the vacuolated cells on day 3, chromatin begins to coalesce. It is at this period that unequivocal nucleosomal ladders are seen and end-labeling in situ or electrophoretic techniques document single on double-strand breaks, respectively. DNA synthesis ceases shortly after the molt to the fifth instar, as detected by incorporation of tritiated thymidine and weak TUNEL labeling. Large size fragments of DNA are seen shortly after DNA synthesis ceases and thence throughout the instor, raising the possibility of potential limitations built into the cells before their final collapse.

Primary aldosteronism caused by unilateral adrenal hyperplasia

In the hypertensive population, primary aldosteronism has been reported to have a prevalence of 0.1% to 2%, with the main causes being aldosterone-producing adenomas and bilateral hyperplasia. However, there is a third rare entity, called unilateral adrenal hyperplasia, that contributes to primary aldosteronism. Unilateral hyperplasia and primary aldosteronism are the subjects of this case review.

Audio and visual stimulation reduces patient discomfort during screening flexible sigmoidoscopy

OBJECTIVE

Despite current recommendations calling for regular screening flexible sigmoidoscopies over the age of 50, only a small percentage of the population have regular examinations. Improving patient tolerance of flexible sigmoidoscopies could therefore increase patient compliance with these recommended guidelines. The aim of this study was to determine whether audio and visual stimulation reduces discomfort during flexible sigmoidoscopy and whether the effects of the stimulation are secondary to distraction.

METHODS

A total of 37 patients undergoing routine screening flexible sigmoidoscopy were randomized to receive no intervention, audio stimulation alone, or audio and visual stimulation. Patient discomfort ratings and affect states were measured prior to and immediately following flexible sigmoidoscopy using a visual analogue scale and the Stress Symptom Ratings (SSR) ratings.

RESULTS

Patients receiving audio and visual intervention had lower abdominal discomfort ratings (7.1 +/- 1.4) than patients receiving audio stimulation (9.5 +/- 1.3) or no intervention (10.8 +/- 1.6) (p < 0.05). Patients receiving audio and visual intervention also had higher arousal (7.3 +/- 0.4) and attention (9.2 +/- 0.2) ratings than patients receiving no intervention (6.1 +/- 0.4 and 6.2 +/- 0.7, respectively) (p < 0.05). Anxiety and anger ratings, on the other hand, were significantly lower in patients receiving audio and visual intervention (2.5 +/- 0.4, 1.4 +/- 0.3, respectively) than patients receiving no intervention (4.4 +/- 0.6, 3.6 +/- 0.7).

CONCLUSION

Audio and visual stimulation reduces abdominal discomfort associated with flexible sigmoidoscopy. This effect appears to be due to distraction.

Specification of the hindbrain fate in the zebrafish

We determine the timing of neural commitment by hindbrain tissue in the zebrafish using microsurgical transplantation. When transplanted at shield stage to the ventral side of the embryo, presumptive hindbrain cells are not committed, as they can adapt to their environment and give rise to epidermis. In contrast, when transplanted at 80% epiboly, hindbrain cells retain their neural fate and express neural-specific antigens. Moreover, they are able to maintain regional fate, as is evident by the expression of the hindbrain-specific marker, Krox20. In addition, we observe that committed hindbrain tissues are able to induce presumptive ventral epidermis to form neural crest derivatives, otic vesicles, and neural tissues. We propose that hindbrain progenitors have acquired regional identity as a group at 80% epiboly even before making vertical contact with axial mesoderm. These results suggest that planar induction may constitute a significant component in the zebrafish neural patterning pathway.

Income, language, and citizenship status: factors affecting the health care access and utilization of Chinese Americans

This article reports the results of a randomly administered interview of 1,808 Chinese American residents of San Francisco. The study examines income, language, and citizenship status and their effect on the use of health care services by this population. The articles discusses the implications of the findings for low-income and uninsured individuals, particularly people of immigrant status, and concludes with suggestions for local health care planners and advocates.

Specification of the zebrafish nervous system by nonaxial signals

The organizer of the amphibian gastrula provides the neurectoderm with both neuralizing and posteriorizing (transforming) signals. In zebrafish, transplantations show that a spatially distinct transformer signal emanates from tissues other than the organizer. Cells of the germring (nonaxial mesendoderm) posteriorized forebrain progenitors when grafted nearby, resulting in an ectopic hindbrain-like structure; in contrast, cells of the organizer (axial mesendoderm) caused no posterior transformation. Local application of basic fibroblast growth factor, a candidate transformer in Xenopus, caused malformation but not hindbrain transformation in the forebrain. Thus, the zebrafish gastrula may integrate spatially distinct signals from the organizer and the germring to pattern the neural axis.

Murine coronavirus packaging signal confers packaging to nonviral RNA

Studies of defective interfering (DI) RNAs of the murine coronavirus mouse hepatitis virus (MHV) suggest that a 69-nucleotide-long packaging signal is necessary for MHV genomic RNA packaging into MHV particles. In this study we showed that when RNA transcripts that consisted of a non-MHV sequence and the packaging signal were expressed in MHV-infected cells, they were packaged into MHV particles. Those RNA transcripts that lacked the packaging signal or those containing a mutated packaging signal did not package efficiently. Thus, the presence of the packaging signal was sufficient for RNA packaging into MHV particles.

Management of acute myocardial infarction in Auckland

AIM

To analyse the utilisation of therapies in coronary care units for patients with acute myocardial infarction.

METHODS

An evaluation form was completed prospectively by a designated nurse in each coronary care unit of the four Auckland hospitals in 1993.

RESULTS

One thousand and eighty one patients who were admitted with definite or probable acute myocardial infarction had a coronary care unit stay of 63.4 (SD 49.3) hours, and hospital stay of 7.3 (5.1) days. The mortality for definite myocardial infarction was 13.7% (< 70 years 7.1%). Coronary angiography was performed on 10% of patients during their hospital admission, and 4.9% underwent revascularisation. Thrombolytic therapy was administered to 52% (495/948) of patients with definite infarction and 4% had contraindications. Patients aged > or = 70 years (47% vs 55% p = 0.02) or diabetics (46% vs 56%, p = 0.04) were less likely to receive thrombolysis. The utilisation of aspirin and oral beta-blockers was 86% and 40%, respectively, in patients with definite infarction and both were used less frequently in patients > or = 70 years. Intravenous beta-blockers were administered to < 1% of patients. Angiotensin converting enzyme (ACE) inhibitors were prescribed in 21%, intravenous or long acting nitrates in 41% and calcium antagonists in 14%; the latter two therapies were used more frequently in patients > or = 70 years. There was no evidence of gender or ethnic bias for either investigation or treatment.

CONCLUSION

On the basis of results of recent clinical trials, there may be under utilisation of some treatments for acute myocardial infarction including aspirin, thrombolytic therapy, beta-blockers and ACE inhibitors, while calcium antagonists may be over used.

Programmed cell death in the tobacco hornworm, Manduca sexta: alteration in protein synthesis

The metamorphic death of the labial glands of the tobacco hornworm, Manduca sexta, occurs during a 4 day period during larva-to-pupa metamorphosis. The earliest changes marking the death of the cell, all occurring on the first day, are a sharp drop in protein synthesis, coupled with the selective survival or upregulation of a few messages. An early rearrangement of the rough endoplasmic reticulum is presumably related to the generalized decrease in protein synthesis. Lysosomal acid phosphatase also begins to increase very early, and ultimately the bulk of the cytoplasm is destroyed in autophagic vacuoles, but activation of lysosomes does not account for the decreased rate of synthesis. The mechanism by which most protein synthesis is depressed remains under investigation.

Order and coherence in the fate map of the zebrafish nervous system

The zebrafish is an excellent vertebrate model for the study of the cellular interactions underlying the patterning and the morphogenesis of the nervous system. Here, we report regional fate maps of the zebrafish anterior nervous system at two key stages of neural development: the beginning (6 hours) and the end (10 hours) of gastrulation. Early in gastrulation, we find that the presumptive neurectoderm displays a predictable organization that reflects the future anteroposterior and dorsoventral order of the central nervous system. The precursors of the major brain subdivisions (forebrain, midbrain, hindbrain, neural retina) occupy discernible, though overlapping, domains within the dorsal blastoderm at 6 hours. As gastrulation proceeds, these domains are rearranged such that the basic order of the neural tube is evident at 10 hours. Furthermore, the anteroposterior and dorsoventral order of the progenitors is refined and becomes aligned with the primary axes of the embryo. Time-lapse video microscopy shows that the rearrangement of blastoderm cells during gastrulation is highly ordered. Cells near the dorsal midline at 6 hours, primarily forebrain progenitors, display anterior-directed migration. Cells more laterally positioned, corresponding to midbrain and hindbrain progenitors, converge at the midline prior to anteriorward migration. These results demonstrate a predictable order in the presumptive neurectoderm, suggesting that patterning interactions may be well underway by early gastrulation. The fate maps provide the basis for further analyses of the specification, induction and patterning of the anterior nervous system, as well as for the interpretation of mutant phenotypes and gene-expression patterns.

Malignant transformation of hpv-immortalized human oral keratinocytes by chemical carcinogens

We previously immortalized primary human oral keratinocytes by transfection with cloned human papillomavirus type 16 (HPV-16) DNA and established a cell line, human oral keratinocytes-16B (HOK-16B). This line contained intact HPV-16 DNA in an integrated form, expressed viral genes, and demonstrated an indefinite life span. However, the cells proliferated only in keratinocyte growth medium containing a low level of calcium and were not tumorigenic in nude mice. To develop an in vitro multistage model suitable for the study of human oral carcinogenesis and to investigate the molecular mechanisms of cell transformation, the HOK-16B cells were exposed to either benzo(a)pyrene [B(a)P] or 7,12-dimethylbenz(a)anthracene (DMBA). Two chemically transformed cell colonies, one from B(a)P exposure and the other from DMBA treatment, were isolated. These cell lines proliferated well in Dulbecco's minimum essential medium containing a physiological level of calcium, demonstrated anchorage-independent growth, and developed tumors in nude mice. They contained integrated HPV-16 sequences and expressed higher levels of epidermal growth factor receptor (EGFR) and c-myc transcripts compared to the parental cells. Similar to their immortalized parental cells, the chemically transformed cells also contained lower levels of p53 protein and transforming growth factor-beta (TGF-beta) transcripts than normal human oral keratinocytes. These results indicate that malignant transformation of oral keratinocytes can be caused by a sequential combined effect of high-risk HPV and chemical carcinogens. It also demonstrates that overexpression of viral E6/E7, EGFR and c-myc messages, together with the down-regulation of TGF-beta mRNA and the inactivation of p53 gene, may be associated with the malignant conversion of HPV-immortalized cells.

Fate maps of the zebrafish embryo

In the past few years, we have seen a surge of interest in the zebrafish as a model system for the study of embryonic induction and patterning. This review summarizes our current knowledge of the organization of zebrafish fate maps during early development. Recent advances have addressed the relationship between early cleavage planes and the future dorsal axis, the pattern of cell mixing during blastula and gastrula stages, and the morphogenesis of the trunk neural keel. In addition, refined fate maps have become available for the embryonic shield, the central nervous system, and the heart. In combination with recent advances in molecular and genetic manipulations, these fate maps set the stage for new, more incisive, experimental approaches.