A comparison of gastric gas volumes measured by computed tomography after high-flow nasal oxygen therapy or conventional facemask ventilation. Anaesthesia 2021;76:1184-1189. [PMID: 33651914 DOI: 10.1111/anae.15433]

High-flow nasal oxygen therapy is increasingly used to improve peri-intubation oxygenation. However, it is unknown whether it may cause or exacerbate insufflation of gas into the stomach. High-flow nasal oxygen therapy is now standard practice in our hospital for adult patients undergoing percutaneous thermal ablation of liver cancer under general anaesthesia with tracheal intubation. We compared gastric gas volumes measured from computed tomography images that had been acquired immediately after intubation in two series of patients: 50 received peri-intubation high-flow nasal oxygen therapy and another 50 received conventional facemask pre-oxygenation and ventilation before intubation and before high-flow nasal oxygen therapy became standard practice in our unit. Median (IQR [range]) gastric gas volume was 24.0 (14.2-59.9 [3-167]) cm³ in the high-flow nasal oxygen therapy group and 23.8 (12.6-38.8 [0-185]) cm³ in the facemask group. There was no difference between the two groups in the volume of gastric gas measured by computed tomography imaging (Mann-Whitney U-test, U = 1136, p = 0.432, n₁  = n₂  = 50). Our results demonstrate that a small volume of gastric gas is commonly present after induction of anaesthesia, but that the use of peri-intubation high-flow nasal oxygen therapy for pre-oxygenation and during apnoea does not increase this volume compared with conventional facemask pre-oxygenation and ventilation. This is clinically relevant, as high-flow nasal oxygen therapy is increasingly being used in a peri-intubation context and in patients at higher risk of aspiration.

Does perfusion CT play a role in the evaluation of percutaneous microwave-ablated lung tumours?

AIM

To assess the clinical utility of perfusion computed tomography (pCT) parameters in microwave ablation (MWA) of lung tumours.

MATERIALS AND METHODS

Patients were included who had primary or metastatic lung tumours and underwent pCT studies immediately pre- and post-MWA. Perfusion maps of the tumours were constructed using CT perfusion software (GE, Milwaukee, WI, USA). Regions of interest were drawn on sequential axial sections to extract the pCT parameters, blood volume (BV), average blood flow (BF), and mean transit time (MTT) from the entire tumour volume. Direct visualisation of perfusion maps were performed by two experienced readers blinded to outcome. Data were analysed using the Mann-Whitney test.

RESULTS

Thirty-one patients with 34 lung tumours had follow-up data at 12 months. The median tumour diameter was 19 mm (10-52 mm). Seven patients developed local tumour progression (LTP) at 12 months. There was no statistical difference between patients with LTP and complete treatment based on quantitative pCT parameters. Using radiologist visualisation of perfusion maps, there was moderate agreement between the two readers (kappa coefficient 0.53) with a combined 96% sensitivity, 62% specificity, 91% positive predictive value, and 80% negative predictive value.

CONCLUSION

Quantitative pCT parameters do not help differentiate between LTP and complete treatment, but subjective analysis of perfusion maps may be a useful assessment tool for identifying treatment adequacy potentially enabling identification of areas requiring further treatment at the time of the procedure.

Transanal endoscopic microsurgery for rectal cancer

Since its introduction in the 1980s, total mesorectal excision (TME) has been the standard surgical technique for treating rectal cancer. This procedure involves removing the rectum and the surrounding envelope of fat along the plane of the mesorectal fascia. Resecting this embryological unit reduces the local recurrence rate by removing all local lymph nodes, including those with occult metastatic disease; however, this surgery is associated with mortality and morbidity. Complications include incontinence for patients given an anastomosis, long-term stoma formation, and sexual and bladder dysfunction. Local excision of rectal cancer using the transanal endoscopic microsurgery (TEM) technique is associated with fewer complications, and therefore, is used as an alternative in specific circumstances. We outline the technique, its indications, imaging appearances and complications.

Field evaluation of the response of Aedes albopictus (Stegomyia albopicta) to three oviposition attractants and different ovitrap placements using black and clear autocidal ovitraps in a rural area of Same, Timor-Leste

Known oviposition attractants or stimulants were compared, singly and in combination, using inexpensive autocidal ovitraps designed to trap emerging adults, in a rural area of Timor-Leste during the dry season. In this area, the dengue vector Aedes albopictus (Stegomyia albopicta) Skuse (Diptera: Culicidae) was abundant, but Aedes aegypti (Stegomyia aegypti) L. was not detected. The attractants were: (a) a compound found in Aedes eggs (dodecanoic acid); (b) components of nitrogen, phosphorous and potassium-based (NPK) fertilizer, and (c) infusions of discarded cigarette butts. A solution of ammonium phosphate and potassium nitrate was significantly more attractive to gravid Ae. albopictus than water only. Dodecanoic acid and cigarette butt infusions were not significantly more attractive than the control; however, they attracted various other Diptera and many non-culicid larvae developed in ovitraps in which these substances were used; thus, the presence of eggs or larvae of other species may have deterred Aedes oviposition. Significantly more Aedes eggs were found in ovitraps under vegetation than in ovitraps placed inside houses or against external walls. Clear-sided ovitraps in which black mesh was placed over a black ring floating on the water surface collected significantly fewer eggs than black ovitraps with identically placed mesh and rings.

High-frequency jet ventilation under general anesthesia facilitates CT-guided lung tumor thermal ablation compared with normal respiration under conscious analgesic sedation

PURPOSE

To determine whether technical difficulty of computed tomography (CT)-guided percutaneous lung tumor thermal ablations is altered with the use of high-frequency jet ventilation (HFJV) under general anesthesia (GA) compared with procedures performed with normal respiration (NR) under conscious sedation (CS).

MATERIALS AND METHODS

Thermal ablation treatment sessions performed with NR under CS or HFJV under GA with available anesthesia records and CT fluoroscopic images were retrospectively reviewed; 13 and 33 treatment sessions, respectively, were identified. One anesthesiologist determined the choice of anesthesiologic technique independently. Surrogate measures of procedure technical difficulty--time duration, number of CT fluoroscopic acquisitions, and radiation dose required for applicator placement for each tumor--were compared between anesthesiologic techniques. The anesthesiologist time and complications were also compared. Parametric and nonparametric data were compared by Student independent-samples t test and χ(2) test, respectively.

RESULTS

Patients treated with HFJV under GA had higher American Society of Anesthesiologists classifications (mean, 2.66 vs 2.23; P = .009) and smaller lung tumors (16.09 mm vs 27.38 mm; P = .001). The time duration (220.30 s vs 393.94 s; P = .008), number of CT fluoroscopic acquisitions (10.31 vs 19.13; P = .023), and radiation dose (60.22 mGy·cm vs 127.68 mGy·cm; P = .012) required for applicator placement were significantly lower in treatment sessions performed with HFJV under GA. There was no significant differences in anesthesiologist time (P = .20), rate of pneumothorax (P = .62), or number of pneumothoraces requiring active treatment (P = .19).

CONCLUSIONS

HFJV under GA appears to reduce technical difficulty of CT-guided percutaneous applicator placement for lung tumor thermal ablations, with similar complication rates compared with treatment sessions performed with NR under CS. The technique is safe and may facilitate treatment of technically challenging tumors.

Baseline corticosterone in wintering marine birds: methodological considerations and ecological patterns

Previous studies have related levels of plasma corticosterone (CORT) of seabirds to variation in foraging conditions during the breeding period, but it is unclear whether similar relationships between foraging conditions and baseline CORT exist during other life stages. We validated methods for identifying baseline CORT of lethally sampled birds and assessed variation in baseline CORT relative to winter habitat conditions. We collected free-living white-winged scoters (Melanitta fusca) at four wintering sites during December and February. We found increasing CORT values beyond 3 min after time since flush (the duration between initial flush and death), presumably reflecting acute stress responses. Our results demonstrate that it is possible to obtain baseline CORT from lethally sampled birds if the time from initial flush until death is measured. Our study sites varied appreciably in exposure to wind and waves, predation danger, diving depths, and the fraction of preferred foods in scoter diets. Despite these habitat differences, baseline CORT did not vary across sites or winter periods. We interpret this lack of variation as evidence that birds select wintering areas where they can successfully manage site-specific costs and maintain physiological homeostasis.

Effects of pretraining and water temperature on female rats' performance in the Morris water maze

The water maze is a complex spatial task that requires the coordination of multiple systems to perform efficiently. Various factors have been shown to influence performance in this task, including motivational state and prior experience. Although a consistent sex difference has been observed in acquiring the water maze in rats, the contribution of the various factors in female rat performance has not been fully assessed. Therefore, the current study tested the effects of motivation as manipulated by water temperature of the maze and prior experience in the maze on the performance of female rats. It was hypothesized that females pretrained in the maze would perform better than those without exposure to the water maze, regardless of water temperature, but in naïve rats, colder water would improve performance as shown previously in male rats. For pretraining, female rats were taught to find a visible platform in cold (19 °C, 4 trials on one day) and warm (25 °C, 4 trials on one day) water before acquisition trials, with the order of the water temperature randomly assigned. Control rats were not given any training and were naïve to the water maze procedure. Pretrained and control rats were then tested to locate a hidden platform in either cold or warm water for 5 consecutive days. Overall, pretraining had a significant effect on distance, latency, and directness of path to the platform. Water temperature did not show a significant effect on any measure or a significant interaction with pretraining. Thus, while our hypothesis that pretraining would improve performance was supported, the results did not support the prediction that water temperature would also significantly influence performance. These results show that non-spatial pretraining can critically improve the performance of females in acquiring a place strategy for the hidden platform, irrespective of water temperature.

A computer-aided algorithm to quantitatively predict lymph node status on MRI in rectal cancer

OBJECTIVE

The aim of this study was to demonstrate the principle of supporting radiologists by using a computer algorithm to quantitatively analyse MRI morphological features used by radiologists to predict the presence or absence of metastatic disease in local lymph nodes in rectal cancer.

METHODS

A computer algorithm was developed to extract and quantify the following morphological features from MR images: chemical shift artefact; relative mean signal intensity; signal heterogeneity; and nodal size (volume or maximum diameter). Computed predictions on nodal involvement were generated using quantified features in isolation or in combinations. Accuracies of the predictions were assessed against a set of 43 lymph nodes, determined by radiologists as benign (20 nodes) or malignant (23 nodes).

RESULTS

Predictions using combinations of quantified features were more accurate than predictions using individual features (0.67-0.86 vs 0.58-0.77, respectively). The algorithm was more accurate when three-dimensional images were used (0.58-0.86) than when only middle image slices (two-dimensional) were used (0.47-0.72). Maximum node diameter was more accurate than node volume in representing the nodal size feature; combinations including maximum node diameter gave accuracies up to 0.91.

CONCLUSION

We have developed a computer algorithm that can support radiologists by quantitatively analysing morphological features of lymph nodes on MRI in the context of rectal cancer nodal staging. We have shown that this algorithm can combine these quantitative indices to generate computed predictions of nodal status which closely match radiological assessment. This study provides support for the feasibility of computer-assisted reading in nodal staging, but requires further refinement and validation with larger data sets.

Long-term changes in reward-seeking following morphine withdrawal are associated with altered N-methyl-D-aspartate receptor 1 splice variants in the amygdala

The NR1 subunit of the NMDA receptor can be alternatively spliced by the insertion or removal of the N1, C1, C2, or C2' regions. Morphine dependence and withdrawal were previously demonstrated to lower N1 and C2' in the accumbens and lower N1, C1, and C2' in the amygdala (AMY). Withdrawal has also been demonstrated to increase motivational and anxiety/stress behaviors in rats. We tested the hypothesis that NR1 splicing would be associated with these behaviors during an extended withdrawal period of 2 months. Motivation was measured using an operant orofacial assay at non-aversive temperatures (37°C) while anxiety and stress were measured by examining this behavior at aversive temperatures (46°C). Lower C1 and C2 expression levels were observed in the AMY in a subset of the population of withdrawn rats even after 2 months of morphine withdrawal. These subsets were associated with a hypersensitivity to adverse conditions which may reflect long-term alterations in the withdrawn population.

MRI features of the complete histopathological response of locally advanced rectal cancer to neoadjuvant chemoradiotherapy

AIM

To describe the post-chemoradiotherapy magnetic resonance imaging (MRI) features of locally advanced rectal carcinoma (LARC) in which there has been a complete histopathological response to neoadjuvant chemoradiotherapy (CRT).

MATERIALS AND METHODS

This retrospective cohort study was performed between January 2005 and November 2009 at a regional cancer centre. Consecutive patients with LARC and a histopathological complete response to long-course CRT were identified. Pre- and post-treatment MRI images were reviewed using a proforma for predefined features and response criteria. ymrT0 was defined as the absence of residual abnormality on MRI.

RESULTS

Twenty patients were included in the study. Seven (35%) ypT0 tumours were ymrT0. All 13 ypT0 tumours not achieving ymrT0 appearances had a good radiological response, with at least 65% tumour reduction. The appearances were heterogeneous: in 11/13 patients the tumour was replaced by a region of at least 50% low signal on MRI, with 8/13 having ≥80% low signal, and 3/13 with 100% low signal.

CONCLUSION

MRI may be useful in identifying a complete histopathological response. However, the MRI appearances of ypT0 tumours are heterogeneous and conventional MRI complete response criteria will not detect the majority of patients with a complete histopathological response.

Abstract P2-09-23: Investigating VAV3 Expression as a Novel Biomarker and Indicator of Chemosensitivity in Basal-Like Breast Cancer

Background: Basal-like breast (BLB) cancer accounts for ∼15% of all breast cancers diagnosed. Patients with BLB cancer are typically younger, present with higher tumor grade and despite recent advances in therapy, still have a poor outcome. BLB cancers are the most proliferative breast tumor sub-type, are commonly triple-negative (ER-, PgR-, HER2/neu-), and often harbor mutations in TP53 and BRCA1. The biological drivers of disease progression in this tumor subtype remains poorly understood. Recently, VAV3, a guanine nucleotide exchange factor and a member of the of the Rho/Rac/Cdc42 GTPase superfamily, has been reported as overexpressed and oncogenic in ER+ breast cancer cells. Our preliminary studies using publicly available microarray data indicates a consistent lack of VAV3 in BLB cancer, particularly those patients with shorter survival time following chemotherapy. We therefore hypothesize that VAV3 is a novel biomarker of BLB cancer and potential predictor of chemosensitivity in this subtype.

Materials and Methods: Gene expression microarray technology, qRTPCR and western blotting was used to investigate relative expression of VAV3 in a panel of breast cancer cell lines and tumors. Array Comparative Genomic Hybridization and Fluorescence in Situ Hybridization were used to evaluate VAV3 gene copy number. BLB cancer cell lines stably overexpressing VAV3 were developed to evaluate the role of VAV3 in sensitivity to chemotherapy.

Results: Unsupervised hierarchical clustering revealed low VAV3 expression in BLB tumors compared to all other intrinsic subtypes. Consistently lower VAV3 mRNA and protein expression were observed in BLB cancer cell lines compared to luminal epithelial cell lines, consistent with our in silico observations. We confirmed that low VAV3 expression in the BLB cancer cell lines is not due to gene copy number loss. Ectopic expression of VAV3 in MDA-MB-231 BLB cancer cells significantly enhanced their sensitivity to cisplatin.

Discussion: A consistent lack of VAV3 gene expression is evident in BLB tumors, however the mechanism underlying this loss is yet to be elucidated. Our findings support a hypothesis that low VAV3 expression is a potential diagnostic biomarker of BLB cancer, and that VAV3 expression may be a predictor of response to chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-23.

Evaluation of a general practice based hepatitis C virus screening intervention

BACKGROUND

In 2003 an estimated 37,500 of Scotland's population was chronically infected with HCV; 44% were undiagnosed former injecting drug users (IDU)--a priority group for antiviral therapy.

AIM

To evaluate a hepatitis C virus (HCV) screening intervention.

DESIGN

Outcome measures among two similar General Practice populations in an area of high HCV and drug use prevalence, one of which was exposed to an HCV screening intervention, were compared.

METHODS

Thirty to fifty four year old attendees of the intervention practice were opportunistically offered testing and counselling, where clinically appropriate, (November 2003-April 2004).

OUTCOMES

HCV test uptake, case detection, referral and treatment administration rates.

RESULTS

Of 584 eligible attendees, 421 (72%) were offered and 117 (28%) accepted testing in the intervention practice; no testing was undertaken in the comparison practice. Prevalences of HCV antibody were 13% (15/117), 75% (3/4) and 91% (10/11) among all tested persons, current IDUs and former IDUs respectively. For 4/15 (27%) evidence of binge drinking following the receipt of their positive result, was available. Of the 11 referred to specialist care because they were HCV RNA positive, nine attended at least one appointment. Two received treatment: one had achieved a sustained viral response as of February 2008.

CONCLUSION

While non targeted HCV screening in the general practice setting can detect infected former IDU, the low diagnostic yield among non IDUs limited the effectiveness of the intervention. A more targeted approach for identifying former IDUs is recommended. Additionally, the low uptake of treatment among chronically infected persons four years after diagnosis demonstrates the difficulties in clinically managing such individuals. Strategies, including support for those with a history of problem alcohol use, to improve treatment uptake are required.

CT Scanning in Stroke Patients: Meeting the Challenge in the Remote and Rural District General Hospital

Introduction

National audit data allow crude comparison between centres and indicate that most Scottish hospitals fail to meet current guidelines for CT scanning of the brain in stroke patients. This study identifies some of the reasons for delay in performing CT scans in a largely rural population.

Methods

This audit study assesses the delays from onset of symptoms, time of admission and request received to CT scan in stroke patients for three different in-patient groups as well as those managed in the community.

Results

The reasons for delay in CT scanning varied between different patient groups but for one group of in-patients, changes in booking procedure and introduction of a second CT scanner increased the proportion scanned within 48 hours of request from 65% to 96%.

Discussion

Further developments including the introduction of Saturday and Sunday routine CT scanning, radiologist reporting from home and additional CT scanners placed in remote hospitals may be expected to improve these figures further. Target times of three hours from onset of symptoms to scan to allow thrombolysis may however be impossible to meet for all stroke patients in rural areas.

An evidence-based review for the management of cystic pancreatic lesions

The incidental finding of pancreatic cysts is becoming more common because of the increased use of cross-sectional imaging. As a result, the perspective from historical series of symptomatic patients is not always applicable to the current cohort of patients with cystic lesions in their pancreas. In this review, the characteristic radiological features that aid diagnosis are highlighted, and the complementary role of different imaging methods and the appropriate use of tissue sampling are identified. Based on the literature regarding the diagnostic role of imaging in characterizing cystic pancreatic lesions, it is possible to recommend a practical imaging algorithm for the diagnosis of cystic pancreatic lesions.

Renal subcapsular pseudocyst: findings on MRI

Pancreatic pseudocysts are common complications of pancreatitis. They may occur in unusual places as a result of spread along the path of least resistance. Penetration of Gerota's fascia and spread into the renal subcapsular space are uncommon. Their appearance on magnetic resonance imaging has not been previously documented. Given the increased use of magnetic resonance cholangiopancreatography for the investigation of patients with pancreatitis, the recognition that a complicated renal cyst in this clinical context could represent a benign condition is important.

Gene profiling study of G3139- and Bcl-2-targeting siRNAs identifies a unique G3139 molecular signature

G3139 is a phosphorothioate oligodeoxyribonucleotide that is targeted to the initiation codon region of the Bcl-2 mRNA, which downregulates Bcl-2 protein and mRNA expression via an antisense mechanism. In previous work, we have demonstrated that the phenotype observed in several prostate and melanoma cell lines after treatment with G3139 appears to be Bcl-2 independent. In contrast, downregulation of Bcl-2 expression by a small interfering RNA (siRNA) produced little or no phenotype change. In the present work, we performed an Agilent oligonucleotide microarray assay on mRNA isolated from PC3 prostate cancer cells that were treated with two different oligonucleotide gene-silencing reagents. G3139 and a Bcl-2-targeting siRNA both downregulate Bcl-2 expression, but via different mechanisms. A side-by-side comparative analysis showed that the expression profile generated by these molecules differs substantially. The study revealed upregulation of the expression of stress-inducible genes in PC3 cells at 1 and 3 days after a 5-h transfection with G3139 complexed with Lipofectamine 2000. In contrast, only a very diminished stress response was seen 1 and 3 days after a 24-h transfection of siRNA/Lipofectamine 2000 complexes. These results highlight the profound differences in off-target effects in cells treated with the phosphorothioate oligonucleotide G3139 and with an siRNA targeted to the same gene, and provide further evidence that the mechanism of action of G3139 is not related to Bcl-2 silencing.

Multidetector computed tomography urography (MDCTU) for diagnosing urothelial malignancy

Multidetector computed tomography (MDCT) is well established for the detection of stones and renal masses, but more recently MDCT urography (MDCTU) is becoming widely used for examination of the entire urinary tract aimed specifically for diagnosing urothelial lesions. Evidence is rapidly accumulating to support the use of MDCTU in this manner. Familiarity with the MDCTU signs of urothelial malignancy is a prerequisite for optimum radiological practice. This article provides a review of the appearances of transitional cell cancer in the upper urinary tract and bladder.

Sigmoid colonic perforation and pelvic abscess complicating biliary stent migration

Endoscopically placed biliary stents are a well-established procedure for the treatment of benign and malignant causes of obstructive jaundice in patients unfit for definitive surgical intervention. Stent migration has been described, though in most instances the stent will pass or remain in the bowel lumen for extended periods of time. Only a few cases of clinically significant complications of stent migration have been reported. This is the first case report of a pelvic abscess complicating stenting for choledocholithiasis. As the numbers of stenting procedures continue to increase it may be anticipated that the numbers of complications will similarly increase.

A survival analysis of clinically significant change in outpatient psychotherapy

The number of sessions required to produce meaningful change has not been assessed adequately, in spite of its relevance to current clinical practice. Seventy-five clients attending outpatient therapy at a university-affiliated clinic were tracked on a weekly basis using the Outcome Questionnaire (Lambert et al., 1996) in order to determine the number of sessions required to attain clinically significant change (CS). Survival analysis indicated that the median time required to attain CS was 11 sessions. When current data were combined with those from an earlier investigation (Kadera, Lambert, and Andrews, 1996), it was found that clients with higher levels of distress took 8 more sessions to reach a 50% CS recovery level than clients entering with lower levels of distress. At a six-month follow-up, CS gains appeared to have been maintained. Other indices of change also were examined (reliable change, average change per session). The implications of these results for allocating mental-health benefits, such as the number of sessions provided through insurance, are discussed.

Engaging distortions: are we idealizing marriage?

The present study was an investigation of the premarital status of engagement in terms of relationship satisfaction and marital expectations using the Evaluation and Nurturing Relationship Issues, Communication and Happiness (ENRICH) Marital Satisfaction Scale (EMS) and its two subscales of Idealistic Distortion (ID) and Marital Satisfaction (MS) (D. G. Fournier, D. H. Olson, & J. M. Druckman, 1983). There were 104 students (23 men and 81 women), of which 15 were married, 19 were engaged, and 70 had extended dating relationships. On average, participants had been in the relationship for 3.8 years, and the mean age was 22 years. Results demonstrated that individuals engaged to be married had significantly higher idealistic distortion scores (M = 86.89) than did either married individuals (M = 56.67) or those in extended dating relationships (M = 61.19). Finally, a negative relation was found between length of relationships and marital satisfaction subscores. Results are discussed in light of factors contributing to such idealized thinking.

Status of nutrition labeling, health claims, and nutrient content claims for processed foods: 1997 Food Label and Package Survey

The Food and Drug Administration (FDA) conducts studies of food labels as part of its ongoing monitoring of the nutritional status of the US population. In 1994 FDA nutrition labeling rules were implemented and in 1997 the Food Label and Package Survey characterized various aspects of the labeling of processed, packaged foods, including nutrition labeling, health claims, and nutrient content claims. For the survey, FDA selected a multistage, representative sample of food products from the SCAN-TRACK food sales database (AC Nielsen Co, Schaumburg, Ill). FDA identified 58 product groups and selected those product classes from the database that accounted for 80% of sales in each group. From each product class, FDA selected the 3 top-selling product brands and randomly selected follower brands. Based on label information from a final sample of 1,267 food products, FDA determined the percentage of products sold that bear Nutrition Facts labels, health claims, and nutrient content claims. The purpose of this article was to present FDA findings regarding the status of food labels 3 years after implementation of the nutrition labeling rules. Nutrition-labeled products accounted for an estimated 96.5% of the annual sales of processed, packaged foods. An additional 3.4% of products sold were exempt from labeling regulations. Nutrient content claims and health claims appeared on an estimated 39% and 4%, respectively, of the products sold. Dietitians and other health care professionals can use this survey information to identify food types with specific label information and to assist the US consumer in making more varied and healthful food choices in the marketplace.

Concerns about allegations of child sexual abuse against teachers and the teaching environment

OBJECTIVE

The major objective was to determine teachers' awareness of the potential for child abuse allegations against themselves and the effects on the teaching environment.

METHOD

Of 3,000 questionnaires sent out to a random sample of New York state teachers, 515 were returned. The responding teachers were similar to New York state teachers in terms of gender, age, and racial/ethnic distribution.

RESULTS

A large percent of the respondents (56%) were aware of false allegations made against a teacher in their school district. About a third (36.5%) expressed concern that a child abuse allegation could be made against them. In response to a vignette, forty-two (42%) advised a new teacher against being alone in a room with a student; 62% advised against casual touching; 70% advised against hugging or putting an arm around a student. Males more than female teachers, especially those teaching upper grades, advised against such contact. The more teachers expressed concern about abuse allegations against themselves, the more teachers advised against contact.

CONCLUSIONS

Fear of abuse allegations are salient for teachers. Fears may cause teachers to limit contact with students with potentially adverse consequences for students and the teaching environment.

Mutagenesis and comparative sequence analysis of a base triple joining the two domains of group I ribozymes

Tertiary interactions are important in the higher-order folding of catalytic RNAs. Recently, a base triple, joining the two major domains of the catalytic core, was determined in group I introns from the cyanobacterium Anabaena PCC7120 and the eukaryote Tetrahymena thermophila. This base triple involves the fifth base pair of P4 and the fifth base of the single-stranded region J8/7. We made base pair and single-nucleotide substitutions in the fifth base pair of P4, a G-C in the wild-type Anabaena intron, and tested them for self-splicing activity. The results suggest a hydrogen bonding model in which only the C of the base pair interacts directly with the fifth base of J8/7. Comparative sequence analysis was used to determine the different combinations of base triples that occur in approximately 450 natural group I introns identified to date. About 94% of the base triples analyzed are compatible with the proposed hydrogen bonding model. Disrupting this base triple in the Tetrahymena intron resulted in the disappearance of splicing intermediates (intron 3' exon and 5' exon), even though the first step of splicing was not affected. Restoration of the base triple by a compensatory mutation reverted the intermediates to wild-type levels. These results suggest that disruption of the base triple increases the rate of the second step of splicing or of a conformational change preceding the second step. Repositioning of the base triple to form a new set of interactions may be required for the second step of splicing.

Does angiotensin play a role in human fetal erythropoiesis?

Angiotensin affects the growth of many cell types and there have been suggestions that it could influence cells which respond to erythropoietin. During first trimester, human fetal haematopoietic cells are exquisitely responsive to erythropoietin and we have assessed the potential for angiotensin to also influence the growth of these cell types in a standard culture system. The data obtained from these studies indicate that angiotensin does not influence fetal haematopoiesis over a range of concentrations.

In utero haematopoietic stem cell transplantation: current perspectives and future potential

In utero transplantation (IUT) of haematopoietic cells is a new therapeutic option for families with increased risk of having a child with an inherited disorder. Immunological naiveté and the rapidly expanding haematopoietic system in the first trimester human fetus, make therapeutic intervention by IUT a real possibility for those disorders which can be diagnosed early in gestation. Fewer cells are required than in postnatal BMT and therapy can be offered before the pathological sequelae of a disorder become manifested. However, only a few cases of IUT have been performed in humans and it is imperative that consensus is reached quickly on issues such as cell numbers/cell types so that the benefits of this approach to treatment can be realised. This review presents the current status of IUT, the cases thus far recorded and offers a prospective view of developments in this rapidly expanding area.

Gestational age and cell viability determine the effect of frozen storage on human fetal hematopoietic progenitor cell preparations

We have assessed hematopoietic progenitor cell preparations (including CD34-positive stem cells) obtained from human fetal liver at 6-17 weeks of gestational age for total cell numbers, viability and the ability to tolerate (frozen) storage. Hematopoietic cell preparations obtained from the 16-to 17-week gestational age range had the highest total cell count and the greatest proportion of CD34-positive stem cells. However, these preparations were insufficiently robust to withstand the freeze/thaw protocol required. Cells obtained from the 13- to 15-week gestational age range showed optimal post-thaw viability and it is suggested that these cell preparations are the most applicable for in utero transplantation.

Factor structure of the Private Self-Consciousness Scale

Several issues concerning the factors of the Private Self-Consciousness Scale (PRSC) of Fenigstein et al. (1975) are examined, including possible artifactuality and appropriate conceptualization. Findings confirm the existence of the 2 factors reported in previous research (Burnkrant & Page, 1984; Lennox, Welch, Wolfe, Zimmerman, & Dixon, 1987; Mittal & Balasubramanian, 1987; Piliavin & Charng, 1988) and suggest that these factors are substantive, not artifactual, in nature. One factor was found to be associated with mild levels of psychopathology, whereas the other was not. In addition to providing a clearer conception of the nature of these factors, our results may help to resolve apparently contradictory findings in the PRSC literature. Implications for research on self-focused attention are also discussed.

The effect of folate on the methotrexate/indomethacin interaction in a murine cancer cell line

1. The effect of folate on the interaction between methotrexate (a folate analogue) and indomethacin has been examined in murine NC carcinoma cells. 2. Conditioning of NC cells to a physiological (20 nM) folate concentration after culture in a high folate concentration increased the response to methotrexate. The sensitivity of these conditioned cells to methotrexate related inversely to the folate concentration. 3. At 20 nM and 2 microM folate, indomethacin 1 micrograms ml-1 potentiated the cytotoxicity of methotrexate 4 and 8 ng ml-1 (both P < 0.03). 4. When NC cells were incubated with [3H]-methotrexate at 20 nM and 2 microM folate, there was a trend for increased tritium accumulation with indomethacin 0.36 micrograms ml-1 (1 microM; P < 0.01). 5. We conclude that the folate concentration can affect the sensitivity of NC cells to methotrexate, although the degree of potentiation of cytotoxicity by indomethacin remains similar.

Long-term storage of human fetal haematopoietic progenitor cells and their subsequent reconstitution. Implications for in utero transplantation

Haematopoietic progenitor cells were isolated from human fetal liver, obtained between 6 and 15 weeks gestation. After preparation of a single cell suspension, the cells were stored using a stepwise freezing protocol; taking the cells from room temperature through -70 degrees C to liquid nitrogen. Viability (trypan blue exclusion), morphology (Leishman stain), identification of cell type (flow cytometry) and growth characteristics in semi-solid culture medium were assessed using the fresh cell suspension. We were able to confirm that the predominant cells in human fetal liver up to about 15 weeks gestation are those of the erythroid lineage. It was established that viability in excess of 75% was required to ensure adequate growth in culture after frozen storage and it was deemed important to ensure morphological integrity of the cell preparations. The colonies formed in culture were observed to be producing haemoglobin between 7 and 9 days after initial seeding. We have determined that cells can be stored in liquid nitrogen for up to 2 years without loss of (1) viability, (2) morphological features and (3) ability to form colonies and produce haemoglobin in culture. These findings offer encouragement for the implementation of a cell bank to support an in utero transplantation programme.

Interaction between methotrexate and indomethacin on a human normal haemopoietic cell line

1. The interaction between methotrexate and indomethacin has been examined, at a physiological folate concentration (20 nM), on a human normal lymphoblast-like cell line (RPMI 1788) in vitro. 2. Indomethacin (1 microgram ml-1) increased the reduction of lymphoblast growth caused by methotrexate (10-80 ng ml-1). 3. Indomethacin (0.1 and 1 microgram ml-1) potentiated the cytotoxicity of methotrexate (20 and 40 ng ml-1) after 4 days in culture. 4. Indomethacin (0.4 micrograms ml-1) reduced the accumulation of tritium in lymphoblasts incubated with [3H]-methotrexate after 30 min; therefore initial drug accumulation was not responsible for the potentiation seen after 4 days. 5. If indomethacin increases the killing of human cancer cells by methotrexate in vivo, with a smaller potentiation on lymphoblasts, this combination may be beneficial in treating human malignancy.

Potential application of LASER/microbe bioassay technology for determining water-soluble vitamins in foods

A microbiological technique was developed for quantitating niacin by determining microbial growth rates in response to the amount of vitamin available. Unlike the current official AOAC method, the new procedure for niacin measured the growth rates during the early exponential growth phase rather than during the stationary phase. Lactobacillus plantarum was used to determine niacin to a lower limit of 100 pg/mL. The assay time was approximately 6 h, compared with 16-24 h for the current AOAC method. The extent of microbial growth was determined by differential light scattering of a LASER beam. Multiple photodetectors were integrated with a computer system to collect and analyze the data. The use of differential light scattering to determine 8 water-soluble vitamins under stationary phase conditions demonstrated the potential application of the new technology for microorganisms and foods.

Turbidimetric microbiological assay results calculated by a BASIC computer program

A BASIC computer program was used to calculate the results of microbiological vitamin assays. The program, which incorporates the official AOAC guidelines for microbiological methods, reduces the uncertainty inherent in manual curve plotting and interpolation and minimizes the human error of repetitive calculations. Because the BASIC programming language is well suited for use on self-contained personal computers, it can be easily adapted by small laboratories.

Advances in vertebral artery surgery at the skull base

Between July 1975 and May 1985, 219 procedures were performed on the vertebral system; two were intracranial, 118 were at the skull base and 99 were at the neck base. Of the 108 patients operated on at the skull base, procedures were multiple in five and bilateral in two. Bypass to the vertebral artery between the transverse process of C1 and C2 was performed 91 times. The blood supply for the bypass was the common carotid (70), the external carotid (9), the internal carotid (9), the subclavian (3), and the occipital artery (3). Decompression was performed in three patients, segmental resection in seven, and ligation in two. The primary objective was to increase the flow capacity of the vertebral artery. This flow to the Circle of Willis supplies the forebrain and the hindbrain if the internal carotid artery is obstructed and the posterior communicating artery is patent, or it may supply only the hindbrain when no communication exists. The pathologic processes include atherosclerosis, thrombosis, dissection, compression, and vasospasm. The male:female ratio is 2:3. Long-term mortality is 19% for the male and 4.6% for the female. Hindbrain symptoms in the male predates cardiac symptoms by 2 to 4 years. Operative mortality and stroke rate is less than 3% combined. Long-term graft patency is 87%. Vertebral artery surgery at the skull base produces results superior to those following proximal segment reconstruction when measured by dynamic computerized tomographic scanning, neurofunctional testing, and symptom relief. Success following reconstruction depends on careful patient selection and surgical expertise. The techniques of reconstruction are well established and results have been durable for over a decade.

Cerebral hemodynamics evaluation

The cerebral hemodynamic evaluation is the embodiment of a system approach to the hemodynamic factors that affect brain blood flow. The stresses employed are those encountered in everyday living. The instruments are simple and the method is basic. The importance of the cardiovascular response to the upright position and of brain perfusion to head motion deserves close attention in the clinical setting. The CHE complements the angiogram, the CT scan, and CT-rBBC studies by addressing the system and arterial hemodynamic factors affecting brain circulation. The CT-rBBC studies have given greater validity and direction to noninvasive and electrophysiologic testing because the ultimate concern is brain perfusion and function and not the angiogram. This combination of techniques has defined the role of the dynamic arterial obstruction and the vertebral artery in the hemodynamics of the brain. The cerebral hemodynamic evaluation is an integral part of the physiologic approach to the diagnosis and treatment of brain ischemia.

Pacemakers, cardiac mapping and EEG in the community hospital: a concise review of background and basic technical considerations

The heart is a pump. The objective of cardiac pacing is to improve the cardiac output. The most popular method of cardiac pacing (RV) is not physiologic and results in reduced stroke output when compared to that of normal sinus or atrial paced rhythm. Recognition of pacemaker induced low output states and pacemaker aggravated neurological symptoms has quickened interest in physiologic atrial pacing. The increased complexity of atrial pacing has been discouraging in the past, but technical advances in electrode and pacemaker design are promising. Selection of the optimal pacing site appears critical and requires the determination of the focal electrical potential and stimulating threshold before electrodes are positioned. With minimal expense, the EEG can be adapted for this type of cardiac mapping in the community hospital.

Impairment of a motor skill in children with spina bifida cystica and hydrocephalus: an exploratory study

Twenty 7-10 year old children with spina bifida cystica and hydrocephalus and 20 normals matched for age, sex and IQ were compared on a 12-trial target task, first used by Connolly, Brown & Bassett (1968). Analysis of the results, in which particular attention was paid to statistical method and to ways of analysing individual differences, showed a significant impairment in dotting speed in the spina bifida group, although both groups improved with practice. In a second experiment immediately following the first, visual monitoring of this task was restricted. The spina bifida children were initially more affected than the controls but able to recover. The findings are discussed in relation to neurological abnormalities in the spina bifida group.