Advanced frailty assessment tool predicts successful awake craniotomy in a 92-year-old patient: A case report

Background:

The awake craniotomy (AC) procedure allows for safe and maximal resection of brain tumors from highly eloquent regions. However, geriatric patients are often viewed as poor candidates for AC due to age and medical comorbidities. Frailty assessments gauge physiological reserve for surgery and are valuable tools for preoperative decision-making. Here, we present a novel case illustrating how frailty scoring enabled an elderly but otherwise healthy female to undergo successful AC for tumor resection.

Case Description:

A 92-year-old right-handed female with history of hypertension and basal cell skin cancer presented with a 1-month history of progressive aphasia and was found to have a ring-enhancing left frontoparietal mass abutting the rolandic cortex concerning for malignant neoplasm. Frailty scoring with the recalibrated risk analysis index (RAI-C) tool revealed a score of 30 (of 81) indicating low surgical risk. The patient and family were counseled appropriately that, despite advanced chronological age, a low frailty score predicts favorable surgical outcomes. The patient underwent left-sided AC for resection of tumor and experienced immediate improvement of speech intraoperatively. After surgery, the patient was neurologically intact and had an unremarkable postoperative course with significant improvements from preoperatively baseline at follow-up.

Conclusion:

To the best of our knowledge, this case represents the oldest patient to undergo successful AC for brain tumor resection. Nonfrail patients over 90 years of age with the proper indications may tolerate cranial surgery. Frailty scoring is a powerful tool for preoperative risk assessment in the geriatric neurosurgery population.

Exploring the utility of the Threshold of Toxicological Concern (TTC) as a screening approach for complex substances

The Threshold of Toxicological Concern (TTC) has been applied to assess chemical safety for use, particularly in the food safety area. Although the TTC was developed for application to an individual chemical structure, more recently this concept has been suggested for the assessment of combined exposures to multiple chemicals. This study evaluated the potential for applying the TTC to a specific type of co-exposure, that of a complex substance of variable composition which contains multiple constituents, following the World Health Organization/International Programme on Chemical Safety framework for risk assessment of combined exposure to multiple chemicals. The results indicated that the TTC threshold was lower (i.e., more conservative) than regulatory thresholds derived for the same substance or even its most toxic constituent, providing assurance that the TTC could meet the requirements for a conservative screening process. This case study indicates that the TTC concept can be a useful tool to screen for potential risks from complex substances, with the consideration of additional aspects such as variability in chemical constituents and their relative proportions within the substance.

Infectious titres of human papillomaviruses (HPVs) in patient lesions, methodological considerations in evaluating HPV infectivity and implications for the efficacy of high-level disinfectants

BACKGROUND

Recent publications from a single research group have suggested that aldehyde-based high-level disinfectants (HLDs), such as ortho-phthalaldehyde (OPA), are not effective at inactivating HPVs and that therefore, patients may be at risk of HPV infection from medical devices. These results could have significant public health consequences and therefore necessitated evaluation of their reproducibility and clinical relevance.

METHODS

We developed methods and used standardised controls to: (1) quantify the infectious levels of clinically-sourced HPVs from patient lesions and compare them to laboratory-derived HPVs, (2) evaluate experimental factors that should be controlled to ensure consistent and reproducible infectivity measurements of different HPV genotypes, and (3) determine the efficacy of select HLDs.

FINDINGS

A novel focus forming unit (FFU) infectivity assay demonstrated that exfoliates from patient anogenital lesions and respiratory papillomas yielded infectious HPV burdens up to 2.7 × 103 FFU; therefore, using 2.2 × 102 to 1.0 × 104 FFU of laboratory-derived HPVs in disinfection assays provides a relevant range for clinical exposures. RNase and neutralising antibody sensitivities were used to ensure valid infectivity measures of tissue-derived and recombinant HPV preparations. HPV infectivity was demonstrated over a dynamic range of 4-5 log10; and disinfection with OPA and hypochlorite was achieved over 3 to >4 log10 with multiple genotypes of tissue-derived and recombinant HPV isolates.

INTERPRETATION

This work, along with a companion publication from an independent lab in this issue, address a major public health question by showing that HPVs are susceptible to HLDs.

FUNDING

Advanced Sterilization Products; US NIH (R01CA207368, U19AI084081, P30CA118100).

Behind the Mask: An Exploratory Assessment of Female Surgeons' Experiences of Gender Bias

Though overt sexism is decreasing, women now experience subtle, often unconscious, gender bias as microaggressions. The authors sought to explore the prevalence and impact of the sexist microaggressions female surgeons experience, using a sequential exploratory mixed methods approach (January 2018-April 2018), to identify opportunities for education and prevention. First, all resident, fellow, and attending female surgeons at the University of New Mexico Health Sciences Center (UNM HSC) were invited to participate in focus groups conducted by experienced moderators using a semistructured interview guide based on the 7 Sexist Microaggressions Experiences and Stress Scale (Sexist MESS) domains. Qualitative analysis was performed using line-by-line manual coding to identify themes aligned with the Sexist MESS domains as well as other gender bias experiences of female surgeons. Next, a survey was sent to all resident, fellow, and attending female surgeons at the UNM HSC, which included the Sexist MESS questionnaire and questions related to surgeon-specific experiences of gender bias that the authors developed based on major thematic categories from the focus groups.Four focus groups of 23 female surgeons were conducted, revealing 4 themes: exclusion, increased effort, adaptation, and resilience to workplace slights. The survey response rate was 64% (65/101 surgeons). Across Sexist MESS domains, the frequency and severity of microaggressions was higher for trainees than attendings. The variables of non-White race/ethnicity, having children under 18, and fellowship training generally did not demonstrate statistical significance. This exploratory study adds to the growing body of evidence that gender bias in surgery continues and frequently manifests as microaggressions. Trainees reported the highest rates and severity of microaggressions and bias experiences. Further research should investigate how to address microaggressions, the experiences of male surgeons, the perspectives of medical students and groups who were reported as often perpetuating gender bias, and the efficacy of possible interventions.

Matrix metalloproteinases cleave membrane-bound PD-L1 on CD90+ (myo-)fibroblasts in Crohn's disease and regulate Th1/Th17 cell responses

Increased T helper (Th)1/Th17 immune responses are a hallmark of Crohn's disease (CD) immunopathogenesis. CD90+ (myo-)fibroblasts (MFs) are abundant cells in the normal (N) intestinal mucosa contributing to mucosal tolerance via suppression of Th1 cell activity through cell surface membrane-bound PD-L1 (mPD-L1). CD-MFs have a decreased level of mPD-L1. Consequently, mPD-L1-mediated suppression of Th1 cells by CD-MFs is decreased, yet the mechanism responsible for the reduction in mPDL-1 is unknown. Increased expression of matrix metalloproteinases (MMPs) has been reported in CD. Herein we observed that when compared to N- and ulcerative colitis (UC)-MFs, CD-MFs increase in LPS-inducible levels of MMP-7 and -9 with a significant increase in both basal and inducible MMP-10. A similar pattern of MMP expression was observed in the CD-inflamed mucosa. Treatment of N-MFs with a combination of recombinant human MMP-7, -9 and -10 significantly decreased mPD-L1. In contrast, inhibition of MMP activity with MMP inhibitors or anti-MMP-10 neutralizing antibodies restores mPD-L1 on CD-MFs. CD-MFs demonstrated reduced capacity to suppress Th1 and Th17 responses from activated CD4+ T cells. By contrast, supplementation of the CD-MF:T-cell co-cultures with MMP inhibitors or anti-MMP neutralizing antibodies restored the CD-MF-mediated suppression. Our data suggest that (i) increased MMP-10 expression by CD-MFs and concomitant cleavage of PD-L1 from the surface of CD-MFs are likely to be one of the factors contributing to the decrease of mPD-L1-mediated suppression of Th1/Th17 cells in CD; and (ii) MMPs are likely to have a significant role in the intestinal mucosal immune responses.

An analysis of 3,954 cases to determine surgical wound classification accuracy: Does your institution need a monday morning quarterback?

INTRODUCTION

Surgical site infections reporting has financial implications for institutions under Centers for Medicare and Medicaid Services (CMS) Pay-for-Performance programs. Surgical Wound Classification (SWC) is an important factor in performing risk adjustment and affects the accuracy of the Standardized Infection Ratio (SIR). This in turn leads to more accurate inter-hospital ratings and reimbursement. This study aims to measure (1) services and procedures associated with the highest rates of misclassification and (2) whether temporal factors influenced misclassification.

METHODS

Accuracy of SWC was assessed by comparing the wound classification documented by the Operating Room (OR) nurse at the time of the operation to the actual SWC determined from in-depth chart review using Centers for Disease Control and Prevention (CDC) wound classification algorithm by a trained reviewer. Cases were reviewed once operative reports were available.

RESULTS

Review of 3954 cases yielded an overall discordance rate of 22.15% (N = 876), with most cases being under-classified. Services with the highest rates of discordance include cardiothoracic (38.46%) and general surgery (37.86%), followed by general oncology (29.46%), OB-GYN (28.93%), urology (27.27%), and plastic surgery (27.14%). Procedures with the highest discordance rates are laparoscopic appendectomy (66.67%), cholecystectomy (52.90%), exploratory laparotomy (49.21%), and split-thickness skin graft (36.84%). Discordance rates were significantly higher (p = 0.0001) during weekends compared to weekdays, while operations starting after-hours during the week did not show a significant difference from daytime hours.

CONCLUSION

At a level 1 trauma academic medical center, certain procedures were found to be misclassified in regards to SWC more often than other types of cases. The timing of the case, such that they occurred on the weekends also contributed to higher discordance rates between original and corrected wound classifications. Recognizing cases, services, and temporal factors frequently associated with misclassification of wound class can help allocate limited resources to maximize improvement of this important metric.

Gender Bias Experiences of Female Surgical Trainees

OBJECTIVE

Medical schools now average approximately 50% female students, yet a disproportionate number of women continue to choose nonsurgical over surgical specialties. Once in training, studies indicate that pervasive gender stereotypes, sexism and harassment negatively affect female surgeons. The aim of this study is to describe female surgeons' experiences with gender bias and microaggressions in the workplace during residency and fellowship training, and understand if differences exist in the experiences of trainees in male-dominant vs female-dominant surgical specialties.

DESIGN

A mixed methods approach was used to explore the experiences of female surgical trainees. Participants were recruited from all surgical disciplines at an academic center. Initially, focus groups were used to explore themes that trainees face related to gender bias. A trained moderator conducted all focus groups, which were audio recorded and transcribed. Qualitative analysis of de-identified transcripts was performed to identify emerging themes. We then created an online survey using the validated 44-question Sexist Microaggression Experiences and Stress Scale to assess frequency and psychologic impact of these events with additional questions developed from the focus groups. The survey was sent to all female residents and fellows at one academic institution.

SETTING

University of New Mexico Hospital, a tertiary care academic medical center.

PARTICIPANTS

Fifteen female surgical trainees participated in focus groups. Thirty-three female surgical trainees participated in the online survey.

RESULTS

Two focus groups including 15 female trainees were conducted, revealing 4 themes: Exclusion, Adaptation, Increased effort, and Development of Resilience Strategies. All participants had experienced gender bias or discrimination during medical school or surgical training. The quantitative survey had a 66% response rate (33/50 female trainees). Significant differences were found in the experience of female trainees in male-dominant vs female-dominant specialties, with those in male-dominant fields often reporting more frequent, severe, and stressful microaggression experiences. When describing how gender bias would affect their future in medicine, trainees in male-dominant specialties were more likely to report that due to gender bias, they "may leave medicine/retire early" (33% vs 6%, p = 0.040) and that they "would not recommend my profession to trainees or family members" (40% vs 6%, p = 0.015)."

CONCLUSIONS

Female surgical trainees continue to experience gender bias. A culture of sexism leads to physical and social adaptations to fit into the role of surgeon. Participants expressed significant effort to sustain this level of adaptation, leading to fatigue and creation of resilience mechanisms. The environment in which a trainee operates (male-dominant vs female-dominant) significantly impacts their experience. Those experiencing more bias were less likely to recommend their specialty and reported plans to leave medicine earlier. Culture change across institutions and system-level interventions are necessary to create meaningful and sustainable change that improves the experience of female surgical trainees.

Operating room staff and surgeon documentation curriculum improves wound classification accuracy

BACKGROUND

Misclassification of wounds in the operating room (OR) can adversely affect surgical site infection (SSI) reporting and reimbursement. This study aimed to measure the effects of a curriculum on documentation of surgical wound classification (SWC) for operating room staff and surgeons.

METHODS

Accuracy of SWC was determined by comparing SWC documented by OR staff during the original operation to SWC determined by in-depth chart review. Patients 18 years or older undergoing inpatient surgical procedures were included. Two plan-do-act-study (PDSA) cycles were implemented over the course of 9 months. A total of 747 charts were reviewed. Accuracy of SWC documentation was retrospectively assessed across 248 randomly selected surgeries during a 5-week period prior to interventions and compared to 244 cases and 255 cases of post-intervention data from PDSA1 and PDSA2, respectively. Changes in SWC accuracy were assessed pre- and post-intervention using the kappa coefficient. A p-value for change in agreement was computed by comparing pre- and post-intervention kappa.

RESULTS

Inaccurate documentation of surgical wound class decreased significantly following curriculum implementation (kappa improved from 0.553 to 0.739 and 0.757; p = 0.001). Classification accuracy improved across all wound classes; however, class III and IV wounds were more frequently misclassified than class I and II wounds, both before and after the intervention.

CONCLUSION

Implementation of a multidisciplinary documentation curriculum resulted in a significant decrease in SWC documentation error. Improved accuracy of SWC reporting may facilitate a better assessment of SSI risk in a complex patient population.

Expression of Programmed Death-Ligand 1 by Human Colonic CD90+ Stromal Cells Differs Between Ulcerative Colitis and Crohn's Disease and Determines Their Capacity to Suppress Th1 Cells

Background and Aims

The role of programmed cell death protein 1 (PD-1) and its ligands in the dysregulation of T helper immune responses observed in the inflammatory bowel disease (IBD) is unclear. Recently, a novel concept emerged that CD90⁺ colonic (myo)fibroblasts (CMFs), also known as stromal cells, act as immunosuppressors, and are among the key regulators of acute and chronic inflammation. The objective of this study was to determine if the level of the PD-1 ligands is changed in the IBD inflamed colonic mucosa and to test the hypothesis that changes in IBD-CMF-mediated PD-1 ligand-linked immunosuppression is a mechanism promoting the dysregulation of Th1 cell responses.

Methods

Tissues and cells derived from Crohn's disease (CD), ulcerative colitis (UC), and healthy individuals (N) were studied in situ, ex vivo, and in culture.

Results

A significant increase in programmed death-ligand 1 (PD-L1) was observed in the inflamed UC colonic mucosa when compared to the non-inflamed matched tissue samples, CD, and healthy controls. UC-CMFs were among the major populations in the colonic mucosa contributing to the enhanced PD-L1 expression. In contrast, PD-L1 expression was decreased in CD-CMFs. When compared to CD-CMFs and N-CMFs, UC-CMFs demonstrated stronger suppression of IL-2, Th1 transcriptional factor Tbet, and IFN-γ expression by CD3/CD28-activated CD4⁺ T cells, and this process was PD-L1 dependent. Similar observations were made when differentiated Th1 cells were cocultured with UC-CMFs. In contrast, CD-CMFs showed reduced capacity to suppress Th1 cell activity and addition of recombinant PD-L1 Fc to CD-CMF:T cell cocultures partially restored the suppression of the Th1 type responses.

Conclusion

We present evidence showing that increased PD-L1 expression suppresses Th1 cell activity in UC. In contrast, loss of PD-L1 expression observed in CD contributes to the persistence of the Th1 inflammatory milieu in CD. Our data suggest that dysregulation of the Th1 responses in the inflamed colonic mucosa of IBD patients is promoted by the alterations in PD-L1 expression in the mucosal mesenchymal stromal cell compartment.

Using Qualitative and Quantitative Assessment to Develop a Patient Safety Curriculum for Surgical Residents

OBJECTIVE

The objective is to use qualitative and quantitative analysis to develop a patient safety curriculum for surgical residents.

DESIGN

A prospective study of surgical residents using both quantitative and qualitative methods to craft a patient safety curriculum. Both a survey and focus groups were held before and 4 months after delivery of the patient safety curriculum.

SETTING

The University of New Mexico Hospital, a tertiary academic medical center.

PARTICIPANTS

General surgery residents, postgraduate years 1 to 5 RESULTS: Qualitative and quantitative analysis revealed areas that required attention and thus helped to mold the curriculum. Qualitative analysis after delivery of the curriculum showed positive changes in attitudes and normative beliefs toward patient safety. Specifically, attitudes and approach to quality improvement and teamwork showed improvement. Survey analysis did not show any significant change in resident perception of the environment during the time frame of this study.

CONCLUSIONS

Using qualitative analysis to uncover attitudinal barriers to a safe patient environment can help to enhance the relevance and content of a patient safety curriculum for general surgery residents.

Competency champions in the clinical competency committee: a successful strategy to implement milestone evaluations and competency coaching

OBJECTIVES

To create a clinical competency committee (CCC) that (1) centers on the competency-based milestones, (2) is simple to implement, (3) creates competency expertise, and (4) guides remediation and coaching of residents who are not progressing in milestone performance evaluations.

DESIGN

We created a CCC that meets monthly and at each meeting reviews a resident class for milestone performance, a competency (by a faculty competency champion), a resident rotation service, and any other resident or issue of concern.

SETTING

University surgical residency program.

PARTICIPANTS

The CCC members include the program director, associate program directors, director of surgical curriculum, competency champions, departmental chair, 2 at-large faculty members, and the administrative chief residents.

RESULTS

Seven residents were placed on remediation (later renamed as coaching) during the academic year after falling behind on milestone progression in one or more competencies. An additional 4 residents voluntarily placed themselves on remediation for medical knowledge after receiving in-training examination scores that the residents (not the CCC membership) considered substandard. All but 2 of the remediated/coached residents successfully completed all area milestone performance but some chose to stay on the medical knowledge competency strategy.

CONCLUSIONS

Monthly meetings of the CCC make milestone evaluation less burdensome. In addition, the expectations of the residents are clearer and more tangible. "Competency champions" who are familiar with the milestones allow effective coaching strategies and documentation of clear performance improvements in competencies for successful completion of residency training. Residents who do not reach appropriate milestone performance can then be placed in remediation for more formal performance evaluation. The function of our CCC has also allowed us opportunity to evaluate the required rotations to ensure that they offer experiences that help residents achieve competency performance necessary to be safe and effective surgeons upon completion of training.

Stapled revision of complete colorectal anastomotic obstruction

Colonic and rectal anastomotic strictures occur with an incidence ranging from 3% to 30%. Several factors, such as defunctionalization, anastomotic leak, ischemia, radiation, and neoplasms, have been implicated in their pathogenesis. Management of large bowel strictures is generally based on their cause, location, and appearance. Various methods have been described, including endoscopic techniques (eg, balloon dilatation and/or stents) and operative revision. Postoperative rectal strictures usually respond well to direct dilatation, without the need for endoscopic balloons. If surgical revision is necessary, morbidity can be significant, as in any reoperative procedure. We hereby present a novel surgical method of revision for a complete anastomotic obstruction, which proved effective and avoided extensive operative dissection, mobilization, and re-resection.

Differential alterations in tachykinin NK2 receptors in isolated colonic circular smooth muscle in inflammatory bowel disease and idiopathic chronic constipation

Inflammatory bowel disease (IBD) and idiopathic chronic constipation (ICC) are intestinal disorders which disrupt normal colonic motility. Enteric tachykinins are well-recognised to play a role in the motor control of the gut, and increased colonic levels of substance P are seen in IBD, whereas decreased levels have been reported in ICC. In this investigation, we have characterised the tachykinin receptor population of normal human colonic circular smooth muscle and examined any changes that occur in IBD and ICC. The selective tachykinin NK2 receptor agonist, [beta-Ala8]neurokinin A(4-10), caused concentration-dependent contractions in healthy tissues; neither NK1 receptor-selective nor NK3 receptor-selective agonists were contractile. In diseased preparations also, only [beta-Ala8]neurokinin A(4-10) caused contractions with EC50 values similar to health. The maximum contractile responses (Emax), however, were significantly decreased in both forms of IBD but significantly increased in ICC. The muscarinic acetylcholine receptor agonist, carbachol, also caused contractions in diseased tissues, but EC50 and Emax values were not significantly different from health. The differential changes in contractility found in IBD and ICC are specific to NK2 receptors, and may reflect the altered levels of substance P or other tachykinins found in these intestinal disorders.

Breeding of retroviruses by DNA shuffling for improved stability and processing yields

Manufacturing of retroviral vectors for gene therapy is complicated by the sensitivity of these viruses to stress forces during purification and concentration. To isolate viruses that are resistant to these manufacturing processes, we performed breeding of six ecotropic murine leukemia virus (MLV) strains by DNA shuffling. The envelope regions were shuffled to generate a recombinant library of 5 x 106 replication-competent retroviruses. This library was subjected to the concentration process three consecutive times, with amplification of the surviving viruses after each cycle. Several viral clones with greatly improved stabilities were isolated, with the best clone exhibiting no loss in titer under conditions that reduced the titers of the parental viruses by 30- to 100-fold. The envelopes of these resistant viruses differed in DNA and protein sequence, and all were complex chimeras derived from multiple parents. These studies demonstrate the utility of DNA shuffling in breeding viral strains with improved characteristics for gene therapy.

Rates of small intestinal mucosal protein synthesis in human jejunum and ileum

We investigated possible differences in the rates of mucosal protein synthesis between the proximal and distal regions of the small intestine. We took advantage of access to the gut mucosa available in otherwise healthy patients with ileostomy in whom the terminal ileum was histologically normal. All subjects received primed, continuous intravenous infusions of L-[1-(13)C]leucine after an overnight fast. After 4 h of tracer infusion, jejunal biopsies were obtained using a Crosby-Kugler capsule introduced orally; ileal biopsies were obtained via endoscopy via the ileostomy. Protein synthesis was calculated from protein labeling relative to intracellular leucine enrichment obtained by appropriate mass spectrometric measurements. Rates of jejunal and ileal mucosal protein synthesis were significantly different (P < 0.001) at 2.14 +/- 0.2 and 1.2 +/- 0.2 %/h (means +/- SD). These are lower than rates in normal healthy duodenum (2.53 +/- 0.25 %/h), suggesting a gradation of rates of synthesis along the bowel. Together with other data, these results suggest that mucosae of the bowel contribute not more than 10% to whole body protein turnover.

Toxicology of n-pentane (CAS no. 109-66-0)

n-Pentane (CAS no. 109-6-0) is a hydrocarbon solvent with an estimated production volume of 50000 metric tons in Europe. The present work was carried out to strengthen the toxicological information available for regulatory decision-making, particularly product classification, occupational exposure limits and risk assessment. The work described in this report was sponsored either by the Pentane Special Interest Group under the auspices of the Hydrocarbon Solvent Producers Association of CEFIC (European Chemical Industry Council) or by Exxon Chemical Europe. The following results were obtained: n-pentane was not acutely toxic by oral or inhalation routes, it was not a skin or eye irritant and did not induce skin sensitization. It did not exhibit cumulative toxicity at levels up to 20000 mg m(-3), which is approximately one-half of the lower explosive limit and the highest level considered safe to test. It did not induce developmental toxicity and was not mutagenic. From this and other existing information, it is concluded that n-pentane does not require classification for potential toxic hazards (as defined by Annex VI of the EU Dangerous Substance Directive, 1993), although the physical properties indicate that it would be appropriate to warn for the potential for aspiration. Further, there is no reason to reduce the current occupational exposure recommendations. Finally, although there are some safety issues relating to the flammability of n-pentane, the absence of any demonstrable toxicity at high treatment levels indicates that the risk of adverse health effects is minimal for all segments of the population.

Chromosomal characterization of MRC-5 cell banks utilizing G-banding technique

We have performed chromosomal monitoring on 18 MRC-5 cell banks using the G-banding technique. A higher frequency of structural abnormalities and hyperdiploidy was detected with respect to the numerical values that were established with conventional staining techniques and reported in the 1979 Ad Hoc Committee guideline on karyology controls of human cell substrates. These numerical criteria have been adopted by international regulatory agencies to release human diploid cell banks (WI-38 and MRC-5) for vaccine manufacture. In the process of characterizing these 18 cell banks, a 7;12 translocation clone was detected in 7 cell banks at a frequency ranging from 0.2 to 5.6%. The presence of the t(7;12) appears to be biphasic. At low population doubling levels (PDLs) (< 30), t(7;12) is rarely observed. However, the incidence of t(7;12) increases and plateaus between PDL 40-50. A decrease in frequency is observed at higher PDLs. Before senescence of the cell bank, t(7;12) is not observed. Investigation of the growth characteristics of MRC-5 cells revealed that cell banks containing the translocation senesced at similar PDLs compared to MRC-5 cells with no detectable 7;12 translocation. In addition, MRC-5 cell banks containing the t(7;12) have successfully completed tumorigenicity testing in a nude mouse model. We conclude that MRC-5 cells obtained from either National Institute for Biological Standards and Control (NIBSC) or American Type Culture Collection (ATCC) contain a 7;12 translocation at a low frequency. This abnormality does not provide MRC-5 cell bank mass cultures with a growth advantage nor is it tumorigenic in nude mice. Furthermore, the presence of this clone and employment of the G-banding technique may be responsible for the increased observation of structural abnormalities in our laboratories. In view of this information, the cytogenetic criteria that were established in 1979 with conventional staining techniques are not appropriate for human diploid cell banks that are examined with more sensitive methodology. Since it has been recognized that MRC-5 and WI-38 cells are safe biological substrates, we recommend that MRC-5 and WI-38 cell banks should only be identified by using an appropriate identity test and should not require any chromosomal analysis before being used as a cell substrate for the manufacture of live virus vaccines.

A prospective trial of endoscopic sclerotherapy v oesophageal transection and gastric devascularisation in the long term management of bleeding oesophageal varices

In a prospective three centre study oesophageal transection and gastric devascularisation have been compared with endoscopic sclerotherapy in the long term management of bleeding oesophageal varices. Cirrhotic patients (Child's A or B grade) with documented bleeding oesophageal varices were treated initially with emergency sclerotherapy, and after five days stability, were allocated to one of the two treatment regimes. The endoscopic sclerotherapy group underwent regular sclerotherapy until variceal obliteration while those undergoing surgery were not endoscoped unless bleeding recurred, when they were treated by sclerotherapy if appropriate. Ninety two patients were eligible for analysis (68% alcoholic cirrhosis; mean age 50.1 years) and follow up was achieved for a mean of 52.5 months (range 17-83). Mortality in the first three months was greater in the oesophageal transection and gastric devascularisation group (20% v 1%) but by two years the survival curves were the same and thereafter there was no difference in mortality. Rebleeding occurred in 13/41 (31%) patients, undergoing oesophageal transection and gastric devascularisation. The costs incurred during the first year of oesophageal transection and gastric devascularisation treatment were significantly greater than with endoscopic sclerotherapy (4369 pounds v 1067 pounds, p < 0.0001) and the high rate of rebleeding in the surgical group meant that no cost savings occurred in subsequent years. It is concluded that oesophageal transection and gastric devascularisation confers no benefit over endoscopic sclerotherapy in terms of long term survival and that it is not cost effective as judged by the current health care costs in the United Kingdom.

Influence of prior events on cognitive judgments in amnesia

Amnesic patients and control Ss read the names of famous and nonfamous persons. Subsequently, both groups were more likely to designate a name as famous if it had been encountered previously. The facilitatory effect of prior presentation was similar for amnesic patients and control Ss and similar for famous and nonfamous names. For amnesic patients, the effect occurred despite severely impaired recognition memory for the names. In a 2nd experiment, recombining the first and last names that had been presented together did not diminish the facilitatory effect of prior presentation, which indicates that the effect does not depend on forming an association between first and last names. The results show that nondeclarative (implicit) memory can support the acquisition of information that is specific (e.g., names of persons) and that has no preexisting representation (e.g., nonfamous names).

Influence of prior events on cognitive judgments in amnesia

Amnesic patients and control Ss read the names of famous and nonfamous persons. Subsequently, both groups were more likely to designate a name as famous if it had been encountered previously. The facilitatory effect of prior presentation was similar for amnesic patients and control Ss and similar for famous and nonfamous names. For amnesic patients, the effect occurred despite severely impaired recognition memory for the names. In a 2nd experiment, recombining the first and last names that had been presented together did not diminish the facilitatory effect of prior presentation, which indicates that the effect does not depend on forming an association between first and last names. The results show that nondeclarative (implicit) memory can support the acquisition of information that is specific (e.g., names of persons) and that has no preexisting representation (e.g., nonfamous names).

Impaired anal sensation and early diabetic faecal incontinence

Faecal incontinence develops in up to 20% of diabetic patients. To try to determine the relative contributions of sensory and motor neuropathy in this troublesome complication, anorectal function was examined in 10 male diabetic patients with early faecal incontinence (mucus leakage or faecal staining without the need to wear a pad), 10 asymptomatic male diabetic patients, and 10 normal control subjects. Motor function was tested using anal manometry to determine the resting and maximum squeeze pressure, and the functional anal canal length. No significant differences were found between the groups. Sensory function was tested by measuring the mucosal sensitivity to electrical stimulation, and the response to inflation of a balloon in the rectum. In the mid-anal canal position the symptomatic patients had a significantly higher sensory threshold at 6.6 +/- 2.8 mA compared with 3.0 +/- 1.2 mA in the normal control subjects (p less than 0.002), and in the high anal zone symptomatic patients had a significantly elevated sensory threshold at 9.1 +/- 2.0 mA compared with 4.6 +/- 1.6 mA in asymptomatic patients and 3.6 +/- 1.3 mA in the normal control subjects (both p less than 0.001). There were no significant differences in the first sensation of fullness, maximum tolerated volume or percentage fall from resting pressure between the groups on inflation of the balloon. Elevation of the sensory threshold in the upper anal canal is an early abnormality in the development of diabetic faecal incontinence.

A study of octreotide in oesophageal varices

A comparison of octreotide infusion (25 micrograms/h) and placebo in 16 stable cirrhotic patients revealed a 30% reduction in transhepatic venous gradient between 0 and 60 min in the octreotide group without an effect on systemic haemodynamics. In a separate trial, 40 patients with active variceal bleeding were randomized to octreotide infusion (25 micrograms/h for 48 h) or oesophageal tamponade. The 2 treatments gave comparable control of variceal bleeding. Tolerance of treatment was significantly better in the octreotide group. In summary, octreotide infusion is simple to administer, has few side effects, and may be of use in the immediate control of oesophageal bleeding.

A simple and efficient non-organic procedure for the isolation of genomic DNA from blood

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Muscle creatine content in rats given repeated large doses of nicotinamide: effects of dietary methionine, choline, carnitine, and other supplements

Rats fed a 12% casein diet without added choline were chronically injected with pharmacologic doses of nicotinamide (NAM) for 18 to 28 d in three experiments. In addition to fatty livers and lower weight gains, the creatine content of heart and skeletal muscle was lower in NAM-treated than in control saline-injected rats. Dietary supplements of methionine prevented these alterations, and choline, depending on the level of supplementation, also had some similar effects. No consistent responses could be demonstrated by supplements of carnitine, histidine or folic acid plus vitamin B-12.

Does antibiotic prophylaxis at the time of catheter insertion reduce the incidence of catheter-related sepsis in intravenous nutrition?

Fifty-five patients referred for intravenous nutrition were randomised to receive either vancomycin (500 mg) or no vancomycin immediately before catheter insertion. Catheter insertion and management were standard in all patients. The mean duration of intravenous feeding was similar in both groups (vancomycin: 17.7 +/- 9.6 days; no vancomycin: 16.5 +/- 8.8 days). Overall, the bacteriologically confirmed catheter-related sepsis was 25% and was not reduced by the prophylactic administration of vancomycin.