Optimizing the Handling of Invasive Fungal Sinusitis Surgical Specimens

Introduction/Objective

Invasive fungal sinusitis (IFS) is an aggressive disease characterized by invasion of fungal hyphae into tissue/neurovascular bundles. This project assessed the handling of IFS specimens and implemented protocols to improve turnaround time (TAT).

Methods

A retrospective review of cases accessioned with a clinical concern for IFS from 2014-2019 was performed. TAT for each step in the specimen processing was recorded. A flowchart was created using stakeholder interviews and a revised protocol was developed after assessing critical needs. Assessment of interventions was performed following implementation of the new protocol. The protocol will be evaluated by prospective direct case-by-case feedback and after a 6-month interval (projected August/2020). At 6-months, goals are a 24 hours median time between frozen section and sign-out and elimination of outliers (greater than 2 working days).

Results

We identified 53 specimens from 32 patients in the pre-intervention period (36 cases positive for IFS). Median time from frozen section to final sign-out was 28 (5-312) hours. Four areas for improvements were identified:

(1) triaging specimens to different protocols according to arrival time, (2) optimized triaging for available histology processors, (3) standardized GMS ordering, and (4) standardized case delivery/communication with sign-out staff. Interventions include: protocol for processing specimens based on time of day, new histology protocols to expedite GMS performance, an email group for rapid communication with staff pathologists and histology, and a worksheet/checklist to track each case. After implementation of the protocol, 8 cases from 7 patients were received. Median time from frozen section to final sign-out was reduced to 20 (2 – 50) hours.

Conclusion

The protocol for handling IFS specimens became live on 2/1/2020. It has reduced TAT of suspected IFS cases, from a median of 28 hours to 20 hours. The longest interval to sign-out went from312 hours to 50 hours.

P87 Spinal fractures incurred by a fall from standing height

Objectives

Falls from standing are an important cause of vertebral fractures, particularly in the elderly. They are associated with significant morbidity and long-term mortality. The aim of this study was to determine the treatment and outcomes, in a single centre, of managing spinal fractures due to falls from standing height.

Design

Retrospective case note review of patients with a fracture sustained due to a fall from standing (2011–2016 inclusive).

Subjects

229 patients with average age 76.6±14.5 years; 134 (58.5%) female.

Methods

Patients were identified from the Trauma Audit and Research Network database. Case notes were reviewed for demographics, treatment details and outcome at 6 months post-admission.

Results

1408 patients were admitted with spinal fractures of which 229 (16.3%) sustained a fall from standing height. Two hundred and eighty-three fractures were identified in the 229 patients, which were distributed in the cervical (n=140), thoracic (n=65) and lumbar (n=78) spine. The average ISS score was 9.7±5.4. Twenty-three (10.0%) patients had either incomplete or complete spinal cord injury. Fifty-six (24.5%) patients underwent surgical intervention. Forty-three patients (18.7%) died within 6 months and increasing age and Charlson co-morbidity score were associated with higher mortality.

Conclusions

Falls from standing comprise a large portion of the spinal service emergency workload. They are associated with a high 6 month mortality similar to other fragility fractures experienced by the elderly.

Creation of Secondary AV Fistulas from Failed Hemodialysis Grafts: The Role of Routine Vein Mapping

Pre-existing forearm grafts lead to dilatation of upper arm veins of the ipsilateral arm that greatly facilitates the creation of secondary arteriovenous fistulas (AVF). In this retrospective review of 18 patients, the routine and periodical revision of failed grafts were discontinued. Vein mapping by physical examination or Duplex studies was performed prior to graft failure and a secondary AVF was created when the graft failed. Using this management strategy, an AVF creation success rate of 95% was achieved despite high incidence of co-morbidity factors within the patient population. This success rate demonstrates the value of vein selection by vascular mapping prior to graft failure and early vascular access planning in the successful creation of secondary AVF.

Successful AV Fistula Creation does not Lead to Higher Catheter Use: The Experience by the Northwest Renal Network 16 Vascular access Quality Improvement Program. Four Years follow-up

Background

In 2002, the Center for Medicare and Medicaid Services (CMS) required all 18 Renal Networks to participate in a Vascular Access Quality Improvement Program (QIP). The Northwest Renal Network (NWRN 16) chose to increase arteriovenous fistula (AVF) use. NWRN 16 hypothesized that strategies which targeted the improvement of AVF rate and the reduction of catheter use were the same. In December 2001, 44.2% of hemodialysis (HD) patients in the NWRN 16 received HD using an AVF which met the Dialysis Outcome Quality Initiative (K/DOQI) 40% AVF guideline for prevalent patients. However, 43% of HD facilities (2869 patients) had less than 40% of AVF and higher HD catheter rates than the average Network catheter rates (25.0 vs. 20.3%). To address the needs of underperforming facilities, NWRN 16 provided education and tools for their vascular access decision makers to promote AVF creation and catheter reduction.

Methods

In 2002, NWRN 16 sponsored four regional workshops targeted at nephrologists, vascular surgeons, HD nurses, and interventional radiologists.

Results

Percentage of AVFs in use in invited facilities increased from 31.3% pre-intervention to 56.2% at 4 yrs: 78% increase (99% confidence interval: 77.8% to 81.5%). Percentage of catheters increased from 25% to 25.8%: 3.2% change over 4 yrs (99% confidence interval: 2.5% to 4%).

Conclusion

The success of Network 16's AVF interventions demonstrates the effectiveness of Network education promoting multidisciplinary teamwork, and innovative strategies to increase dramatically AVF use without substantial increase in catheter use.

Successful Multidisciplinary Interventions for Arterio-Venous Fistula Creation by the Pacific Northwest Renal Network 16 Vascular access Quality Improvement Program

Background

In December 2001, 44.2% of hemodialysis (HD) patients in the Northwest Renal Network (NWRN 16) received dialysis using an arteriovenous fistula (AVF). Substantial differences were noted in percentages of patients with AVF, ranging from 5% to 90% of the facility population, suggesting wide variation in physician practice patterns within the Network. To address the needs of facilities having <40% AVF, NWRN 16 provided education and tools for their vascular access decision-makers to promote AVF creation.

Methods

In 2002, the Network sponsored 4 regional workshops targeted to nephrologists, vascular surgeons, dialysis nurses, and interventional radiologists.

Results

46 facilities (43% of all Network facilities) had <40% AVF in use in December, 2001, dialyzing 2940 patients (Invited Units). Percent AVF in use in all the Invited Facilities increased from 31.3% pre-intervention to 39.8% at 1 year (p<0.001 vs pre) to 56.2% at four years: 79.8% increase in the prevalent AVF rate over a four-year period (95% confidence interval: 77.8% to 81.7%).

Conclusion

Low prevalent AVF rates in many NWRN 16 facilities may have resulted from differences in physician practice patterns. The success of Network 16 AVF Intervention demonstrates the effectiveness of Network education promoting multidisciplinary teamwork, innovative strategies to increase AVF rates among dialysis patients.

Potential for improving fiber digestion in the rumen of cattle (Bos taurus) through microbial inoculation from bison (Bison bison): In situ fiber degradation

The objective of this experiment was to determine if partial replacement of cattle rumen contents with those from bison would increase in situ ruminal fiber degradation of various forages. The second objective was to examine individual variation among cattle in their ability to degrade forage and their responses to inoculation. In situ degradation of barley straw, canola straw, alfalfa hay, and timothy hay was measured in 16 ruminally cannulated heifers fed a barley straw-based diet before and after inoculation with combined rumen contents from 32 bison (performed twice, 14 d apart). Each feed was incubated in the rumen of each heifer for 0, 4, 8, 12, 24, 48, 96, and 120 h, and the degradation parameters were determined as washout fraction (), potentially degradable fraction (), rate of digestion of fraction (), and total potentially degradable fraction (). The of barley straw decreased ( = 0.04) after inoculation, whereas fraction of NDF increased ( = 0.03) and fraction of NDF and ADF decreased ( ≤ 0.02) by inoculation. In contrast, of alfalfa hay NDF and ADF decreased ( = 0.002) after inoculation, but fraction of NDF and ADF ( ≤ 0.02) increased. There were no major effects ( > 0.06) of inoculation on the fiber degradation of timothy hay or canola straw. The differential response between barley straw and alfalfa hay may have occurred because the cattle were previously adapted to a barley straw diet, whereas the bison were fed barley silage and oats. Some animals consistently ranked higher or lower for or across at least 3 of the 4 feeds incubated, but the rankings changed after inoculation. In conclusion, inoculation of cattle with bison rumen contents failed to improve degradation of fiber from barley straw, canola straw, or timothy hay in cattle well adapted to a barley straw diet, although there were small improvements in the extent of degradation of fiber from alfalfa hay. Cattle varied both in their ability to degrade various forages and in their responses to inoculation with bison rumen contents.

Surface Sampling and the Detection of Contamination

Cross-contamination is an increasingly important risk factor in food safety. Cleaning and disinfection regimens are essential components in its prevention but need to be validated, monitored, and verified. This in turn requires the implementation of protocols for surface sampling and the assessment of residual contamination. Visual assessment although widely used, in isolation, is ineffective but can be useful as part of an integrated approach. Microbial and nonmicrobial methods of sampling and testing are compared. Nonmicrobial assessment methods, especially ATP, are effective at monitoring residual surface soil. Traditional specific, and nonspecific, microbial methods indicate residual microbial contamination but not surface soil. Recent advances in molecular microbial methods and bioluminogenic tests are discussed. There is no single ideal surface test method and how, when, and where to sample are discussed within the framework of suggested guidelines, an integrated approach, and the use of trend analysis.

Development of an oncolytic herpes simplex virus using a tumor-specific HIF-responsive promoter

We exploited the differential activation of hypoxia-inducible factor (HIF)-dependent gene expression in tumors versus normal tissue for the design of a targeted oncolytic Herpes simplex virus type-1 (HSV-1). A gene that is essential for viral replication, ICP4, was placed under the regulation of a HIF-responsive promoter and then introduced into the thymidine kinase locus (U_L23) of HSV d120 which contains partial deletions in the two endogenous ICP4 genes. Recombinant HIF-HSV were isolated and their derivation from d120 was verified by expression of a truncated, nonfunctional form of ICP4 protein. Disruption of the U_L23 locus was confirmed by loss of thymidine kinase expression and resistance to acyclovir. Unexpectedly, HIF-HSV expressed ICP4 and induced tumor cell lysis at similar levels under normoxia and hypoxia. The lack of HIF-dependent ICP4 transgene expression by HIF-HSV was due to two factors that have not previously been reported- reversion of the ICP4 gene region to its wild-type configuration and increased HIF-transcriptional activity under normoxia when cells were infected with any strain of HSV-1. The findings that an oncolytic HSV-1 is genetically unstable and can activate a tumor-related promoter in a non-specific manner have important implications for any proposed use of this virus in cancer therapy.

A modified ATP benchmark for evaluating the cleaning of some hospital environmental surfaces

Hospital cleaning continues to attract patient, media and political attention. In the UK it is still primarily assessed via visual inspection, which can be misleading. Calls have therefore been made for a more objective approach to assessing surface cleanliness. To improve the management of hospital cleaning the use of adenosine triphosphate (ATP) in combination with microbiological analysis has been proposed, with a general ATP benchmark value of 500 relative light units (RLU) for one combination of test and equipment. In this study, the same test combination was used to assess cleaning effectiveness in a 1300-bed teaching hospital after routine and modified cleaning protocols. Based upon the ATP results a revised stricter pass/fail benchmark of 250 RLU is proposed for the range of surfaces used in this study. This was routinely achieved using modified best practice cleaning procedures which also gave reduced surface counts with, for example, aerobic colony counts reduced from >100 to <2.5 cfu/cm(2), and counts of Staphylococcus aureus reduced from up to 2.5 to <1 cfu/cm(2) (95% of the time). Benchmarking is linked to incremental quality improvements and both the original suggestion of 500 RLU and the revised figure of 250 RLU can be used by hospitals as part of this process. They can also be used in the assessment of novel cleaning methods, such as steam cleaning and microfibre cloths, which have potential use in the National Health Service.

Problems associated with traditional hygiene swabbing: the need for in-house standardization

AIMS

To investigate factors influencing the recovery of micro-organisms from surfaces using traditional swabbing techniques.

METHODS AND RESULTS

Stainless steel squares were inoculated with known levels (approx. 2.7x10(2)-2.7x10(4)) of either Escherichia coli or Staphylococcus aureus and sampled using different swab/solution combinations. Overlaying the coupons with agar allowed colonies remaining on the surface to be enumerated. Conventional cultivation was used to determine the ease with which the bacteria were released from the swabs and the viability of the organisms within the solutions over a 24-h period. Minimal bacterial growth occurred when the samples were stored at 4 degrees C. At room temperature, whilst the presence of nutrients significantly increased bacterial numbers over time, the addition of Tween 80 to nutrient depleted environments significantly reduced the viability of Staph. aureus. The percentage of bacteria released from directly inoculated swabs was significantly higher than that recovered from surface swabs, highlighting the importance of effectively removing bacterial contaminants from a surface. Increasing the level of mechanical energy generated during swabbing increased the number of bacteria removed from a wet surface. However, it is hypothesized that cellular damage, perhaps caused by the swabbing action itself, may have reduced recoverability from a dry surface. Nonetheless, an increased ability to effectively remove bacteria from a surface did not necessarily correlate with higher bacterial recovery, implying that an equally important factor in terms of swabbing efficiency is the ability of a swab to effectively release bacteria into a diluent.

CONCLUSIONS

Both swab and wetting solution can influence the number of bacteria recovered. Under the experimental conditions described here, the use of swabs coated with a brush-textured nylon flock in combination with a non-growth-enhancing wetting solution appeared the best system to use when sampling a wet surface. However, this combination may not always be ideal and proper consideration must be given to how the sample is to be taken, transported and, if necessary, stored prior to analysis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Careful selection of swabbing materials can increase the sensitivity of traditional microbiological analysis. However, any improvements made are likely to be insignificant in relation to the overall poor performance of the swabbing technique.

An oncolytic mutant of herpes simplex virus type-1 in which replication is governed by a promoter/enhancer of human papillomavirus type-16

Although herpes simplex virus type-1 (HSV-1) can be used as an oncolytic virus it has the undesirable side effect of neurotoxicity. To create a virus with improved specificity for oral cancer we used a fragment of human papillomavirus type-16, which is frequently found in oral and cervical cancers, but not elsewhere. The upstream regulatory region, URR16, was shown to have a high level of transcriptional activity in three of four oral cancer cell lines but low activity in three cell lines derived from brain cancers. URR16 was therefore placed in HSV-1, replacing the promoter of the essential gene ICP4, and the resulting virus was named HSPV-1. When cells were infected with HSPV-1, ICP4 was expressed at levels that were not associated with the level of activity of URR16. The virus replicated in each type of cell to a final titer that showed a correlation with the level of expression of ICP4, but with no correlation to either the tumor of origin or the presence of HPV sequences in the cells. To find if some function of HSV-1 was affecting the activity of URR16, oral cancer cells were transfected with a URR-reporter construct and were then infected with virus. This induced transcription, which was attributed to immediate-early viral genes other than ICP4. A promoter/enhancer from a papillomavirus therefore has the potential to regulate the functions of an oncolytic strain of HSV-1, and is affected by functions of both the host cell and of HSV-1 itself.

Creation of secondary AV fistulas from failed hemodialysis grafts: the role of routine vein mapping

Pre-existing forearm grafts lead to dilatation of upper arm veins of the ipsilateral arm that greatly facilitates the creation of secondary arteriovenous fistulas (AVF). In this retrospective review of 18 patients, the routine and periodical revision of failed grafts were discontinued. Vein mapping by physical examination or Duplex studies was performed prior to graft failure and a secondary AVF was created when the graft failed. Using this management strategy, an AVF creation success rate of 95% was achieved despite high incidence of co-morbidity factors within the patient population. This success rate demonstrates the value of vein selection by vascular mapping prior to graft failure and early vascular access planning in the successful creation of secondary AVF.

Successful multidisciplinary interventions for arterio-venous fistula creation by the Pacific Northwest Renal Network 16 vascular access quality improvement program

BACKGROUND

In December 2001, 44.2% of hemodialysis (HD) patients in the Northwest Renal Network (NWRN 16) received dialysis using an arteriovenous fistula (AVF). Substantial differences were noted in percentages of patients with AVF, ranging from 5% to 90% of the facility population, suggesting wide variation in physician practice patterns within the Network. To address the needs of facilities having < 40% AVF, NWRN 16 provided education and tools for their vascular access decision-makers to promote AVF creation.

METHODS

In 2002, the Network sponsored 4 regional workshops targeted to nephrologists, vascular surgeons, dialysis nurses, and interventional radiologists.

RESULTS

46 facilities (43% of all Network facilities) had <40% AVF in use in December, 2001, dialyzing 2940 patients (Invited Units). Percent AVF in use in all the Invited Facilities increased from 31.3% pre-intervention to 39.8% at 1 year (p<0.001 vs pre) to 56.2% at four years: 79.8% increase in the prevalent AVF rate over a four-year period (95% confidence interval: 77.8% to 81.7%).

CONCLUSION

Low prevalent AVF rates in many NWRN 16 facilities may have resulted from differences in physician practice patterns. The success of Network 16 AVF Intervention demonstrates the effectiveness of Network education promoting multidisciplinary teamwork, innovative strategies to increase AVF rates among dialysis patients.

A laboratory evaluation of the decontamination properties of microfibre cloths

Standards of cleanliness in health care continue to attract attention. Effective cleaning requires the input of energy, and microfibre cloths may help in the physical removal of soil. The ability of these cloths to remove organic soil (measured by ATP) and bacteria was compared with paper towel and a conventional cloth in controlled wet and dry conditions. When used wet on a dry surface, the cleaning ability of six different microfibre cloths was variable, and in most cases, not significantly better than paper towel or a conventional cloth. One type of microfibre cloth did perform significantly better than the others and paper towel in reducing both organic soil and microbial load. When used dry on a dry surface, there was no significant difference between the cloths, and none of the cloths reduced microbial and organic bioburden effectively. The ability of the cloths to recontaminate the surface was also tested, and some of the microfibre cloths transferred significantly less organic debris and micro-organisms back to the surface than other cloths. Different makes of microfibre cloths have different characteristics, and the name 'microfibre' should not imply superior cleaning efficacy.

Brain volume measurements in patients with human T-cell lymphotropic virus-1–associated tropical spastic paraparesis

Human T-cell lymphotropic virus (HTLV)-1 is associated with a chronic progressive neurologic disease known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) that affects 0.2% to 3% of HTLV-1-infected people. The authors aimed at exploring, in vivo, whether brain volume reduction occurs in patients with HAM/TSP through the use of magnetic resonance imaging (MRI). T1 pre/postcontrast spin echo-weighted images (WIs) and T2WIs of the brain were obtained in 19 HAM/TSP patients and 14 age-and sex-matched healthy volunteers. Both patients and healthy individuals were imaged at a 1.5-Tesla magnet by employing a conventional head coil. Focal T1 and T2 abnormalities were calculated and two measurements of brain parenchyma fraction (BPF) were obtained by using SIENAx (Structural Image Evaluation,using Normalisation, of Atrophy; University of Oxford, Oxford, UK) and MIPAV (Medical Image Processing, Analysis, and Visualization; National Institutes of Health, Bethesda, USA) from T1WIs. No significant differences in BPF were found between patients and healthy subjects when using either SIENAx or MIPAV. Analysis of individual patients detected that BPF was lower by 1 standard deviation (SD) relative to patients' average BPF in one patient. The authors conclude that reductions in BPF do not occur frequently in patients with HAM/TSP. However, the authors believe that one individual case of significant brain atrophy raises the question as to whether atrophy selectively targets the spinal cord of HAM/TSP patients or may involve the brain as well. A larger patient population analyzing regional brain volume changes could be helpful in determining whether brain atrophy is a marker of disease in patients with HAM/TSP.

The microbiological quality of washing-up water and the environment in domestic and commercial kitchens

AIMS

To determine the microbiological quality of washing-up water and the environment in domestic and commercial kitchens.

METHODS AND RESULTS

Chicken meals were prepared by people without food safety training in their own kitchen (n = 52) or by trained staff in a commercial kitchen (n = 10). Study participants then washed-up, cleaned the kitchen and completed a food hygiene questionnaire. The temperature and microbiological quality of the washing-up water, and the presence of pathogens in dishcloths, tea towels and other kitchen samples was determined. Of the raw chickens used in meal preparation, 96 and 13% were naturally contaminated with Campylobacter or Salmonella spp., respectively. In domestic kitchens, two of 45 sponges, dishcloths or scourers and one of 32 hand- or tea towels were contaminated with Campylobacter after washing-up and cleaning but none of the tap or sink swabs yielded pathogens. The mean washing-up water temperature in the domestic kitchens was 40.7 degrees C, whereas in the commercial kitchen it was 44.7 degrees C (P = 0.04). Study participants who used hotter water (>/=40 degrees C) had lower levels of bacteria in their washing-up water. The aerobic plate counts of the washing-up water samples in domestic homes were usually between 105 and 106 CFU ml-1 but those associated with the commercial kitchen were consistently lower (P = 0.01). Despite this, Campylobacter was detected in one of 10 washing-up water samples from the commercial kitchen but in none of the samples from domestic kitchens.

CONCLUSIONS

Pathogenic microorganisms can be recovered relatively frequently from the kitchen environment.

SIGNIFICANCE AND IMPACT OF STUDY

By identifying factors that affect the number of microorganisms in washing-up water and the kitchen environment, evidence-based recommendations on implementing domestic food hygiene can be made.

Combined MR imaging and numerical simulation of flow in realistic arterial bypass graft models

We report methods for (a) transforming a three-dimensional geometry acquired by magnetic resonance angiography (MRA) in vivo, or by imaging a model cast, into a computational surface representation, (b) use of this to construct a three dimensional numerical grid for computational fluid dynamic (CFD) studies, and (c) use of the surface representation to produce a stereo-lithographic replica of the real detailed geometry, at a scale convenient for detailed magnetic resonance imaging (MRI) flow studies. This is applied to assess the local flow field in realistic geometry arterial bypass grafts. Results from a parallel numerical simulation and MRI measurement of flow in an aorto-coronary bypass graft with various inlet flow conditions demonstrate the strong influence of the graft inlet waveform on the perianastomotic flow field. A sinusoidal and a multi harmonic coronary flow waveform both with a mean Reynolds number (Re) of 100 and a Womersley parameter of 2.7 were applied at the graft inlet. A weak axial flow separation region just distal to the toe was found in sinusoidal flow near end deceleration (Re = 25). At the same location and approximately the same point in the cycle (Re = 30) but in coronary flow, the axial flow separation was stronger and more spatially pronounced. No axial flow separation occurred in steady flow for Re = 100. Numerical predictions indicate a region in the vicinity of the suture line (where there is a local narrowing of the graft) with a wall shear magnitude in excess of five times that associated with fully developed flow at the graft inlet.

Bactericidal properties of ozone and its potential application as a terminal disinfectant

The efficacy of ozone as a terminal disinfectant was evaluated under laboratory conditions. Different microorganisms of importance to the food industry were inoculated onto stainless steel squares and incubated at various temperatures and relative humidities for up to 4 h. Survival of microorganisms from these controls was compared with identically incubated squares exposed to ozone. Exposure of the contaminated surfaces to ozone (2 ppm for 4 h) resulted in a reduction in microbial viability that ranged, depending on organism type, from 7.56 to 2.41 log values. For all the microorganisms tested, this loss in viability was significantly greater (P < 0.05) than that observed in the absence of ozone. Gram-negative bacteria were more sensitive to ozone than gram-positive organisms; bacteria were more sensitive than the yeast strain tested. Exposure to ozone (2 ppm for 4 h) in the presence of ultra-high temperature (UHT) milk resulted in a reduction in bacterial viability that ranged from 5.64 to 1.65 log values. In most cases, this reduction was significantly less (P < 0.05) than that achieved in the absence of organic material, although still significantly greater (P < 0.05) than that observed in the absence of ozone. The presence of a meat-based broth reduced the effectiveness of ozone to a greater extent, although the number of surviving gram-negative organisms was still significantly less (P < 0.05) than in the absence of ozone. Less than 1 log unit of yeast cells was destroyed when exposed to ozone in the presence of UHT milk or meat-based broth. Results of this investigation suggest that if applied after adequate cleaning ozone could be used as an effective disinfectant.

Clinical relevance of in vitro propagation of activated lymphocytes from endomyocardial biopsy samples of pediatric heart transplant recipients

In vivo activated T-lymphocytes can be cultured from endomyocardial biopsy samples of human cardiac allografts, sometimes even in the absence of histological rejection. We investigated the clinical relevance of this "lymphocyte growth assay" in pediatric heart transplant recipients. Specifically, we wished to determine if: (i) positive lymphocyte growth from EMB samples in the absence of significant rejection identifies a patient as being at increased risk for the development of acute rejection; (ii) withdrawal or major dose reduction of corticosteroids in the presence of lymphocyte growth results in high risk of rebound rejection; and (iii) presence of lymphocyte growth during acute rejection helps predict the response to treatment. Cultures were performed on 789 consecutive EMB samples from 65 pediatric heart transplant recipients in media containing 30 U/ml of recombinant IL-2. T-lymphocytes were cultured from 16% of EMB samples with low grade rejection (grade 0-1b) and from 34% of EMB samples with grade 2-4 rejection. EMB samples obtained early post-transplant (<180 days) were significantly more likely to yield positive lymphocyte growth compared to biopsies obtained late for any given rejection grade. Lymphocyte growth was comparable between patients managed with cyclosporine or tacrolimus based immunosuppression. For 227 EMB samples without rejection, a subsequent EMB sample was obtained within 12 weeks. Lymphocyte cultures were positive in 47 of these 227 EMB samples (21%), and in 19 out of 47 (40%) cases acute rejection (grade 2-4) was present on the follow-up EMB sample. By contrast, of 180 biopsies without growth, only 29 (16%) showed rejection at the next EMB (p<0.0001). When a follow-up biopsy was performed within 12 weeks of corticosteroid withdrawal, "rebound rejection" was observed in 3 out of 10 (30%) cases where the previous EMB sample yielded positive lymphocyte growth and in 4 out of 38 (11%) cases when it did not (p=0.29). The presence of lymphocyte growth in association with rejection was also predictive of whether rejection would resolve following high dose intravenous corticosteroid therapy (persistent rejection in 33 out of 50 (66%) cases with positive growth, versus 25 out of 80 (31%) cases without growth (p<0.0001)). Thus, positive lymphocyte growth is strongly associated with higher grade of rejection and earlier time from transplantation. Lymphocyte growth in the absence of rejection indicates high risk for rejection within the next 12 weeks. Growth in association with acute rejection indicates high probability of persistence of rejection following treatment with high dose corticosteroids.

A 50-year perspective upon selective gastric vagotomy

BACKGROUND

The occurrence of postvagotomy complications was initially considered an unavoidable but acceptable consequence of duodenal ulcer surgery. Following the description of "selective" vagotomy procedures, however, it became apparent that effective ulcer surgery might be accomplished without unpleasant sequellae.

METHODS

In 1957 the experimental basis for "highly" selective vagotomy (HSV), which preserved antral innervation, was reported. HSV was performed in several European centers between 1960 and 1968, and was widely accepted there. Surgeons in the United States, in contrast, were largely reluctant to use HSV, an operation which had an excessive ulcer recurrence rate compared to vagotomy-antrectomy. More recently, HSV is recognized as a successful operation, due to more complete division of preganglionic gastric vagal nerves ("extended" HSV) and the liberal use of pyloric reconstruction in patients with juxtapyloric ulcers.

RESULTS

HSV is performed with minimal morbidity, with an incidence of recurrent ulcer which is less than 5%. Complications such as dumping, diarrhea, and gastric atony are quite rare.

CONCLUSIONS

HSV is an ideal procedure for most patients with duodenal ulcer. Because most operations for ulcer are performed for urgent or life-threatening problems, the most common operation performed in the United States today is truncal vagotomy combined with pyloroplasty or gastric resection. Earlier operation for chronic ulcer has many potential advantages.

Tumour bed biopsy detects the presence of multifocal disease in patients undergoing breast conservation therapy for primary breast carcinoma

This study prospectively examined tumour bed biopsies in 135 consecutive patients undergoing conservative surgery for breast carcinoma. All had wide resection of the primary tumour and histologically clear margins. Twelve patients (9%) had positive tumour bed biopsies. Two subgroups of patients had positive bed biopsies; those with ductal carcinoma in situ, and a second group with more aggressive disease characterized by lymph node involvement, vascular invasion and a higher grade and mitotic count. As the majority of recurrences from breast carcinoma occur in the region of the primary tumour, bed biopsy may aid in the identification of a group of patients with multifocal or aggressive disease who are at increased risk of local recurrence.

The structured clinical instruction module: a novel strategy for improving the instruction of clinical skills

We have previously shown that both medical students and residents demonstrate numerous important deficits when evaluating patients with abdominal complaints. To address these deficits, we implemented a pilot instructional program derived from the Objective Structured Clinical Examination. Fifty third-year medical students were presented with a 1-hr Structured Clinical Instruction Module (SCIM) of five stations, each station addressing a different aspect of the surgical evaluation of the abdomen. Simulated patients were present at two of the stations. Faculty from appropriate disciplines were present at the stations to provide standardized instruction according to predetermined curricular objectives. The medical students evaluated the SCIM for its specific characteristics, and they evaluated each of the five stations for its efficacy in increasing their clinical skills. All the specific aspects of the SCIM were given a rating significantly higher than neutral (P < 0.0001). Students agreed most strongly that the faculty were well prepared for the SCIM and that the faculty were enthusiastic. All of the SCIM stations were given a rating significantly higher than average (P < 0.0001). When compared to a conventional workshop, the SCIM scored significantly higher on all three common evaluation items. The SCIM was very well received by medical students as a format for clinical instruction. This unique modification of the Objective Structured Clinical Examination has potential for teaching important clinical skills that are not consistently mastered within current surgical curricula.

Collision of comet Shoemaker-Levy 9 with Jupiter observed by the NASA infrared telescope facility

The National Aeronautics and Space Administration (NASA) Infrared Telescope Facility was used to investigate the collision of comet Shoemaker-Levy 9 with Jupiter from 12 July to 7 August 1994. Strong thermal infrared emission lasting several minutes was observed after the impacts of fragments C, G, and R. All impacts warmed the stratosphere and some the troposphere up to several degrees. The abundance of stratospheric ammonia increased by more than 50 times. Impact-related particles extended up to a level where the atmospheric pressure measured several millibars. The north polar near-infrared aurora brightened by nearly a factor of 5 a week after the impacts.

Human spleen cells mediating natural killing: altered natural cytotoxicity of spleen effector cells from patients with carcinoma

Spleen cells from eight patients with abdominal carcinoma and six patients undergoing major surgery for a variety of disease entities were assayed for natural cytotoxicity towards 51Cr-labelled K 562 target cells. Patients with abdominal cancer were shown to have relatively weak splenic natural cytotoxicity compared with the reactivity of effector cells from non-carcinoma patients. Nylon wool non-adherent spleen effector cells from cancer patients showed reduced cytolytic capacity compared with effector cells prepared from the spleens of other patients or peripheral blood mononuclear cells (PBMC) obtained from healthy individuals, whereas the splenic reactivity of non-cancer patients showed the same nylon wool separation profile as PBMC, high cytolytic activity being associated with nylon wool non-adherent effector cells. Splenic effector cell cytotoxicity from cancer and non-cancer patients was enhanced following exposure to human interferon, and inhibited by treatment with cholera toxin and simple sugars. Furthermore, fractionation of spleen cells on Percoll discontinuous density gradients demonstrated natural cytotoxic activity to reside predominantly in the low density cell fractions, similar to that found with NK cells from peripheral blood. Thus the properties described here for human cytotoxic spleen cells are similar to those described for peripheral blood NK cells, suggesting these two effector cell populations to be closely related, if not identical.

Bupropion: clinical assay for amphetamine-like abuse potential

Bupropion hydrochloride (100, 200, and 400 mg), d-amphetamine sulfate (15 and 30 mg), and placebo were compared in 13 volunteers who had histories of amphetamine abuse. Each dose was given orally at intervals of 3 or more days according to a double-blind, randomized crossover design. Bupropion had little or no effect on blood pressure, pulse rate, respiration, body temperature, pupil diameter, subjective appetite, food intake, sleep, or selected subscales of the Addiction Research Center Inventory and Single Dose Questionnaire. Conversely, d-amphetamine was active on most measures. It is concluded that, despite bupropion's reinforcing properties in animals, the compound is not amphetamine-like and is unlikely to give rise to such abuse in humans.