High-throughput sequencing of insect specimens with sub-optimal DNA preservation using a practical, plate-based Illumina-compatible Tn5 transposase library preparation method

Entomological sampling and storage conditions often prioritise efficiency, practicality and conservation of morphological characteristics, and may therefore be suboptimal for DNA preservation. This practice can impact downstream molecular applications, such as the generation of high-throughput genomic libraries, which often requires substantial DNA input amounts. Here, we use a practical Tn5 transposase tagmentation-based library preparation method optimised for 96-well plates and low yield DNA extracts from insect legs that were stored under sub-optimal conditions for DNA preservation. The samples were kept in field vehicles for extended periods of time, before long-term storage in ethanol in the freezer, or dry at room temperature. By reducing DNA input to 6ng, more samples with sub-optimal DNA yields could be processed. We matched this low DNA input with a 6-fold dilution of a commercially available tagmentation enzyme, significantly reducing library preparation costs. Costs and workload were further suppressed by direct post-amplification pooling of individual libraries. We generated medium coverage (>3-fold) genomes for 88 out of 90 specimens, with an average of approximately 10-fold coverage. While samples stored in ethanol yielded significantly less DNA compared to those which were stored dry, these samples had superior sequencing statistics, with longer sequencing reads and higher rates of endogenous DNA. Furthermore, we find that the efficiency of tagmentation-based library preparation can be improved by a thorough post-amplification bead clean-up which selects against both short and large DNA fragments. By opening opportunities for the use of sub-optimally preserved, low yield DNA extracts, we broaden the scope of whole genome studies of insect specimens. We therefore expect these results and this protocol to be valuable for a range of applications in the field of entomology.

Novel therapeutics in low-grade serous ovarian cancer

Low-grade serous ovarian cancer is a rare subtype of epithelial ovarian cancer clinically characterized by younger age at diagnosis, relative chemoresistance, and prolonged survival compared with its high-grade serous counterpart. It is molecularly characterized by estrogen and progesterone receptor positivity, aberrations in the MAPK (mitogen-activated protein kinase) pathway, and wild-type TP53 expression pattern. As research into low-grade serous ovarian cancer as a distinct entity has been able to accelerate independently, we have learned more about its unique pathogenesis, oncogenic drivers, and opportunities for novel therapeutics. In the primary setting, cytoreductive surgery in combination with platinum-based chemotherapy remain the standard of care. However, low-grade serous ovarian cancer has demonstrated relative chemoresistance in the primary and recurrent settings. Endocrine therapy is also commonly utilized in the maintenance and recurrent settings and is being evaluated in the adjuvant setting. Given the many similarities of low-grade serous ovarian cancer to luminal breast cancer, many recent studies have utilized similar therapeutic strategies including endocrine therapy combinations with CDK (cyclin-dependent kinase) 4/6 inhibitors. Additionally, recent trials have investigated combination therapies targeting the MAPK pathway, including MEK (mitogen-activated protein kinase kinase), BRAF (v-raf murine sarcoma viral oncogene homolog B1), FAK (focal adhesion kinase), and PI3K (phosphatidylinositol 3-kinase) inhibition. In this review, we will outline these novel therapeutic strategies for low-grade serous ovarian cancer.

A cross-sectional study of the prevalence of anal dysplasia among women with high-grade cervical, vaginal, and vulvar dysplasia or cancer: The PANDA Study

BACKGROUND

High-risk HPV (HR-HPV) infection is a risk factor for anal cancer, yet no anal cancer screening guidelines exist for women with lower genital tract HPV-related disease. We sought to describe the prevalence of anal HR-HPV or cytologic abnormalities in such women.

METHODS

This cross-sectional study was performed between October 2018 and December 2021. Inclusion criteria were >21 years of age and a prior diagnosis of high-grade dysplasia/cancer of the cervix, vagina, or vulva. Participants underwent anal cytology and anal/cervicovaginal HR-HPV testing. Women with abnormal anal cytology were referred for high-resolution anoscopy (HRA).

RESULTS

324 evaluable women were enrolled. Primary diagnosis was high-grade dysplasia/cancer of the cervix (77%), vagina (9%), and vulva (14%). Anal HR-HPV was detected in 92 patients (28%) and included HPV-16 in 24 (26%), HPV-18 in 6 (7%), and other HR-HPV types in 72 (78%) patients. Anal cytology was abnormal in 70 patients (23%) and included ASCUS (80%), LSIL (9%), HSIL (1%), and ASC-H (10%). Of these patients, 55 (79%) underwent HRA. Anal biopsies were performed in 14 patients: two patients had AIN 2/3, one patient had AIN 1, and 11 patients had negative biopsies. Both patients with AIN 2/3 had a history of cervical dysplasia.

CONCLUSION

Our results suggest an elevated risk of anal HR-HPV infection and cytologic abnormalities in women with lower genital tract dysplasia/cancer.

IMPACT

These results add to the growing body of evidence suggesting the need for evaluation of screening methods for anal dysplasia/cancer in this patient population to inform evidence-based screening recommendations.

Abstract 4135: Initial clinicopathologic and molecular characterization of minimal residual disease detected by second look laparoscopy after completion of frontline surgery and chemotherapy in patients with advanced stage ovarian cancer

Background: Despite high rates of remission after frontline management, most patients with advanced stage ovarian cancer recur. Second look laparoscopy (SLL) can provide more sensitive detection of minimal residual disease (MRD) allowing for more individualized prognostication and possible therapeutic intervention. It may also assess tumor biology and microenvironment associated with undetectable chemoresistant MRD phase of ovarian cancer. The objective of this study was to determine SLL feasibility, and clinicopathologic and molecular characteristics of MRD after frontline therapy in ovarian cancer.

Methods: SLL was offered to patients with stage III-IV high grade epithelial ovarian cancer who achieved complete response after frontline surgery and 6 cycles of carboplatin and paclitaxel chemotherapy. Patients were offered standard of care or investigational management options based on homologous recombination deficiency (HRD) and MRD status at SLL. Preliminary translational studies included RNAseq for comparison of serial, matched tumor from primary or interval TRS and SLL derived MRD+ biopsies at the time of SLL. In addition, Nanostring analyses of SLL surgical biopsies both with and without residual tumor were performed. Molecular profiling employed hierarchical clustering, principle component analysis, non-parametric testing, and pathway analyses.

Results: Between 4/2017- 7/2021, 39 patients underwent SLL. The majority had stage III disease (74%), high grade serous histology (90%) and underwent neoadjuvant chemotherapy with interval tumor reductive surgery (TRS; 54%). MRD was present in 49% (n=19) of patients and was more frequent among neoadjuvant chemotherapy recipients (73% vs 26%, P=0.015) and patients with homologous recombination proficient tumors (81% vs 25%, P=0.01). Most patients without MRD were dispositioned to observation; 4 patients with HRD received a PARP inhibitor per standard of care. All other patients with MRD received bevacizumab as part of a clinical trial, except for one patient who received a PARP inhibitor. Median follow-up was 6.74 months (range 0.66 - 28.62). Presence of MRD was associated with worse PFS (HR 3.7, 95% CI 1.3- 10.9; 5.5 vs 24.6 months; P= 0.02). Based on transcriptional signature, MRD are immunologically distinct from untreated tumors or those collected at interval TRS (after 3 cycles of chemo) but also displayed heterogeneity with two distinct subclusters.

Conclusions: SLL to assess for MRD has potential to further individualize post-frontline therapy, and identify patients at high risk for progression for early intervention clinical trials. Transcriptional profiling suggests that MRD phase of ovarian cancer is characterized by a distinct, heterogeneous, and evolving tumor and immune microenvironment.

Citation Format: Roni Nitecki, Minghao Dang, Sanghoon Lee, Bryan Fellman, J Alejandro Rauh-hain, Jolyn Taylor, Lois Ramondetta, Michaela Grinsfelder, Lauren Cobb, David M. Boruta, Pamela T. Soliman, Aaron Shafer, Nicole D. Fleming, Shannon N. Westin, Anil K. Sood, Chris Tanguma, Pedro T. Ramrez, Karen H. Lu, Linghua Wang, Amir A. Jazaeri. Initial clinicopathologic and molecular characterization of minimal residual disease detected by second look laparoscopy after completion of frontline surgery and chemotherapy in patients with advanced stage ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4135.

Correlation of surgeon radiology assessment with laparoscopic disease site scoring in patients with advanced ovarian cancer

BACKGROUND

Radiographic triage measures in patients with new advanced ovarian cancer have yielded inconsistent results.

OBJECTIVE

To determine the correlation between surgeon radiology assessment and laparoscopic scoring by disease sites in patients with newly diagnosed advanced stage ovarian cancer.

METHODS

Fourteen gynecologic oncology surgeons from a single institution performed a blinded review of pre-operative contrast-enhanced CT imaging from patients with advanced stage ovarian cancer. Each of the patients had also undergone laparoscopic scoring assessment, between April 2013 and December 2017, to determine primary resectability using the validated Fagotti scoring method, and assigned a predictive index value score. Surgeons were asked to provide expected predictive index value scores based on their blinded review of the antecedent CT imaging. Linear mixed models were conducted to calculate the correlation between radiologic and laparoscopic score for surgeons individually, and as a group. Once the model was fit, the inter-class correlation and 95% CI were calculated.

RESULTS

Radiology review was performed on 20 patients with advanced stage ovarian cancer who underwent laparoscopic scoring assessment. Surgeon faculty rank included assistant professor (n=5), associate professor (p=4), and professor (n=5). The kappa inter-rater agreement was -0.017 (95% CI -0.023 to -0.005), indicating low inter-rater agreement between radiology review and actual laparoscopic score. The inter-class correlation in this model was 0.06 (0.02-0.21), indicating that surgeons do not score the same across all the images. When using a clinical cut-off point for the predictive index value of 8, the probability of agreement between radiology and actual laparoscopic score was 0.56 (95% CI 0.49 to 0.73). Examination of disease site sub-scales showed that the probability of agreement was as follows: peritoneum 0.57 (95% CI 0.51 to 0.62), diaphragm 0.54 (95% CI 0.48 to 0.60), mesentery 0.51 (95% CI 0.45 to 0.57), omentum 0.61 (95% CI 0.55 to 0.67), bowel 0.54 (95% CI 0.44 to 0.64), stomach 0.71 (95% CI 0.65 to 0.76), and liver 0.36 (95% CI 0.31 to 0.42). The number of laparoscopic scoring cases, tumor reductive surgery cases, or faculty rank was not significantly associated with overall or sub-scale agreement.

CONCLUSIONS

Surgeon radiology review did not correlate highly with actual laparoscopic scoring assessment findings in patients with advanced stage ovarian cancer. Our study highlights the limited accuracy of surgeon radiographic assessment to determine resectability.

Reduction in opioid use and postoperative pain scores after elective laparotomy with implementation of enhanced recovery after surgery protocol on a gynecologic oncology service

Objective

Enhanced Recovery After Surgery (ERAS) protocols are designed to mitigate the physiologic stress response created by surgery, to decrease the time to resumption of daily activities, and to improve overall recovery. This study aims to investigate postoperative recovery outcomes following gynecologic surgery before and after implementation of an ERAS protocol.

Methods

A retrospective chart review was performed of patients undergoing elective laparotomy at a major academic center following implementation of an ERAS protocol (11/4/2014–7/27/2016) with comparison to a historical cohort (6/23/2013–9/30/2014). The primary outcome was length of hospital stay. Secondary outcomes included surgical variables, time to recovery of baseline function, opioid usage, pain scores, and complication rates. Statistical analyses were performed using Wilcoxon rank sum, Fisher’s exact, and chi squared tests.

Results

One hundred and thirty-three women on the ERAS protocol who underwent elective laparotomy were compared with 121 historical controls. There was no difference in length of stay between cohorts (median 4 days; P = 0.71). ERAS participants had lower intraoperative (45 vs 75 oral morphine equivalents; P < 0.0001) and postoperative (45 vs 154 oral morphine equivalents; P < 0.0001) opioid use. ERAS patients reported lower maximum pain scores in the post-anesthesia care unit (three vs six; P < 0.0001) and on postoperative day 1 (four vs six; P = 0.002). There was no statistically significant difference in complication or readmission rates.

Conclusions

ERAS protocol implementation was associated with decreased intraoperative and postoperative opioid use and improved pain scores without significant changes in length of stay or complication rates.

Carcinogenicity of radon/radon decay product inhalation in rats--effect of dose, dose rate and unattached fraction

PURPOSE

The effects of inhalation of radon/radon decay products at different total doses, dose rates and 'unattached' fractions were investigated in a life span study in rats.

MATERIALS AND METHODS

1574 rats inhaled radon/radon decay products in a purpose-built recirculating exposure system that provided stable/reproducible exposure conditions. 501 were maintained as controls.

RESULTS

Lung tumour incidences were significantly elevated in most exposed groups. The study power was insufficient to resolve the shape of the dose and dose rate response curves, but combination of this data with that from other studies demonstrated that for high cumulative exposures, the lifetime excess absolute risk increases with increasing exposure durations and for low cumulative exposures the opposite trend occurs. Exposure did not increase leukaemia incidences. A small number of non-lung tumour types including mammary fibroadenoma showed elevated incidences in some exposed groups, however not consistently across all exposure groups and showed no dose or dose rate relationship.

CONCLUSIONS

Radon/radon decay product exposure caused excess lung tumours in rats along with limited non-lung effects. The results are consistent with the findings that at low cumulative exposures decreasing exposure concentrations or protracting the time over which the dose is delivered, reduces lung tumour risk. At higher levels, decreasing exposure concentrations or protracting exposure time increases lung tumour risk.

Cardiac arrest in medical and dental practices: implications for automated external defibrillators

BACKGROUND

To determine the need for placing automated external defibrillators (AEDs) in medical and dental practices, we identified cardiac arrests at these locations.

METHODS

Locations of cardiac arrest were abstracted from Emergency Medical Services data from January 1, 1990, through December 31, 1996. We calculated the annual incidence of cardiac arrest per type of practice.

RESULTS

There were 142 cardiac arrests in medical or dental practices. Dialysis centers had a relatively high incidence of cardiac arrest (>/=0.746 per practice annually). Cardiology, internal and family medicine, and urgent care centers had a medium incidence (>/=0.01 per practice annually). All other medical and dental practices had a low incidence (</=0.002 annually).

CONCLUSIONS

Placement of 779 AEDs in the high- and medium-incidence practices would have provided treatment for 112 patients with cardiac arrest in 7 years. To provide for the 16 cardiac arrests in low-incidence practices, an additional 1928 AEDs would be required.

U.S. clinical investigation of the Artisan myopia lens for the correction of high myopia in phakic eyes. Report of the results of phases 1 and 2, and interim phase 3

PURPOSE

The purpose of this article is to present the results of the U.S. Clinical investigation of the Artisan anterior chamber iris fixed lens implant for the correction of myopia in phakic eyes.

METHODS

A prospective, multi-center, FDA-supervised trial was designed and undertaken in the United States by Ophtec USA, Inc., Boca Raton, Florida to determine the safety and efficacy of the Artisan lens as a potential refractive treatment for patients with high myopia. During the trial, two different models of the Artisan lens were used: one with a 5-mm optical zone (model 206) and the other with a 6-mm optical zone (model 204).

RESULTS

The data presented comprise 176 enrolled subjects and 264 implant procedures. The most frequently chosen Artisan lens power was -13.00 D (average, -12.76 D; SD, 3.24). The postoperative results at 6 months for all eyes (n = 135) showed 100% of patients were 20/40 or better best-corrected while 72% gained one or more lines and 22% gained two or more lines regardless of degree of astigmatism or postoperative goal. Through the course of the study, intraocular pressure maintained a level with a mean below 16 mmHg. In general, total reported complications in the patient cohort decreased over time, dropping from 39% at the initial visit to 10% at visit four and 0% at visit seven.

CONCLUSIONS

On the basis of the interim results of the U.S. Clinical Investigation of the Artisan Myopia Lens for the Correction of High Myopia in Phakic Eyes, the Artisan anterior chamber phakic IOL may offer an option for correction of high degrees of myopia. Refractive outcomes were exceptional and complications were minimal and amenable to treatment.

Cardiopulmonary resuscitation by chest compression alone or with mouth-to-mouth ventilation

BACKGROUND

Despite extensive training of citizens of Seattle in cardiopulmonary resuscitation (CPR), bystanders do not perform CPR in almost half of witnessed cardiac arrests. Instructions in chest compression plus mouth-to-mouth ventilation given by dispatchers over the telephone can require 2.4 minutes. In experimental studies, chest compression alone is associated with survival rates similar to those with chest compression plus mouth-to-mouth ventilation. We conducted a randomized study to compare CPR by chest compression alone with CPR by chest compression plus mouth-to-mouth ventilation.

METHODS

The setting of the trial was an urban, fire-department-based, emergency-medical-care system with central dispatching. In a randomized manner, telephone dispatchers gave bystanders at the scene of apparent cardiac arrest instructions in either chest compression alone or chest compression plus mouth-to-mouth ventilation. The primary end point was survival to hospital discharge.

RESULTS

Data were analyzed for 241 patients randomly assigned to receive chest compression alone and 279 assigned to chest compression plus mouth-to-mouth ventilation. Complete instructions were delivered in 62 percent of episodes for the group receiving chest compression plus mouth-to-mouth ventilation and 81 percent of episodes for the group receiving chest compression alone (P=0.005). Instructions for compression required 1.4 minutes less to complete than instructions for compression plus mouth-to-mouth ventilation. Survival to hospital discharge was better among patients assigned to chest compression alone than among those assigned to chest compression plus mouth-to-mouth ventilation (14.6 percent vs. 10.4 percent), but the difference was not statistically significant (P=0.18).

CONCLUSIONS

The outcome after CPR with chest compression alone is similar to that after chest compression with mouth-to-mouth ventilation, and chest compression alone may be the preferred approach for bystanders inexperienced in CPR.

Above reproach: developing a comprehensive ethics and compliance program

How can a healthcare organization improve the public's confidence in the conduct of its business operations? What can it do to ensure that it can thrive despite being the subject of public and governmental scrutiny and doubt? Healthcare providers must establish standards of conduct that are above reproach and ensure that those standards are clearly articulated and strictly adhered to. This article describes the merits of a comprehensive ethics and compliance program, suggests five basic elements of such a program--organizational support/structure, setting standards, creating awareness, establishing a mechanism for reporting exceptions, and monitoring and auditing--and then demonstrates how those elements should be applied in several high-risk areas. Fundamentally, an ethics and compliance program has two purposes: to ensure that all individuals in an organization observe pertinent laws and regulations in their work; and to articulate a broader set of aspirational ethical standards that are well-understood within the organization and become a practical guideline for organization members making decisions that raise ethical concerns. Every ethics and compliance program should contain certain fundamental aspects. First, the effort must have the active support of the most senior management in the organization. To instill a commitment to ethics and compliance absent a clear and outspoken commitment to such purposes by organization leaders is simply impossible. Second, an ethics and compliance program is fundamentally about organizational culture--about instilling a commitment to observe the law and, more generally, to do the right thing. Third, ethics and compliance are responsibilities of operating management (sometimes called line management). Although staff such as compliance officers are obligated to provide the necessary resources for a successful program and to design the program, such staff officers cannot achieve implementation and execution. Only operating managers can do that. Fourth, an ethics and compliance effort should be about the conduct of individuals, not about "checking the boxes" in a model plan or generating attractive written or educational materials. Such an effort is about individuals on a day-to-day basis knowing what is expected of them and doing it and about never compromising integrity, regardless of pressures faced. A great deal of progress has been made in healthcare organizations in the development of increasingly sophisticated ethics and compliance programs. A particularly energetic focus has been placed on these programs since formal government guidance regarding compliance programs was first issued in the laboratory area about two years ago and as more sophisticated automated monitoring tools have been developed. As ethics and compliance programs have become more sophisticated, certain best practices have been established. This discussion will set forth approaches to ethics and compliance in the context of what are believed to be illustrative best practices. Much of what is described here is descriptive of the efforts of Columbia/HCA Healthcare Corporation from October 1997 to the present; however, this article has been presented not as a mere descriptive piece but rather as a set of normative guidelines. We hope that other healthcare providers will find this to be of practical use. Provider settings pose certain unique challenges that are specifically addressed in this discussion; however, many of the issues raised can be adapted to other healthcare organizations. For simplicity's sake, because the authors of this article all work on a daily basis primarily with hospitals, the article is written from a hospital perspective.

Imprinting of distal mouse chromosome 2 is associated with phenotypic anomalies in utero

Previous studies have shown that the distal region on mouse chromosome (Chr) 2 is subject to imprinting as mice with maternal duplication/paternal deficiency (MatDp.dist2) and the reciprocal (PatDp.dist2) for this region exhibit phenotypic anomalies at birth and die neonatally. We show here that imprinting effects are detectable in utero. Notably PatDp.dist2 embryos show an increase in wet weight compared with normal, which peaks at 16.5 d post coitum (dpc), and diminishes by birth, whereas the wet weight of placenta is slightly reduced in the latter half of gestation. Newborns have increased length of the long bones. By contrast, the wet weight of MatDp.dist2 embryos decreases during the second half of gestation. Measurements of dry weights of embryos at 16.5 dpc have indicated that there is no difference in either PatDp.dist2 or MatDp.dist2 compared with normal so that the wet weight differences are due to fluid retention in PatDp.dist2 but fluid loss in MatDp.dist2. In PatDp.dist2 embryos excess fluid is particularly prominent in the subcuticular skin layer, whereas by birth fluid is evident around the neck and tongue. At 16.5 dpc the PatDp.dist2 embryos are severely oedematous, as the average fluid content per unit dry weight per embryo was increased by 40%, whereas the MatDp.dist2 embryos are dehydrated as the average water content per unit dry weight per embryo was reduced by 6%. A preliminary conclusion is that there is neither growth enhancement in PatDp.dist2 nor growth retardation in MatDp.dist2 offspring.

Covering the "open abdomen": a better technique

"Damage control" in severe abdominal trauma, abdominal compartment syndrome, necrotizing fasciitis of the abdominal wall, and necrotizing pancreatitis often preclude closure of the fascia after laparotomy. Many techniques have been reported for temporary coverage of the exposed viscera, but most have had documented problems. We report the successful use, since 1989, of a temporary sutureless coverage. The viscera are covered with omentum when possible, then with a clear plastic sheet. Sump drains are placed over this layer. The entire abdomen is then covered with two layers of iodophor-impregnated adhesive plastic drape. The last 50 patients managed with this technique are reported. The most common indication (27 patients) was for treatment of severe abdominal trauma. There were no wound infections, fasciitis, or bowel obstruction. Eighteen patients died; no deaths were related to abdominal closure. Temporary abdominal covering with adhesive plastic sheeting is a rapid, safe, and readily available method for managing the open abdomen. This technique provides a physiologic milieu for the abdominal viscera, simplifies nursing care, and promotes safe closure of the abdomen at a later time.

Investigation of lung tumour induction in C3H/HeH mice, with and without tumour promotion with urethane, following paternal X-irradiation

In series of papers Nomura has reported that parental irradiation can lead to an enhanced incidence of lung and other tumours. However, in a recent study with BALB/cJ mice, using optimum conditions as defined by Nomura, we were unable to confirm this. We have now repeated the investigation using a different inbred strain, C3H/HeH, with and without tumour promotion in the F1 by urethane, again using protocols defined by Nomura. In a series of replicate studies spanning over 2 years, males were exposed to single, acute doses of 0, 250 and 500 cGy X-rays and thereafter placed with two females each in each of two consecutive weeks. Half the offspring from each treatment group and each week of mating were given 5 mmol/kg body weight of the urethane, while the remainder remained untreated. Most of the offspring produced were killed and scored for lung tumours at 6 months of age, while the rest were examined at 12 months of age. The proportion of fertile females and litter size provided evidence of a dose-dependent mutational response to the paternal irradiation, but no trace of a radiation-enhanced lung tumour incidence was detected among the progeny, whether in the urethane or non-urethane groups at 6 or 12 months of age, and whether assessed by numbers of mice with tumours, clusters of tumours, or cluster size. As seen in the BALB/cJ study, significant differences among different replicates were found, again suggesting a cyclical or seasonal variation in tumour incidence, but the variations seen with the two strains were not the same. The need for concurrent controls for tumour work was, nevertheless, again indicated. The overall findings do not therefore accord with those of Nomura. Furthermore, they do not support the causal association between the raised incidence of childhood leukaemia and non-Hodgkins lymphoma near Sellafield and the father's recorded radiation exposure during employment in the nuclear industry, as suggested by the Gardner report.

Public locations of cardiac arrest. Implications for public access defibrillation

BACKGROUND

The purpose of this study was to describe the public locations of cardiac arrest and to estimate the annual incidence of cardiac arrest per site to determine optimal placement of automatic external defibrillators (AEDs). This was a retrospective cohort study.

METHODS AND RESULTS

Locations of cardiac arrest were abstracted from data collected by emergency medical service programs in Seattle and King County, Washington, from January 1, 1990, through December 31, 1994. Types of commercial and civic establishments were tallied and grouped into 23 location categories consistent with Standard Industrial Codes, and the number of sites within each location category was determined. With the addition of "public outdoors" and "automobiles" as categories, there were 25 location categories. During the study period, 7185 arrests occurred, 1130 (16%) of which were in public locations. An annual incidence of cardiac arrest per site was calculated. Ten location categories with 172 sites were identified as having a higher incidence of cardiac arrest (> or = .03 per year per site). Thirteen location categories had a lower incidence of arrest (< or = .01 per year per site). There were approximately 71,000 sites within these categories.

CONCLUSIONS

Placement of 276 AEDs in the 172 higher-incidence sites would have provided treatment for 134 cardiac arrest patients in a 5-year period, 60% of whom were in ventricular fibrillation. We estimate between 8 and 32 lives could be saved in 5 years. To cover the remaining 347 arrests occurring in public in a 5-year period, defibrillators would have to be placed in 71,000 sites, not including outdoors and automobiles. Placement of AEDs in public locations can be guided by the site-specific incidence of arrest.

Diastolic blood pressure and the risk of primary cardiac arrest among pharmacologically treated hypertensive patients

BACKGROUND

Previous studies have raised the concern that the reduction of diastolic blood pressure below 85 mm Hg among treated hypertensive patients may have cardiac hazards. However, these reports have not fully assessed potential confounding from coexisting cardiovascular disease.

METHODS

We conducted a population-based case-control study to examine the relation between treated diastolic blood pressure and the risk of primary cardiac arrest among hypertensive patients free of clinically diagnosed cardiovascular disease. Cases were hypertensive enrollees of the Group Health Cooperative of Puget Sound, an HMO, who had primary cardiac arrest between 1977 and 1990 (n = 80). Control patients were a stratified random sample of hypertensive enrollees (n = 426). Ambulatory-care records were reviewed to assess blood pressures and other clinical characteristics. Medication use was assessed through the HMO computerised pharmacy database.

RESULTS

Logistic regression models suggested a curvilinear relation between the level of treated diastolic blood pressure and the risk of primary cardiac arrest, after adjustment for pretreatment diastolic blood pressure, antihypertensive therapy, and other potential confounders. Compared with a treated diastolic blood pressure of 85 mm Hg, a treated diastolic blood pressure of 80 mm Hg was associated with a small increase in risk (relative risk [RR] 1.2; 95% confidence interval [CI] 1.0, 1.6), 75 mm Hg was associated with a modest increase in risk [RR 1.6; 95% CI 1.2, 2.1], and 70 mm Hg was associated with more than a twofold increase in the risk of primary cardiac arrest [RR 2.3; 95% CI 1.4; 3.8). There was little evidence of effect modification by pretreatment diastolic blood pressure.

CONCLUSIONS

Our findings support available evidence that among hypertensive patients a treated diastolic blood pressure level below 85 mm Hg is associated with cardiac hazards.

Segregation of pANCA antigenic recognition by DNase treatment of neutrophils: ulcerative colitis, type 1 autoimmune hepatitis, and primary sclerosing cholangitis

Antineutrophil cytoplasmic antibodies (ANCA) have been identified in the serum of 50-80% of ulcerative colitis (UC) patients. UC-associated ANCA yield a perinuclear staining pattern (pANCA) with alcohol-fixed neutrophils. More recently, pANCA have been detected in the serum of patients with primary sclerosing cholangitis (PSC) and other autoimmune liver diseases. Up to 70% of PSC patient sera and up to 92% of sera from patients with well-defined type 1 autoimmune hepatitis (type 1 AIH) were found to express pANCA. Such expression by patients with PSC and type 1 AIH raises questions concerning the relationship of these pANCA to each other and to that of UC. Differences and similarities in pANCA characteristics are found among the three diseases, suggesting the use of pANCA to define specific disease subgroups. Our recent finding that the UC-associated pANCA reactive antigen was localized within the nuclear domain prompted an examination of whether DNase treatment of neutrophils would alter antigenic recognition by the pANCA of UC, PSC, and type 1 AIH. While loss of antigenic recognition after DNase digestion of neutrophils was a dominant feature of the UC-associated pANCA, the majority of PSC and type 1 AIH pANCA recognized cytoplasmic constituents. These results further support the feasibility of defining and/or distinguishing disease subgroups based on the characterization of respective pANCA.

Nuclear localization of the antigen detected by ulcerative colitis-associated perinuclear antineutrophil cytoplasmic antibodies

Antineutrophil cytoplasmic antibodies (ANCAs) identified in the serum of 50 to 80% of ulcerative colitis (UC) patients yield a perinuclear staining pattern (pANCA) with alcohol-fixed neutrophils. The ANCAs of UC are distinguishable from those described for Wegener's granulomatosis and other vasculitidies. These various non-UC ANCAs recognize neutrophil granule constituents, but the antigenic moiety specific for the UC pANCA remains unknown. Although the perinuclear nature of some ANCA reactions is an artifact of the alcohol fixation of neutrophils, which causes cytoplasmic granules to redistribute around the nucleus, the UC pANCA reaction has been found not to be similarly affected. We postulated a nuclear localization for the UC-associated pANCA antigen and used both confocal laser microscopy and immunoelectron microscopy to examine the neutrophil reaction of UC-associated pANCA-containing sera. Confocal microscopy revealed a nuclear reaction for 88% (22/25) of the sera with 72% (18/25) showing the reaction localizing to the inner side of the nuclear (membrane) periphery. Immunoelectron microscopy showed that the UC-associated pANCA reaction localized primarily over chromatin concentrated toward the nuclear periphery, although the sera did not recognize double-stranded DNA. These results confirm the nuclear localization of the UC-associated pANCA antigen.

Perinuclear anti-neutrophil cytoplasmic antibodies are spontaneously produced by mucosal B cells of ulcerative colitis patients

Approximately 60% of sera from ulcerative colitis (UC) patients contains Igs reactive with neutrophil components, raising the question of the origin of these anti-neutrophil cytoplasmic Abs (ANCA). Our assertion that ANCA is a marker for a mucosal disease-related immune response predicts the existence of ANCA producing B cell clones in the lamina propria lymphocyte (LPL) fraction of UC patients. This hypothesis was tested by examining 12-day culture supernatants of LPL ANCA expression. LPL were isolated from surgically removed mucosa from patients with UC, Crohn's disease (CD), and diverticulitis. Normal mucosa was obtained from accident victims or normal margins of colon cancer resections. Supernatants were assayed by a fixed neutrophil ELISA. The ANCA staining pattern of supernatants expressing ANCA, as determined by ELISA, was assessed by indirect immunofluorescent staining of alcohol-fixed neutrophils. ANCA was found in 70% of culture supernatants from UC LPL fractions. In contrast, only approximately 11% of supernatants from CD and diverticulitis/normal (noninflammatory bowel disease (IBD)) LPL displayed ANCA binding. A perinuclear (pANCA) staining pattern was obtained with 70% of ANCA-expressing UC LPL supernatants, whereas ANCA-expressing CD and non-IBD LPL supernatants displayed a cytoplasmic reaction. PBL and mesenteric lymph node lymphocytes lacked spontaneous pANCA production, and pANCA production from PBL was not inducible. These findings indicate the existence of pANCA-producing B cell clones in mucosal lesions of UC patients and support our hypothesis that pANCA production is a consequence of a mucosal immune response specific to UC.

Perinuclear anti-neutrophil cytoplasmic antibodies are spontaneously produced by mucosal B cells of ulcerative colitis patients

Approximately 60% of sera from ulcerative colitis (UC) patients contains Igs reactive with neutrophil components, raising the question of the origin of these anti-neutrophil cytoplasmic Abs (ANCA). Our assertion that ANCA is a marker for a mucosal disease-related immune response predicts the existence of ANCA producing B cell clones in the lamina propria lymphocyte (LPL) fraction of UC patients. This hypothesis was tested by examining 12-day culture supernatants of LPL ANCA expression. LPL were isolated from surgically removed mucosa from patients with UC, Crohn's disease (CD), and diverticulitis. Normal mucosa was obtained from accident victims or normal margins of colon cancer resections. Supernatants were assayed by a fixed neutrophil ELISA. The ANCA staining pattern of supernatants expressing ANCA, as determined by ELISA, was assessed by indirect immunofluorescent staining of alcohol-fixed neutrophils. ANCA was found in 70% of culture supernatants from UC LPL fractions. In contrast, only approximately 11% of supernatants from CD and diverticulitis/normal (noninflammatory bowel disease (IBD)) LPL displayed ANCA binding. A perinuclear (pANCA) staining pattern was obtained with 70% of ANCA-expressing UC LPL supernatants, whereas ANCA-expressing CD and non-IBD LPL supernatants displayed a cytoplasmic reaction. PBL and mesenteric lymph node lymphocytes lacked spontaneous pANCA production, and pANCA production from PBL was not inducible. These findings indicate the existence of pANCA-producing B cell clones in mucosal lesions of UC patients and support our hypothesis that pANCA production is a consequence of a mucosal immune response specific to UC.

Investigation of lung tumour induction in BALB/cJ mice following paternal X-irradiation

Evidence of an enhanced incidence of lung tumours (benign adenomas and adenocarcinomas) was sought in the BALB/cJ mouse following paternal germ cell X-irradiation. In a series of replicate studies spanning approximately 1 year, males were exposed to single, acute X-ray doses of 0, 250 and 500 cGy. In each of the 2 consecutive weeks immediately thereafter they were placed with two females to generate progeny that were derived from irradiated post-meiotic cells (spermatozoa to late spermatids). These animals were then examined at 8 or 12 months for lung tumours. While the proportion of fertile females and mean litter size was affected by the radiation, showing a dose-dependent, dominant lethal response, and while cases of mutant offspring were detected, the paternal radiation did not affect lung tumour incidence in the offspring. The incidence did not vary significantly between germ cell stages irradiated (week of mating), sex of offspring, or radiation dose. However, significant differences between lung tumour incidence (mostly representing benign adenomas) were found between different replicates, these being high at the start of the study, declining and then rising to yet higher levels at its close. The finding that lung tumour incidence in BALB/cJ mice is not affected by paternal germ cell irradiation does not accord with Nomura's reports using other strains of mice. This, in turn, weakens biological support for a causal association between the raised incidence of childhood leukaemia and non-Hodgkin lymphoma near Sellafield and the father's recorded radiation exposure during employment by the nuclear industry.

Molecular genetic characterization of six recessive viable alleles of the mouse agouti locus

The agouti locus on mouse chromosome 2 encodes a secreted cysteine-rich protein of 131 amino acids that acts as a molecular switch to instruct the melanocyte to make either yellow pigment (phaeomelanin) or black pigment (eumelanin). Mutations that up-regulate agouti expression are dominant to those causing decreased expression and result in yellow coat color. Other associated effects are obesity, diabetes, and increased susceptibility to tumors. To try to define important functional domains of the agouti protein, we have analyzed the molecular defects present in a series of recessive viable agouti mutations. In total, six alleles (amJ, au, ada, a16H, a18H, ae) were examined at both the RNA and DNA level. Two of the alleles, a16H and ae, result from mutations in the agouti coding region. Four alleles (amJ, au, a18H, and ada) appear to represent regulatory mutations that down-regulate agouti expression. Interestingly, one of these mutations, a18H, also appears to cause an immunological defect in the homozygous condition. This immunological defect is somewhat analogous to that observed in motheaten (me) mutant mice. Short and long-range restriction enzyme analyses of homozygous a18H DNA are consistent with the hypothesis that a18H results from a paracentric inversion where one end of the inversion maps in the 5' regulatory region of agouti and the other end in or near a gene that is required for normal immunological function. Cloning the breakpoints of this putative inversion should allow us to identify the gene that confers this interesting immunological disorder.

Diuretic therapy for hypertension and the risk of primary cardiac arrest

BACKGROUND

The results of trials of the primary prevention of coronary heart disease have suggested that treating hypertension with high doses of thiazide diuretic drugs might increase the risk of sudden death from cardiac causes. In contrast, treatment with low doses of thiazide reduces the risk of coronary heart disease.

METHODS

To examine the association between thiazide treatment for hypertension and the occurrence of primary cardiac arrest, we conducted a population-based case-control study among enrollees of a health maintenance organization. The case patients were 114 persons with hypertension who had a primary cardiac arrest from 1977 through 1990. The control patients were a stratified random sample of 535 persons with hypertension. The patients' treatment was assessed with the use of a computerized pharmacy data base. Records of their ambulatory care were reviewed to determine other clinical characteristics.

RESULTS

The risk of primary cardiac arrest among patients receiving combined thiazide and potassium-sparing diuretic therapy was lower than that among patients treated with a thiazide without potassium-sparing therapy (odds ratio, 0.3; 95 percent confidence interval, 0.1 to 0.7). As compared with low-dose thiazide therapy (25 mg daily), moderate-dose therapy (50 mg daily) was associated with a moderate increase in risk (odds ratio, 1.7; 95 percent confidence interval, 0.7 to 4.5), and high-dose therapy (100 mg daily) was associated with a larger increase in risk (odds ratio, 3.6; 95 percent confidence interval, 1.2 to 10.8) (P value for trend, 0.02). The addition of a potassium-sparing drug to low-dose thiazide therapy was associated with a reduced risk of cardiac arrest (odds ratio, 0.4; 95 percent confidence interval, 0.1 to 1.5).

CONCLUSIONS

Both the dose of thiazide drugs and the addition of potassium-sparing drugs influence the risk of primary cardiac arrest. These results may explain the differences in the effect of antihypertensive therapy on mortality from coronary heart disease in previous clinical trials.

Pseudomyxoma peritonei

Pseudomyxoma peritonei results from implantation of malignant tumors or irritation from ruptured benign cysts. This disease is traditionally characterized by accumulation of mucinous ascites, relatively long survival period and absence of extraperitoneal metastases. Disease progression is difficult to predict because of the spectrum of underlying pathologic entities. Four unusual instances of pseudomyxoma peritonei are presented. An instance of the neoplasm confined to the splenic parenchyma suggests potential for hematogenous dissemination. The tumor can be limited to and extend along the retroperitoneum. Retained rectal tissue after proctocolectomy may be a possible origin of disease. Enterobronchial fistula formation is a serious long term complication. Aggressive surgical approach with resection of the bulk of disease offers the optimal palliation and prognosis.

Analysis of childhood pedestrian deaths in New Mexico, 1986-1990

STUDY OBJECTIVE

To determine if the mechanism of fatal childhood pedestrian injuries correlated with location, injury pattern, and age of the pedestrian and to determine ethnic differences in fatality rates.

DESIGN

Retrospective review of state medical investigator reports and autopsies from 1986 to 1990. Logistic regression and chi 2 were used to test for statistically significant differences between the groups in our data set.

TYPE OF PARTICIPANTS

New Mexican children, 0 to 14 years old fatally injured by moving vehicles.

RESULTS

Sixty-four children died for an overall fatality rate of 3.8 (per 100,000). Native American children and children younger than 5 years experienced the highest fatality rates. Children younger than 5 years were more likely to be crushed under the wheels of a slow-moving vehicle in both a nontraffic and a traffic location, whereas older children were found more often to have died from injuries from a high-speed impact event in a traffic location (P < .001). Leg fractures (P = .001) and spinal fractures (P = .02) occurred more frequently in impact than crush injuries.

CONCLUSION

Young children are at risk for a crush injury in both the traffic and nontraffic environment.

Socioeconomic status and prediction of ventricular fibrillation survival

OBJECTIVES

The association between socioeconomic status and cardiac arrest is less well known than some other associations with cardiac arrest. We used property tax assessments as a measure of socioeconomic status in a study of victims of out-of-hospital cardiac arrest found in ventricular fibrillation.

METHODS

We studied patients attended by the Seattle Fire Department's emergency medical services system between May 1986 and August 1988. During the period studied, 356 episodes met the study criteria; 114 (32%) of these patients survived without major neurologic deficit. Residential property tax assessments were available for 253 of the patients.

RESULTS

After adjustments were made for age, witnessed collapse, bystander-initiated cardiopulmonary resuscitation, time from call to paramedic arrival, activity, location of collapse, and chronic morbidity, an association of survival with greater assessed value per living unit was observed. An increase of $50,000 in value per unit was associated with a 1.6-fold increase in survival rate.

CONCLUSIONS

Not only are persons in the lower socioeconomic strata at greater risk for cardiac mortality, but they are also less likely to survive an episode of out-of-hospital cardiac arrest.

Comparison of CT, low-field-strength MR imaging, and high-field-strength MR imaging. Work in progress

To assess objectively the sensitivity and specificity of low-field-strength (0.064 T) magnetic resonance (MR) imaging, a prospective blind study of 280 examinations was performed to compare low-field-strength MR imaging with computed tomography (CT) and with high-field-strength (1.5-T) MR imaging of the cranium. The sensitivity (defined as the true-positive rate) with high-field MR imaging was superior to that with low-field MR imaging and CT in helping detect overall abnormalities. Sensitivities were generally similar over a broad range of specific cranial central nervous system diseases. Low-field and high-field MR imaging were equivalent in the blind diagnoses of neoplasms and white matter disease, whereas low-field MR and CT were equivalent in the blind diagnoses of contusion, subdural and epidural hematoma, sinus disease, normality, and abnormality. The specificities with low-field MR imaging and CT were substantially better than those with high-field MR imaging.

Age-related prognosis after acute myocardial infarction (the Multicenter Diltiazem Postinfarction Trial)

The basis for the excess mortality with age after acute myocardial infarction (AMI) is not clear, nor is it known whether the mode of death is altered with age. Age-related factors predictive of mortality and age-related mechanisms of the 333 deaths were examined in 2,466 patients who were enrolled in a placebo-controlled trial to determine the effect of diltiazem on mortality and reinfarction after AMI. There were 3 age groups with increasing mortality rates: ages 25 to 49 (n = 499), 50 to 64 (n = 1,228) and 65 to 75 years (n = 739). There was a significant age-related increase in the proportion of patients with baseline risk factors. These baseline characteristics did not differ by treatment (placebo vs diltiazem). However, multivariate survivorship analysis still identified age as an independent risk factor for cardiac death. The proportion of arrhythmic and myocardial failure deaths did not differ by treatment or age group.

Low incidence of glomerulosclerosis in normal kidneys

Forty normal kidneys were selected from a series of 146 renal samples obtained at forensic autopsies of American Indians and whites. Glomeruli were counted and the percentage of globally sclerosed, obsolescent glomeruli was calculated for each case. The mean for sclerotic glomeruli was less than 3% in any age group younger than 56 years. This finding is in agreement with the results of similar studies, but substantially lower than the figures quoted in textbooks. Analysis of the combination of our data with studies performed by other authors shows that the 90th percentile of glomerular sclerosis can be calculated for any age by subtracting 10 from half the patient's age. No ethnic- or sex-related differences were seen in any age group.

Comparison of statistical methods for the analysis of limiting dilution assays

This study reports the results of a critical comparison of five statistical methods for estimating the density of viable cells in a limiting dilution assay (LDA). Artificial data were generated using Monte Carlo simulation. The performance of each statistical method was examined with respect to the accuracy of its estimator and, most importantly, the accuracy of its associated estimated standard error (SE). The regression method was found to perform at a level that is unacceptable for scientific research, due primarily to gross underestimation of the SE. The maximum likelihood method exhibited the best overall performance. A corrected version of Taswell's weighted-mean method, which provides the best performance among all noniterative methods examined, is also presented.

Power analysis of statistical methods for comparing treatment differences from limiting dilution assays

Six different statistical methods for comparing limiting dilution assays were evaluated, using both real data and a power analysis of simulated data. Simulated data consisted of a series of 12 dilutions for two treatment groups with 24 cultures per dilution and 1,000 independent replications of each experiment. Data within each replication were generated by Monte Carlo simulation, based on a probability model of the experiment. Analyses of the simulated data revealed that the type I error rates for the six methods differed substantially, with only likelihood ratio and Taswell's weighted mean methods approximating the nominal 5% significance level. Of the six methods, likelihood ratio and Taswell's minimum Chi-square exhibited the best power (least probability of type II errors). Taswell's weighted mean test yielded acceptable type I and type II error rates, whereas the regression method was judged unacceptable for scientific work.

Enhanced exercise noradrenaline concentrations during propranolol treatment: a limiting factor in cardiac beta-adrenoceptor blockade

Treatment with beta-adrenoceptor blocking drugs may result in augmented plasma concentrations of noradrenaline during exercise. The effect of propranolol on exercise heart rate and its relationship to plasma concentrations of propranolol and noradrenaline were examined in 10 hospitalized volunteers following treatment with propranolol, in doses of 80 mg and 320 mg daily. Responses to submaximal treadmill exercise during propranolol treatment and following discontinuation of the higher dose were compared to pre-drug and post drug placebo values. Exercise noradrenaline was increased by 67% over baseline values by treatment with the 320 mg daily dose of propranolol; this increment was present at 4 h and returned to baseline by 16 h after drug administration. Augmentation of exercise noradrenaline was correlated with plasma propranolol concentrations; the threshold concentration for this effect was 10-fold higher than the threshold for reduction in exercise heart rate. The effect of propranolol on heart rate was blunted in relation to the augmentation of exercise noradrenaline (P less than 0.001). These relationships suggest that, in patients taking high doses of propranolol, drug induced augmentation of plasma levels of noradrenaline during exercise may have physiologic importance. Enhanced effects on adrenergic receptors could have clinical relevance in certain groups of patients.

An attachable silver-impregnated cuff for prevention of infection with central venous catheters: a prospective randomized multicenter trial

PURPOSE

Percutaneously inserted central venous catheters are widely used. Catheter-related bacteremia or fungemia is the most frequent serious complication of these catheters. In an attempt to reduce the frequency of such infections, a subcutaneous cuff constructed of a biodegradable collagen matrix impregnated with bactericidal silver was developed. Our goal was to assess, in a multicenter clinical trial, the effectiveness of this cuff in preventing catheter-related infection.

MATERIALS AND METHODS

Central venous catheters needed for fluid or drug therapy, hemodynamic monitoring, or hyperalimentation in patients in three centers were randomly assigned to be inserted with or without the cuff. Patients and catheters in the two groups were comparable in terms of risk factors predisposing to infection, including colonization of skin about the insertion site.

RESULTS

The results with 234 catheters inserted into a new site showed that catheters inserted with the cuff were threefold less likely to be colonized on removal (more than 15 colony-forming units) than were control catheters (28.9 percent versus 9.1 percent, p = 0.002) and were nearly fourfold less likely to produce bacteremia (3.7 percent versus 1.0 percent). Adverse effects from the cuff were not seen. The cuff did not confer protection, however against infection with catheters inserted over a guidewire into old sites. Most of the catheter-related infections identified in this study, including four of the six bacteremias, appear to have been caused by microorganisms colonizing skin about the insertion site, affirming the pathogenetic basis for benefit seen with the cuff in this clinical trial; two may have derived from contamination of the catheter hub.

CONCLUSION

This novel, silver-impregnated, attachable cuff can substantially reduce the incidence of catheter-related infection with most percutaneously inserted central venous catheters, can extend the time catheters can be left in place safely, and can prove cost-beneficial.

Suppression, stress, and accommodation of transplanted islets of Langerhans

Successful intrasplenic islet autotransplantation in dogs requires an islet cell mass considerably greater than what might be expected based on studies of subtotal pancreatectomy. Grafts of marginal function ultimately fail, suggesting severe limitations in the capacity of an islet graft to adapt. Accommodation was tested in established intrasplenic grafts by either chronically stressing the graft with mild carbohydrate intolerance induced by exogenous corticosteroids or chronically suppressing the graft with exogenous insulin. After these manipulations, insulin output into the portal vein in response to intravenous (i.v.) glucose was measured and compared with that of normal dogs and dogs receiving islet autografts with no further treatment with either steroids or insulin. Transplanted islets tolerated the two manipulations well in that neither exogenous steroid nor insulin led to failure of the graft as a consequence of either stress or protracted diminished demand. The major determinant of successful islet grafting is the endocrine competence of the initial graft. If that competence is provided at the outset, the graft can adapt to a considerable range of demand for insulin secretion.

The metabolic response of intrasplenic islet autografts

Islet tissue was prepared by collagenase ductal perfusion in mongrel dogs and transplanted to the spleen as autografts following total pancreatectomy. The graft was introduced into the spleen by reflux through tributaries of the splenic vein. Total insulin output by the in situ islet cell mass and by the heterotopically transplanted islet cell mass was studied by measuring insulin in the portal vein prior to pancreatectomy and two weeks after grafting. Basal insulin as well as the insulin output in response to 0.5 gram per kilogram of intravenous glucose were measured. Normoglycemia was achieved immediately in all grafted dogs. The results of intravenous glucose tolerance testing suggested only a mild degree of carbohydrate intolerance in the grafted dogs. Insulin output in 60 minutes after glucose stimilation was similar for in situ and grafted islet cells. The results of glucose clamp studies did not reveal any significant change in the insulin sensitivity of grafted as opposed to normal dogs. Islets of Langerhans may be harvested by the ductal perfusion method to yield a completely adequate islet cell mass for grafting purposes in the canine model following total pancreatectomy.

Computer reconstruction of serial sections

A computer graphics system is described which reconstructs three-dimensional images from serial sectional data. Microscopic sectional tracings are first digitized and coded with a microcomputer (APPLE II-Plus). The data are transferred to a main frame facility for reconstruction and the final result is displayed on a high-resolution color monitor (Hewlett-Packard 9845C). Depth cueing of the image is enhanced by edge ribboning and area filling. The system is very simple to operate and yet flexible enough to allow selective portions of the tissue sample to be reconstructed and displayed in various orientations.

Islet recovery in chronic pancreatitis

Chronic pancreatitis ablates a large majority of the acinar tissue which otherwise is a troublesome contaminant in preparing islet cells from higher mammals. Chronic pancreatitis was induced by dividing all pancreatic attachments to the duodenum, including major and minor ducts, in six dogs. After 10 weeks, biopsy of the pancreas showed marked acinar cell atrophy and fibrosis with preservation and even proliferation of islet cells. Intravenous glucose tolerance testing revealed only a minor decrease in K value from 3.4 +/- 1.0 to 2.1 +/- 0.4 during 10 weeks. All dogs then underwent total pancreatectomy and islet autotransplantation. The pancreas was dispersed to a cell suspension by perfusing the pancreatic ducts with collagenase until tissue integrity failed. The digested tissue was then chopped, dissociated by shaking, and filtered. The average cell yield from the pancreas was 7.6 X 10(7) cells of which greater than 95% were islet cells. Acid alcohol-extracted insulin values suggested an average 7% recovery of insulin content and essentially complete elimination of amylase content was demonstrated.

Word imagery modalities and learning in the deaf and hearing

The study explored the modality specific hypothesis of imagery concreteness. Twenty-four male and female deaf and hearing adolescents learned lists of paired associates that were either high visual and low auditory imagery words or the obverse. It was predicted that the deaf group would perform as well as the hearing group with pairs of high visual imagery, but worse with materials of high auditory imagery. The results failed to demonstrate the expected interaction. However, indirect support for the hypothesis was provided by a third order interaction trend analysis which suggested that the deaf group experienced difficulty in learning the high auditory imagery word pairs.