A Predictive Model to Identify Complicated Clostridiodes difficile Infection

Background

Clostridioides difficile infection (CDI) is a leading cause of health care-associated infection and may result in organ dysfunction, colectomy, and death. Published risk scores to predict severe complications from CDI demonstrate poor performance upon external validation. We hypothesized that building and validating a model using geographically and temporally distinct cohorts would more accurately predict risk for complications from CDI.

Methods

We conducted a multicenter retrospective cohort study of adults diagnosed with CDI. After randomly partitioning the data into training and validation sets, we developed and compared 3 machine learning algorithms (lasso regression, random forest, stacked ensemble) with 10-fold cross-validation to predict disease-related complications (intensive care unit admission, colectomy, or death attributable to CDI) within 30 days of diagnosis. Model performance was assessed using the area under the receiver operating curve (AUC).

Results

A total of 3646 patients with CDI were included, of whom 217 (6%) had complications. All 3 models performed well (AUC, 0.88-0.89). Variables of importance were similar across models, including albumin, bicarbonate, change in creatinine, non-CDI-related intensive care unit admission, and concomitant non-CDI antibiotics. Sensitivity analyses indicated that model performance was robust even when varying derivation cohort inclusion and CDI testing approach. However, race was an important modifier, with models showing worse performance in non-White patients.

Conclusions

Using a large heterogeneous population of patients, we developed and validated a prediction model that estimates risk for complications from CDI with good accuracy. Future studies should aim to reduce the disparity in model accuracy between White and non-White patients and to improve performance overall.

External Validation and Comparison of Clostridioides difficile Severity Scoring Systems

BACKGROUND

Many models have been developed to predict severe outcomes from Clostridioides difficile infection. These models are usually developed at a single institution and largely are not externally validated. This aim of this study was to validate previously published risk scores in a multicenter cohort of patients with CDI.

METHODS

Retrospective study on four separate inpatient cohorts with CDI from three distinct sites: The Universities of Michigan (2010-2012 and 2016), Chicago (2012), and Wisconsin (2012). The primary composite outcome was admission to an intensive care unit, colectomy, and/or death attributed to CDI within 30 days of positive testing. Both within each cohort and combined across all cohorts, published CDI severity scores were assessed and compared to each other and the IDSA guideline definitions of severe and fulminant CDI.

RESULTS

A total of 3,646 patients were included for analysis. Including the two IDSA guideline definitions, fourteen scores were assessed. Performance of scores varied within each cohort and in the combined set (mean area under the receiver operator characteristic curve(AUC 0.61, range 0.53-0.66). Only half of the scores had performance at or better than IDSA severe and fulminant definitions (AUCs 0.64 and 0.63, respectively). Most of the scoring systems had more false than true positives in the combined set (mean: 81.5%, range:0-91.5%).

CONCLUSIONS

No published CDI severity score showed stable, good predictive ability for adverse outcomes across multiple cohorts/institutions or in a combined multicenter cohort.

The Clinical Impact of Implementation of a Multidisciplinary Endocarditis Team

BACKGROUND

Infectious endocarditis is associated with substantial in-hospital mortality of 15-20%. Effective management requires coordination between multiple medical and surgical subspecialties which can often lead to disjointed care. Previous European studies have identified multidisciplinary endocarditis teams as a tool for reducing endocarditis mortality.

METHODS

The multidisciplinary endocarditis Team was formed in May 2018. The group developed an evidence-based algorithm for management of endocarditis that was used to provide recommendations for hospitalized patients over a 1-year period. Mortality outcomes were then retroactively assessed and compared to a historical control utilizing propensity matching.

RESULTS

Between June 2018 and June 2019 the team provided guideline-based recommendations on 56 patients with Duke Criteria definite endocarditis and at least 1 AHA indication for surgery. The historical control included 68 patients with definite endocarditis and surgical indications admitted between July 1^st, 2014 to June 30^th, 2015. In-hospital mortality decreased significantly from 29.4% in 2014-2015 to 7.1% in 2018-2019 (p<0.0001). There was a non-significant increase in the rate of surgical intervention after implementation of the team (41.2% vs 55.4%; p=0.12). Propensity score matching demonstrated similar results.

CONCLUSIONS

Implementation of a multidisciplinary endocarditis team was associated with a significant 1-year decrease in all-cause in-hospital mortality for patients with definite endocarditis and surgical indications, in the presence of notable differences between the two studied cohorts. In conjunction with previous studies demonstrating their effectiveness, this data supports that widespread adoption of endocarditis teams in North America could improve outcomes for this patient population.

713. The Clinical Impact of Implementation of a Multidisciplinary Endocarditis Team

Background

Infectious endocarditis is associated with substantial in-patient mortality of 15-20%. Effective management requires coordination between multiple medical and surgical subspecialties which can often lead to disjointed care. Previous European studies have identified multidisciplinary endocarditis teams as a tool for reducing endocarditis mortality.

Methods

The University of Michigan Multidisciplinary Endocarditis Team was formed on May 3^rd, 2018. The group developed an evidence-based algorithm for management of endocarditis that was used to provide recommendations for hospitalized patients over a 1-year period. Mortality outcomes were then retroactively assessed and compared to a historical control that was identified using an internal research tool.

Figure 1

Table 1

Results

Between June 14^th, 2018 and June 13^th, 2019 the team provided guideline-based recommendations on 56 patients with Duke Criteria definite endocarditis and at least 1 American Heart Association indication for surgery. The historical control included 68 patients with definite endocarditis and surgical indications admitted between July 1^st, 2014 to June 30^th, 2015. In-hospital mortality decreased significantly from 29.4% in 2014-2015 to 7.1% in 2018-2019 (p< 0.0001). There was a non-significant increase in the rate of surgical intervention after implementation of the team (41.2% vs 55.4%; p=0.12).

Table 2

Table 3

Table 4

Conclusion

Implementation of a multidisciplinary endocarditis team was associated with a significant 1-year decrease in all-cause in-hospital mortality for patients with definite endocarditis and surgical indications. In conjunction with previous studies demonstrating their effectiveness, this data supports that widespread adoption of endocarditis teams in North America has the potential to improve outcomes for this patient population.

Table 5

Disclosures

All Authors: No reported disclosures

Physician perceptions of a multidisciplinary endocarditis team

Infectious endocarditis is a highly morbid infection that requires coordination of care across medical and surgical specialties, often through the use of a multidisciplinary team model. Multiple studies have demonstrated that such conferences can improve clinical outcomes. However, little is known about physicians' impressions of these groups. We surveyed 126 (response rate of 30%) internal medicine, infectious diseases, cardiology, and cardiac surgery providers 1 year after the implementation of an endocarditis team at the University of Michigan. Ninety-eight percent of physicians felt that the endocarditis team improved communication between specialties. Additionally, over 85% of respondents agreed that the group influenced diagnostic evaluation, reduced management errors, increased access to surgery, and decreased in-hospital mortality for endocarditis patients. These results suggest that multidisciplinary endocarditis teams are valued by physicians as a tool to improve patient care and serve an important role in increasing communication between providers.

A Resident-Led Initiative to Increase Documentation of Surrogate Decision Makers for Hospitalized Patients

BACKGROUND

Identification of surrogate decision makers (SDMs) is an important part of advance care planning for hospitalized patients. Despite its importance, the best methods for engaging residents to sustainably improve SDM documentation have not been identified.

OBJECTIVE

We implemented a hospital-wide quality improvement initiative to increase identification and documentation of SDMs in the electronic health record (EHR) for hospitalized patients, utilizing a Housestaff Quality and Safety Council (HQSC).

METHODS

EHR documentation of SDMs for all adult patients admitted to a tertiary academic hospital, excluding psychiatry, were tracked and grouped by specialty in a weekly run chart during the intervention period (July 2015 through April 2016). This also continued postintervention. Interventions included educational outreach for residents, monthly plan-do-study-act cycles based on performance feedback, and a financial incentive of a one-time payment of 0.75% of a resident's salary put into the retirement account of each resident, contingent on meeting an SDM documentation target. Comparisons were made using statistical process control and chi-square tests.

RESULTS

At baseline, SDMs were documented for 11.1% of hospitalized adults. The intervention period included 9146 eligible admissions. Hospital-wide SDM documentation increased significantly and peaked near the financial incentive deadline at 48% (196 of 407 admissions, P < 001). Postintervention, hospital-wide SDM documentation declined to 30% (134 of 446 admissions, P < .001), but remained stable.

CONCLUSIONS

This resident-led intervention sustainably increased documentation of SDMs, despite a decline from peak rates after the financial incentive period and notable differences in performance patterns by specialty admitting service.

Assessment of a cytomegalovirus serology dual-testing strategy in hematopoietic stem cell transplant recipients

BACKGROUND

Accurate determination of recipient cytomegalovirus (CMV) serostatus before allogeneic hematopoietic stem cell transplantation (HSCT) is critical, as it is the most important predictor of post-transplant CMV infection and remains associated with non-relapse mortality. The purpose of this study was to assess a recipient dual-testing strategy before HSCT.

METHODS

CMV serologic testing was performed before allogeneic HSCT using 2 different assays: reference laboratory (RL) and American Red Cross (ARC). In all cases, blood samples were obtained for RL testing either before ARC testing (median 130 days before HSCT [range 12-2594]) or at the same time (median 25 days before HSCT [range 8-129]). The results of serologic testing were correlated with CMV viremia post HSCT.

RESULTS

Of 287 recipients evaluated, 76 (26.5%) had discordant results, of which 74 (97.4%) tested RL-/ARC+. Ten had RL and ARC testing performed on simultaneously obtained samples, 3 of which (30%) were discordant (3 [100%] RL-/ARC+). Acute myeloid leukemia and receipt of blood product transfusion in the interval between testing were associated with RL-/ARC+ discordance. Correlation with viremia after HSCT suggested that RL-/ARC+ discordance was caused by detection of anti-CMV immunoglobulin transferred in transfused blood products and reduced specificity of the ARC assay.

CONCLUSION

CMV-seronegative hematopoietic stem cell transplant recipients may be misclassified as seropositive if testing is performed after receipt of blood products or when using assays optimized for sensitivity at the expense of specificity. This misclassification may negatively affect post-HSCT outcomes for individual patients and studies that rely on accurate CMV serology reporting.

Allelopathic effects of litter on the growth and colonization of mycorrhizal fungi

In laboratory studies, water-soluble extracts of the litter of four shrub and three conifer species had variable effects on the growth of four species of ectomycorrhizal fungi. In general, low concentrations (parts per thousand) stimulated fungal growth; while, high concentrations (parts per hundred and parts per ten) either stimulated growth, inhibited growth, or had no effect, depending on both fungal and litter species. In greenhouse studies, litter applied to the surface of a sand-soil mixture reduced the formation ofRhizopogon sp. on Douglas-fir seedlings. Allelochemicals in the litter may inhibit seedling growth and suppress fungai growth and root colonization in the field, thus explaining the failures of reforestation by conifer species in disturbed sites.

Self-organizing systems across scales

Over the past few years, ecologists have increasingly recognized the existence of strong self-reinforcing (or self-organizing) interactions within systems at a variety of scales. Positive feedback within food chains has been reported from terrestrial and aquatic ecosystems. Accumulating evidence supports the existence within communities of cooperative guilds - tit-for-tat relationships based on diffuse mutualisms and favored by environmental unpredictability. At the landscape level, both real world experience and models indicate that processes such as hydrology and the propagation of disturbance can be strongly self-reinforcing (i.e. the landscape structure supports the process, and vice versa). Hence the picture emerges of a hierarchy of self-organizing systems that span food chains, communities and landscapes/regions.

Optical map of the genotype A1 WB C6 Giardia lamblia genome isolate

The Giardia lamblia genome consists of 12 Mb divided among 5 chromosomes ranging in size from approximately 1 to 4 Mb. The assembled contigs of the genotype A1 isolate, WB, were previously mapped along the 5 chromosomes on the basis of hybridization of plasmid clones representing the contigs to chromosomes separated by PFGE. In the current report, we have generated an MluI optical map of the WB genome to improve the accuracy of the physical map. This has allowed us to correct several assembly errors and to better define the extent of the subtelomeric regions that are not included in the genome assembly.

Effects of skyrin, a receptor-selective glucagon antagonist, in rat and human hepatocytes

Peptidic glucagon antagonists have been shown to lower blood glucose levels in diabetic models (1-3), but attempts to identify small molecular weight glucagon receptor-binding antagonists have met with little success. Skyrin, a fungal bisanthroquinone, exhibits functional glucagon antagonism by uncoupling the glucagon receptor from adenylate cyclase activation in rat liver membranes (1). We have examined the effects of skyrin on cells transfected with the human glucagon receptor and on isolated rat and human hepatocytes. The skyrin used was isolated from Talaromyces wortmanni American Type Culture Collection 10517. In rat hepatocytes, skyrin (30 micromol/l) inhibited glucagon-stimulated cAMP production (53%) and glucose output (IC50 56 micromol/l). There was no detectable effect on epinephrine or glucagon-like peptide 1 (GLP-1) stimulation of these parameters, which demonstrates skyrin's selective activity. Skyrin was also evaluated in primary cultures of human hepatocytes. Unlike cell lines, which are largely unresponsive to glucagon, primary human hepatocytes exhibited glucagon-dependent cAMP production for 14 days in culture (EC50 10 nmol/l). Skyrin (10 micromol/l) markedly reduced glucagon-stimulated cAMP production (55%) and glycogenolysis (27%) in human hepatocytes. The inhibition of glucagon stimulation was a specific property displayed by skyrin and oxyskyrin but not shared by other bisanthroquinones. Skyrin is the first small molecular weight nonpeptidic agent demonstrated to interfere with the coupling of glucagon to adenylate cyclase independent of binding to the glucagon receptor. The data presented in this study indicate that functional uncoupling of the human glucagon receptor from cAMP production results in metabolic effects that could reduce hepatocyte glucose production and hence alleviate diabetic hyperglycemia.

Selamectin: a novel broad-spectrum endectocide for dogs and cats

Selamectin, 25-cyclohexyl-25-de(1-methylpropyl)-5-deoxy-22, 23-dihydro-5-(hydroxyimino)-avermectin B1 monosaccharide, is a novel endectocide with a unique combination of efficacy and safety in dogs and cats following both oral and topical administration. The compound is active against fleas and ticks, intestinal hookworms and ascarids, and immature heartworms. Also it is well tolerated at higher dosages than 22,23-dihydroavermectin B1a (DHAVM) or milbemycin oxime in Collies, which is a breed known to exhibit idiosyncratic sensitivity to avermectins.

Avermectins and flea control: structure-activity relationships and the selection of selamectin for development as an endectocide for companion animals

Evaluation of a wide range of avermectin derivatives for flea activity in an in vitro feeding screen using the cat flea, Ctenocephalides felis, revealed a narrow structure-activity relationship (SAR) with activity surprisingly associated with monosaccharides and especially their C-5-oximes. We discovered commercially exploitable flea activity in a single compound, selamectin 33, which also possessed the necessary antiparasitic spectrum and margin of safety for development as a broad-spectrum companion animal endectocide.

In vitro study of the effects of Nd:YAG laser probe parameters on bovine oral soft tissue excision

BACKGROUND AND OBJECTIVES

Lasers are now used for intraoral, soft tissue procedures. The effects of Nd:YAG probes on cutting efficiency and temperature rise were evaluated in vitro.

STUDY DESIGN/MATERIALS AND METHODS

Three hundred twenty-micron 400-microns, 500-microns, and 600-microns probes were used to ablate bovine gingiva, mucosa, and tongue at various power and frequency settings. Thermocouples positioned under the subjacent cortical bone measured temperature rise. Tissue samples were evaluated histologically.

RESULTS

Mean pooled temperature rise was 1 degree C at 3 W and 1.4 degrees C at 5 W. Excision width ranged from 0..63 mm to 0.79 mm at tested settings, cutting depths from 0.19 mm to 0.49 mm, lateral and deep coagulation from 0.27 mm to 0.62 mm.

CONCLUSION

Temperature rise in bone was related to increased power. Cutting efficiency of laser probes was not significantly improved by increased power. Probes of 320 to 500 microns provided efficient cutting at 3 W and 5 W, thus reducing the potential for unacceptable temperature rise in bone.

Malignant supratentorial ganglioglioma (ganglion cell-giant cell glioblastoma): a case report and review of the literature

BACKGROUND

From both epidemiologic and pathologic viewpoints, gangliogliomas exhibiting components of giant cell glioblastomas are extraordinary neoplasms. We report herein the case of a 6-year-old girl who presented initially with a World Health Organization grade IV anaplastic ganglioglioma (a mixed ganglion cell tumor-giant cell glioblastoma). Despite aggressive management, the patient died of disease in a relatively short period.

METHODS

Formalin-fixed, paraffin-embedded tissue blocks were sectioned at 5 microm for histochemical and immunohistochemical analyses. Hematoxylin-eosin-stained sections and immunohistochemically stained sections from the primary and secondary resections were reviewed. Reactivity for glial fibrillary acidic protein, neurofilament protein, synaptophysin, and Ki67 nuclear antigen was evaluated.

RESULTS

Histologically, 2 distinct cell populations were noted on both the primary and secondary resections. The primary resection revealed a neoplasm having a predominant glial component consistent with a glioblastoma. Interspersed were dysmorphic ganglion cells supporting a diagnosis of ganglioglioma. The second resection (following therapy) demonstrated a much more prominent dysmorphic ganglion cell component and a subdued glial component.

CONCLUSION

Although immunohistochemical analysis clearly distinguished the 2 tumor cell populations, the identification of Nissl substance in neurons proved to be equally helpful. Although other cases of grade III gangliogliomas and rare cases of grade IV gangliogliomas have been reported, the present case is exceptional in that, to our knowledge, it is the only report of a patient who presented initially with a composite grade IV ganglioglioma and who was clinically followed up to the time of death. This case allows direct comparison between the histologic findings in a giant cell glioblastoma and a ganglioglioma and documents the aggressive biologic behavior of this complex neoplasm.

Gingival microcirculation response to tooth brushing measured by laser Doppler flowmetry

This study quantified changes in blood flow following tooth brushing, using laser Doppler flowmetry (LDF). Twenty subjects had polysiloxane stents fabricated with openings to permit placement of the LDF probe on the mesial papillae of 6 teeth. Probing depth, plaque index, and gingival index were recorded and subjects instructed in brushing. LDF initially recorded a 30 second baseline blood flow. The stent was removed and subjects brushed the site for either 3 or 10 seconds. The stent was repositioned and recordings again taken, followed by a control reading. The process was repeated 4 weeks later. Correlations between baseline and control readings were 0.585 (P < 0.001) at the first visit, and 0.654 (P < 0.001) at the return visit. The mean control blood flow was 156.4 perfusion units. The 3 and 10 second brushing increased the mean value 22.6 units and 21.2 units respectively (both P < 0.001). Tooth brushing for both 3 and 10 seconds significantly increased gingival blood flow in the papillary gingiva of healthy individuals.

Aspects of quality of dental hygiene care in supervised and unsupervised practices

OBJECTIVE

The purpose of this study was to assess aspects of the quality of care provided by dental hygienists in a California demonstration project in which hygienists treated patients independent of dentists' supervision.

METHODS

The structure and process of care were evaluated in nine independent practices using site visits and reviews of 25 records at each practice. The findings were compared to evaluations of six general dentist practices reviewed for a government agency and insurance company during the same time period. Patient satisfaction was assessed by a questionnaire.

RESULTS

The structural aspects of the unsupervised hygienist practices were generally acceptable and surpassed the dentist practices in most areas, including infection control. For process, the hygienist practices had high percentages of acceptable care and were significantly better than the dentist practices in several areas, including follow-up to medical findings, updating the medical history at recall, and documenting the evaluation of the periodontal status and soft tissues. Ninety-eight percent of patients expressed satisfaction with their care in hygienist practices.

CONCLUSION

Under the circumstances of the demonstration project and the methods used to assess the quality of care, the study showed that independent dental hygienist practice did not increase the risk to the health and safety of the public.

Characteristics of patients seeking care from independent dental hygienist practices

OBJECTIVES

This study determined demographic characteristics, satisfaction with care, and likelihood of follow-up dentist visits for patients seen in office-based, independent, dental hygienist practices.

METHODS

New patients were surveyed after their initial visits to independent hygienist practices to assess their demographic characteristics and satisfaction with care at both the beginning of practice operations and 18 months after the start of these practices. Follow-up surveys were sent to patients 12 and 24 months after their initial visits to the independently practicing dental hygienists to determine if patients had visited a dentist.

RESULTS

Most respondents were white, female, had attended some college, and reported high family incomes. Ninety-eight percent of respondents were satisfied with their dental hygiene care. Follow-up questionnaires revealed that over 80 percent of respondents visited the dentist within 12 months of receiving dental hygiene care in independent settings. This level of follow-up care with dentists was found both for respondents who reported having a regular dentist at their initial visits with the hygienists and for those who reported not having a regular dentist.

CONCLUSIONS

Independent practice by dental hygienists provided access to dental hygiene care and encouraged visits to the dentist.

Practice characteristics of dental hygienists operating independently of dentist supervision

PURPOSE

This paper presents business characteristics of ten experimental independent dental hygiene practices operating in California between 1987 and 1990. Sixteen dental hygienists participated in the experiment, the Health Manpower Pilot Project 139 (HMPP 139). HMPP 139 dental hygienists wanted to work independently in traditional office-based settings, institutional settings, and other arrangements. They worked in group and solo practices, on a full- or part-time basis.

METHODS

Data were collected from the HMPP 139 practices on services provided, patient visits, fees charged, referrals to dentists, acceptance of Medicaid patients, and services to organizational clients. Data collection methods varied, depending on the question addressed. Surveys of dentists' offices provided data on fees and Medicaid policies for comparison with the independent dental hygiene practices.

RESULTS

All experimental practices attracted new patients for each quarter in operation. These practices mostly provided prophylaxis treatments; however, a wide variety of services was provided. Fees charged in HMPP 139 office-based practices were less than comparable fees charged in dentists' offices. At least one-third of patients in the HMPP 139 office-based settings received a referral to or an opinion about a dentist from the dental hygienist. HMPP 139 practices were more available to Medicaid patients than were California dentists offices. Each experimental independent practice provided care to at least one client in a nontraditional setting.

CONCLUSIONS

The HMPP 139 practices consistently attracted new patients. This suggests independent practice for dental hygienists may be a viable and flexible alternative if the practices can stabilize total patients at a sufficiently high level. An independent practice alternative might increase access to care, contain fees, and direct the flow of patients to dentists. Further study is needed to test these findings.

Ranitidine therapy for esophagitis in children with developmental disabilities

Esophagitis is common in children with cerebral palsy. Because histamine2-receptor antagonists such as ranitidine have not been uniformly effective, we treated disabled children with esophagitis with greater than usual doses. Endoscopy and pH monitoring were used to monitor dose and response to treatment. A dose of 9.3 +/- 0.9 mg/kg/day did not improve visual or microscopic esophagitis after 3 months. A dose of 14.8 +/- 3.9 mg/kg/day resulted in only slight microscopic improvement, but symptoms were improved. There was no correlation between esophageal reflux index at enrollment and either severity of esophagitis or response to treatment. Elevation of gastric pH by ranitidine was infrequent. These results affirm that pH monitoring does not reliably identify disabled children with reflux esophagitis nor does ranitidine reliably heal this disorder.

Aggressive natural killer cell lymphoma of the small intestine

We report a case of aggressive non-Hodgkin's lymphoma of the small cell type arising in the small intestine and having a natural killer cell phenotype. Immunophenotyping of frozen tissue sections revealed a lack of reactivity with the pan-T-cell markers CD3 and CD5, and no reaction with B-cell markers. Positive staining was obtained with antibodies to CD2, CD7, and CD56. Molecular studies were negative for clonal T gamma, T beta and immunoglobulin heavy-chain gene rearrangements. Natural-killer-cell-associated cytotoxin was demonstrated by positive staining with an antibody to perforin, a protein present in the granules of large granular lymphocytes. Despite its indolent histologic appearance, the aggressive nature of this neoplasm was suggested by the expression of the activation markers CD38 and CD71, and the nuclear proliferation marker Ki67, and confirmed clinically by its rapid recurrence with extensive involvement of the pelvic organs, resistance to chemotherapy, and the short survival of the patient. Distinct from many Asian cases, Epstein-Barr virus genome was not detectable in the tumor. This case emphasizes the importance of recognizing non-Hodgkin's lymphomas with a natural killer cell phenotype as a distinct entity, both biologically and clinically.

Comparison of a conventional probe with electronic and manual pressure-regulated probes

We compared the accuracy, consistency, time, comfort, and cost of probing with a conventional hand probe (CP) with 3-mm banded markings, a manual pressure-regulated probe (MP), and two electronic probes (IP and FP). Twenty (20) examiners used all four probes on a test block to determine accuracy; measurements compared favorably to the reference block. Two calibrated examiners probed the Ramfjord teeth of 10 periodontal patients on maintenance regimens, six sites per tooth (n = 708), with all four probes; measurements were repeated after one week. Wilcoxon signed-rank test showed the CP measured more deeply (P < 0.0001) than MP, FP, and IP with mean differences of 0.40, 0.67, and 0.58 respectively. MP measured more deeply (P < 0.001) than FP and IP, with mean differences of 0.27 and 0.18 mm. There was no difference between FP and IP. Time (min:sec) required by one examiner to perform full mouth probing on six subjects (minimum of 26 teeth each) was CP = 3:59; MP = 4:18; FP = 6:16; and IP = 7:23. Subjects rated FP and IP as slightly more uncomfortable than CP or MP. Cost per 1,000 uses was computed based on available data. The IP and FP took longer to perform and cost more per procedure than did the CP and MP. Spearman rank-order correlation revealed that only probe depths measured by CP and MP were well correlated (rs = 0.67). Although some statistically significant differences were found between probes, no differences were considered to be of clinical significance when probing periodontally healthy or maintenance patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic monoarticular arthritis and acute pericardial tamponade in a child with Crohn's disease

We describe a 7-year-old child who developed right knee arthritis unresponsive to nonsteroidal anti-inflammatory drug therapy. Additional rheumatologic disorders including pleuropericardial effusion with tamponade supervened before the recognition of Crohn's disease involving the colon. Suppression of all sites of inflammation resulted from corticosteroid therapy. Aspects of diagnosis and treatment of these extraintestinal components of inflammatory bowel disease are discussed.

Giant cell fibroblastoma with dermatofibrosarcoma protuberans-like transformation

A giant cell fibroblastoma (GCF) presented in the subcutis of the breast in a 13-month-old girl which recurred 6 years later as a dermal and subcutaneous neoplasm whose patterns were in part GCF and spindle cells with a storiform configuration resembling dermatofibrosarcoma protuberans (DFSP). The issue remains unsettled as to whether GCF is the juvenile variant of DFSP, but an argument about this relationship is supported circumstantially by a case such as ours.

Evaluating the efficacy of a new flossing aid

The purpose of this clinical trial was to compare the efficacy of a new flossing aid (Flosser) with finger flossing on preventing plaque and gingival inflammation. 35 adults who did not use dental floss routinely were assigned randomly to one of 2 treatment groups (Flosser or finger flossing) in a 2-period, single-blind crossover study. After prophylaxis, subjects were instructed to use the flossing aid or finger floss 1 x per day and to continue brushing for 30 days. Gingival inflammation (GI & BPI) and plaque (PI) were assessed prior to the prophylaxis and at 30 days. After a 30 day "washout" period, subjects were again reassessed for gingival inflammation and plaque, given a prophylaxis, assigned the opposite treatment (2nd treatment period) that they received the first treatment period, and assessed (GI, BPI & PI) after 30 days. Comparing the mean difference of the 30-day buccal interproximal scores between the treatment groups (flossing aid scores minus finger flossing scores) showed that the mean differences with 95% CI were: -0.013 +/- 0.067 [GI], -0.017 +/- 0.044 [BP] and 0.019 +/- 0.014 [PI]. No statistically significant differences from zero (0.05 alpha) were observed using the t-test. There was a high level of compliance (90%) with the prescribed regiment, and subjects preferred (56%) the flossing aid slightly over finger flossing. Even though there were no statistically or clinically significant differences in gingivitis and plaque scores between the 2 flossing groups, the positive inclination for the flossing aid makes it a desirable addition to the armamentarium of preventive dentistry.

C-13 beta-acyloxymilbemycins, a new family of macrolides. Discovery, structural determination and biological properties

A family of novel milbemycins possessing C-13 beta-acyloxy substitution was produced by Streptomyces hygroscopicus ATCC 53718. These compounds were detected by HPLC diode array analysis and possess anthelmintic and ectoparasiticidal activity. The origin of the oxygen atom at C-13 is discussed.

Diffuse intermediate lymphocytic lymphoma. A clinicopathologic study and comparison with small lymphocytic lymphoma and diffuse small cleaved cell lymphoma

Controversy has recently arisen as to whether diffuse intermediate lymphocytic lymphoma (ILL) should be considered a low-grade or an intermediate-grade non-Hodgkin's lymphoma for clinical purposes. Therefore, the authors performed a clinicopathologic study to determine the biologic course of diffuse ILL (40 cases) and compared it with small lymphocytic lymphoma (SLL; 51 cases) and diffuse small cleaved cell lymphoma (DSCCL; 14 cases). They found that patients with diffuse ILL having pseudofollicular proliferation centers (PC) had a significantly longer median survival (84 months) than those without PC (46.5 months; P = 0.03). The median survival of patients with SLL was 72 months, whereas those with DSCCL had a median survival of only 18 months. Based on these findings, the authors conclude that diffuse ILL with PC should be included in the low-grade category of SLL for clinical purposes, whereas diffuse ILL without PC (true diffuse ILL) should be considered an intermediate-grade non-Hodgkin's lymphoma. True diffuse ILL is similar to centrocytic lymphoma in the Kiel classification and should be accorded a similar status in a modified Working Formulation.

Occurrence of periodontitis in an urban adolescent population

The presence of periodontitis in 307 black, Hispanic, and Asian students age 12 to 15 years was evaluated by calibrated examiners in a Los Angeles inner city junior high school. The periodontal status of maxillary and mandibular incisors and permanent first molars was evaluated using the Plaque Index, probing depth, attachment loss, bleeding on probing, tooth mobility, presence of calculus, and caries. Thirty-nine (12.7%) of 307 students had 5 mm or deeper probing depths and associated attachment loss of at least 2 mm and were considered to have periodontitis (PD). The PD group had significantly more bleeding, calculus, and missing teeth than the non-PD group, but both groups had moderate to severe plaque accumulation. The distribution and severity of disease increased with age. Deeper probing depths were associated with the molar teeth and six (15.4%) of the 39 subjects in the PD group had furcation involvement. Clinical screening alone was not sufficient to determine if the periodontitis seen was localized juvenile periodontitis; however, the program detected a high occurrence of periodontitis in this population group.

Ectomycorrhizal mediation of competition between coniferous tree species

To test the effect of ectomycorrhizal fungi (EMF) on interactions between host plants, Pseudotsuga menziesii (Mirb.) Franco and Pinus ponderosa Dougl. ex. Laws., seedlings were grown in replacement series in pasteurized soil with (a) no EMF added, (A) two EMF species added - Rhizopogon vinicolor Smith (specific to Douglas-fir) and R. ochraceorubens Smith (specific to pine), and (c) tour EMF species added - the two Rhizopogon species plus two host generalists, Laccaria laccata (Scop, ex Fr.) Bk. & Br, and Hebeloma crustuliniforme (Bull.) Quel. A replacement series in unpasteurized forest soil also was included. Seedlings without added EMF were colonized by the greenhouse contaminant, Thelephora terrestris. Without added EMF (but with T. terrestris), the tree species mutually inhibited one another, producing Relative Yield Totals significantly < 1; with EMF added, mutual inhibition disappeared. With four EMF species added, Pseudotsuga menziesii seedlings were significantly larger in mixture than in monoculture, with no corresponding decrease in the size of Pinus ponderoso seedlings; this was due solely to seedlings with L. laccata, which apparently enhanced nitrogen (N) and phosphorus (P) uptake by Pseudotsuga menziesii at the expense of luxury consumption by Pinus ponderosa. Graphical analysis suggested that better growth of Pseudotosuga menziesii in mixture with EMF added was related to improved P nitrogen. Both N and P nutrition of Pinus ponderosa was better in mixture with two than no EMF species added; there was no clear nutrient effect with four EMF species added. Results indicate that EMF can reduce competition between plant species and perhaps increase overall community P uptake. However, patterns were specific to both EMF and tree species and were quite different in unpasteurized soils. Hence generalizations about the effects of EMF on plant-plant interactions must be made cautiously.

Indomethacin and 7,12-dimethylbenz(a)anthracene-induced carcinogenesis in the hamster buccal pouch

Indomethacin was not observed to produce any significant effect upon hamster buccal pouch carcinogenesis. No statistically significant difference in delayed hypersensitivity response to dinitrochlorobenzene was found between indomethacin-treated, tumor-bearing and control groups.

WINTER FIXATION OF NITROGEN IN SCOTCH BROOM (CYTISUS SCOPARIUS L.)

The retention of green lateral branches by Scotch Broom allows nitrogen fixation to continue during mild winters. Tolerance of low soil temperatures is suggested to be a major factor contributing to the occurrence of winter nitrogen fixation.