263 INFORMING INTERVENTION DESIGN IN COGNITIVELY IMPAIRED POPULATIONS: LESSONS LEARNED FROM THE OPTIMIZE DEPRESCRIBING INTERVENTION

Background

Polypharmacy is common in older adults with cognitive impairment and multiple chronic conditions increasing their risks of adverse drug events, hospitalization, further cognitive decline and death and leading to higher health care costs. Deprescribing, the process of reducing or stopping potentially inappropriate medications may improve outcomes. The OPTIMIZE trial examined whether educating and activating patients, family and clinicians about deprescribing reduces number of medications for older adults with cognitive impairment and multiple chronic conditions. Acceptability and challenges of intervention delivery in this vulnerable population are not well understood.

Methods

We explored mechanisms of intervention effectiveness through post hoc qualitative interviews and surveys with 15 patients, 7 family caregivers, and 28 clinicians. We assessed accessibility and delivery of materials as well as the ability of the materials to facilitate conversations and influence decisions around deprescribing.

Results

Acceptance of the intervention was affected by contextual factors including cognition and prior knowledge of deprescribing. Positive effects of the intervention included patients scheduling specific appointments to discuss deprescribing and providers being prompted to consider deprescribing. Recollection of intervention materials by patients was inconsistent but highest shortly after intervention delivery. Short clinic visit times remained the largest clinician barrier to deprescribing.

Conclusion

Our work identifies key learnings in intervention roll out which can guide future scaling of our intervention and other pragmatic deprescribing intervention studies in patients with cognitive impairment. We highlight the critical roles of both timing and repetition in intervention delivery to cognitively impaired populations as well as the barrier to deprescribing posed by short clinic consultation time. Our success in activating deprescribing conversations in this population highlights the need to incentivize medical professionals and health systems to incorporate deprescribing into routine clinical practice and expand proven interventions to other vulnerable populations.

The OPTIMIZE patient- and family-centered, primary care-based deprescribing intervention for older adults with dementia or mild cognitive impairment and multiple chronic conditions: study protocol for a pragmatic cluster randomized controlled trial

Background

Most individuals with dementia or mild cognitive impairment (MCI) have multiple chronic conditions (MCC). The combination leads to multiple medications and complex medication regimens and is associated with increased risk for significant treatment burden, adverse drug events, cognitive changes, hospitalization, and mortality. Optimizing medications through deprescribing (the process of reducing or stopping the use of inappropriate medications or medications unlikely to be beneficial) may improve outcomes for MCC patients with dementia or MCI.

Methods

With input from patients, family members, and clinicians, we developed and piloted a patient-centered, pragmatic intervention (OPTIMIZE) to educate and activate patients, family members, and primary care clinicians about deprescribing as part of optimal medication management for older adults with dementia or MCI and MCC. The clinic-based intervention targets patients on 5 or more medications, their family members, and their primary care clinicians using a pragmatic, cluster-randomized design at Kaiser Permanente Colorado. The intervention has two components: a patient/ family component focused on education and activation about the potential value of deprescribing, and a clinician component focused on increasing clinician awareness about options and processes for deprescribing. Primary outcomes are total number of chronic medications and total number of potentially inappropriate medications (PIMs). We estimate that approximately 2400 patients across 9 clinics will receive the intervention. A comparable number of patients from 9 other clinics will serve as wait-list controls. We have > 80% power to detect an average decrease of − 0.70 (< 1 medication). Secondary outcomes include the number of PIM starts, dose reductions for selected PIMs (benzodiazepines, opiates, and antipsychotics), rates of adverse drug events (falls, hemorrhagic events, and hypoglycemic events), ability to perform activities of daily living, and skilled nursing facility, hospital, and emergency department admissions.

Discussion

The OPTIMIZE trial will examine whether a primary care-based, patient- and family-centered intervention educating patients, family members, and clinicians about deprescribing reduces numbers of chronic medications and PIMs for older adults with dementia or MCI and MCC.

Trial registration

NCT03984396. Registered on 13 June 2019

Quality of care assessment for people with multimorbidity

Multimorbidity, the simultaneous presence of multiple health conditions in an individual, is an increasingly common phenomenon globally. The systematic assessment of the quality of care delivered to people with multimorbidity will be key to informing the organization of services for meeting their complex needs. Yet, current assessments tend to focus on single conditions and do not capture the complex processes that are required for providing care for people with multimorbidity. We conducted a scoping review on quality of care and multimorbidity in selected databases in June 2018 and identified 87 documents as eligible for review, predominantly original research and reviews from North America, Europe and Australasia and mostly frequently related to primary care settings. We synthesized data qualitatively in terms of perceived challenges, evidence and proposed metrics. Findings reveal that the association between quality of care and multimorbidity is complex and depends on the conditions involved (quality appears to be higher for those with concordant conditions, and lower in the presence of discordant conditions) and the approach used for measuring quality (quality appears to be higher in people with multimorbidity when measured using condition/drug-specific process or intermediate outcome indicators, and worse when using patient-centred reports of experiences of care). People with discordant multimorbidity may be disadvantaged by current approaches to quality assessment, particularly when they are linked to financial incentives. A better understanding of models of care that best meet the needs of this group is needed for developing appropriate quality assessment frameworks. Capturing patient preferences and values and incorporate patients' voices in the form of patient-reported experiences and outcomes of care will be critical towards the achievement of high-performing health systems that are responsive to the needs of people with multimorbidity.

Photochemical Aging of α-pinene and β-pinene Secondary Organic Aerosol formed from Nitrate Radical Oxidation

The nitrate radical (NO3) is the dominant nighttime oxidant in most urban and rural environments and reacts rapidly with biogenic volatile organic compounds to form secondary organic aerosol (SOA) and organic nitrates (ON). Here, we study the formation of SOA and ON from the NO3 oxidation of two monoterpenes (α-pinene and β-pinene) and investigate how they evolve during photochemical aging. High SOA mass loadings are produced in the NO3+β-pinene reaction, during which we detected 41 highly oxygenated gas- and particle-phase ON possessing 4 to 9 oxygen atoms. The fraction of particle-phase ON in the β-pinene SOA remains fairly constant during photochemical aging. In contrast to the NO3+β-pinene reaction, low SOA mass loadings are produced during the NO3+α-pinene reaction, during which only 5 highly oxygenated gas- and particle-phase ON are detected. The majority of the particle-phase ON evaporates from the α-pinene SOA during photochemical aging, thus exhibiting a drastically different behavior from that of β-pinene SOA. Our results indicate that nighttime ON formed by NO3+monoterpene chemistry can serve as either permanent or temporary NOx sinks depending on the monoterpene precursor.

Modeling the Current and Future Roles of Particulate Organic Nitrates in the Southeastern United States

Organic nitrates are an important aerosol constituent in locations where biogenic hydrocarbon emissions mix with anthropogenic NOx sources. While regional and global chemical transport models may include a representation of organic aerosol from monoterpene reactions with nitrate radicals (the primary source of particle-phase organic nitrates in the Southeast United States), secondary organic aerosol (SOA) models can underestimate yields. Furthermore, SOA parametrizations do not explicitly take into account organic nitrate compounds produced in the gas phase. In this work, we developed a coupled gas and aerosol system to describe the formation and subsequent aerosol-phase partitioning of organic nitrates from isoprene and monoterpenes with a focus on the Southeast United States. The concentrations of organic aerosol and gas-phase organic nitrates were improved when particulate organic nitrates were assumed to undergo rapid (τ = 3 h) pseudohydrolysis resulting in nitric acid and nonvolatile secondary organic aerosol. In addition, up to 60% of less oxidized-oxygenated organic aerosol (LO-OOA) could be accounted for via organic nitrate mediated chemistry during the Southern Oxidants and Aerosol Study (SOAS). A 25% reduction in nitrogen oxide (NO + NO2) emissions was predicted to cause a 9% reduction in organic aerosol for June 2013 SOAS conditions at Centreville, Alabama.

Transinhibition and voltage-gating in a fungal nitrate transporter

We have applied enzyme kinetic analysis to electrophysiological steady-state data of Zhou et al. (Zhou, J.J., Trueman, L.J., Boorer, K.J., Theodoulou, F.L., Forde, B.G., Miller, A.J. 2000. A high-affinity fungal nitrate carrier with two transport mechanisms. J. Biol. Chem. 275:39894-9) and to new current-voltage-time records from Xenopus oocytes with functionally expressed NrtA (crnA) 2H+-NO3- symporter from Emericella (Aspergillus) nidulans. Zhou et al. stressed two Michaelis-Menten (MM) mechanisms to mediate the observed nitrate-induced currents, I(NO3-). We show that a single straightforward reaction cycle describes the data well, pointing out that during exposure to external substrate, S = (2H+ + NO3-)o, the product concentration inside, [P] = [H+]i(2) x [NO3-]i, may rise substantially near the plasma membrane, violating the condition [P] << [S] for MM kinetics. Here, [P] and its changes during experimentation are treated explicitly. K(1/2) approximately 20 microM for I(NO3-) at pHo from Zhou et al. is confirmed. According to our analysis, NrtA operates between about 0.2 and 0.6 of the electrical distance in the membrane (outside 0, inside 1). In absence of thermodynamic gradients, the predominant orientation of the binding site(s) is probably inwards. The activity of the enzyme is sensitive to the transmembrane voltage, V, with an apparent gating charge of +1.0 +/- 0.5 for inactivation, and transition probabilities of 0.3-1.3 s(-1) at V = 0. This gating mode impedes loss of cellular NO3- during depolarization.

The forehead flap for nasal reconstruction

CONTEXT

Reconstruction of extensive nasal defects often represents a significant challenge owing to several unique qualities of the nose, such as complex topography, mobile free margins, and multiple nasal subunits. Furthermore, loss of internal nasal lining and/or structural skeletal support may be present following removal of extensive skin cancers.

OBJECTIVE

To describe our experience with the use of forehead flap reconstruction for extensive nasal defects.

DESIGN

Retrospective case series.

SETTING

Academic health care hospital system.

PATIENTS/INTERVENTION

One hundred forty-seven patients with extensive nasal defects repaired with a forehead flap.

MAIN OUTCOME MEASURES

The functional and aesthetic results were assessed. The characteristics of defects repaired with the forehead flap and the need for lining and/or cartilage were examined.

RESULTS

The forehead flap was used to repair 147 nasal defects after Mohs excision of nonmelanoma skin cancer. Full-thickness skin was lost in all cases, structural skeletal support in 68 cases (46%), and internal mucosal lining in 45 cases (31%). Our experience and surgical technique using the forehead flap are described.

CONCLUSIONS

The forehead flap represents one of the best methods for repair of extensive nasal defects. Near-normal functional and cosmetic results can be achieved.

Electrophysiology of the marine diatom Coscinodiscus wailesii IV: types of non-linear current-voltage-time relationships recorded with single saw-tooth voltage-clamp experiments

Electrophysiological states of the marine diatom Coscinodiscus wailesii are known to change spontaneously in the temporal range of seconds. In order to assess the genuine current-voltage-time relationships of individual states in less than a second, voltage-clamp experiments have been carried out using single sweeps of saw-tooth shaped command voltages. This method is introduced with model calculations. Plotting the results in current-voltage coordinates provides convenient access to several electrophysiological entities, such as absence of drift (smoothly closed IV loops), membrane capacitance (by I jump at sign reversal of dV/dt), and ohmic conductances (in linear regions of the current-voltage relationship), as well as equilibrium voltage (internal intersection of capacitance-corrected, 8-shaped tracings) and coarse gating kinetics (rise or fall of capacitance-corrected I at sign reversal of dV/dt) of a voltage-sensitive ion conductance. From electrophysiological measurements with double-barreled glass-microelectrodes on C. wailesii, several distinct types of current-voltage loops are presented. Most of the data, including recordings from electrical excitation, can be interpreted as temporal relaxations of voltage-sensitive conductances for K(+) and Cl(-). A more detailed analysis of the effect of tetraethylammonium (TEA(+)) shows that 10 and 20 mM TEA(+) inhibit the K(+) conductance in C. wailesii only by up to about 20% but predominantly via a K(+) outward rectifier.

Three types of membrane excitations in the marine diatom Coscinodiscus wailesii

Three types of electrical excitation have been investigated in the marine diatom Coscinodiscus wailesii. I: Depolarization-triggered, transient Cl(-) conductance, G(Cl)(t), followed by a transient, voltage-gated K(+) conductance, G(K), with an active state a and two inactive states i(1) and i(2) in series (a-i(1)-i(2)). II: Similar G(Cl)(t) as in Type-I but triggered by hyperpolarization; a subsequent increase of G(K) in this type is indicated but not analyzed in detail. III: Hyperpolarization-induced transient of a voltage-gated activity of an electrogenic pump (i(2)-a-i(2)), followed by G(Cl)(t) as in Type-II excitations. Type-III with pump gating is novel as such. G(Cl)(t) in all types seems to reflect the mechanism of InsP(-)(3) and Ca(2+)-mediated G(Cl)(t) in the action potential in Chara (Biskup et al., 1999). The nonlinear current-voltage-time relationships of Type-I and Type-III excitations have been recorded under voltage-clamp using single saw-tooth command voltages (voltage range: -200 to +50 mV, typical slope: +/-1 Vs(-1)). Fits of the corresponding models to the experimental data provided numerical values of the model parameters. The statistical significance of these solutions is investigated. We suggest that the original function of electrical excitability of biological membranes is related to osmoregulation which has persisted through evolution in plants, whereas the familiar and osmotically neutral action potentials in animals have evolved later towards the novel function of rapid transmission of information over long distances.

Species and genotypic diversities and similarities of pathogenic yeasts colonizing women

We examined the patterns of strain relatedness among pathogenic yeasts from within and among groups of women to determine whether there were significant associations between genotype and host condition or body site. A total of 80 yeast strains were isolated, identified, and genotyped from 49 female volunteers, who were placed in three groups: (i) 19 women with AIDS, (ii) 11 pregnant women without human immunodeficiency virus (HIV) infection, and (iii) 19 women who were neither pregnant nor infected with HIV. Seven yeast species were recovered, including 59 isolates of Candida albicans, 9 isolates of Candida parapsilosis, 5 isolates of Candida krusei, 3 isolates of Candida glabrata, 2 isolates of Saccharomyces cerevisiae, and 1 isolate each of Candida tropicalis and Candida lusitaniae. Seventy unique genotypes were identified by PCR fingerprinting with the M13 core sequence and by random amplified polymorphic DNA analysis. Of the nine shared genotypes, isolates from three different hosts were of one genotype and pairs of strains from different body sites of the same host shared each of the other eight genotypes. Genetic similarities among groups of strains were calculated and compared. We found no significant difference in the patterns of relatedness of strains from the three body sites (oral cavity, vagina, and rectum), regardless of host conditions. The yeast microflora of all three host groups had similar species and genotypic diversities. Furthermore, a single host can be colonized with multiple species or multiple genotypes of the same species at the same or different body sites, indicating dynamic processes of yeast colonization on women.

Personal performance profiles: a useful adjunct to quality assurance in cervical cytology

In our laboratory, which processes approximately 40,000 smears annually, the reporting patterns of each individual primary screener have been continuously monitored over a 6-year period. The detection rates for minor abnormalities (borderline/mild dyskaryosis) and major abnormalities (moderate dyskaryosis and worse) are published quarterly in the laboratory. Individual continuous monitoring rapidly identifies screeners with low detection rates. It is a useful adjunct to existing methods of quality assurance; rescreening can be more appropriately directed to smears reported by screeners with low detection rates. It also identifies training needs and may be used to assess the value of update courses for each screener. It is a faster method of identifying poor performance than rapid review of all smears. The reporting rate of inadequate smears is also calculated and published on a quarterly basis. This promotes a degree of uniformity within the laboratory in the rate at which smears are reported as inadequate, and also reduces the inadequate rate.

External loops at the C terminus of Erwinia chrysanthemi pectate lyase C are required for species-specific secretion through the out type II pathway

The type II secretion system (main terminal branch of the general secretion pathway) is used by diverse gram-negative bacteria to secrete extracellular proteins. Proteins secreted by this pathway are synthesized with an N-terminal signal peptide which is removed upon translocation across the inner membrane, but the signals which target the mature proteins for secretion across the outer membrane are unknown. The plant pathogens Erwinia chrysanthemi and Erwinia carotovora secrete several isozymes of pectate lyase (Pel) by the out-encoded type II pathway. However, these two bacteria cannot secrete Pels encoded by heterologously expressed pel genes from the other species, suggesting the existence of species-specific secretion signals within these proteins. The functional cluster of E. chrysanthemi out genes carried on cosmid pCPP2006 enables Escherichia coli to secrete E. chrysanthemi, but not E. carotovora, Pels. We exploited the high sequence similarity between E. chrysanthemi PelC and E. carotovora Pel1 to construct 15 hybrid proteins in which different regions of PelC were replaced with homologous sequences from Pell. The differential secretion of these hybrid proteins by E. coli(pCPP2006) revealed M118 to D175 and V215 to C329 as regions required for species-specific secretion of PelC. We propose that the primary targeting signal is contained within the external loops formed by G274 to C329 but is dependent on residues in M118 to D170 and V215 to G274 for proper positioning.

Impaired vocal cord mobility in the setting of acute suppurative thyroiditis

BACKGROUND

Acute suppurative thyroiditis is an increasingly rare entity, accounting for less than 0.1% of thyroid surgery. This is the first report in the literature of acute thyroiditis causing a unilateral reversible vocal cord paralysis.

METHODS

A 41-year-old woman was initially seen with a unilateral vocal cord paralysis resulting from acute suppurative thyroiditis.

RESULTS

The vocal cord paralysis resolved following surgical drainage of the thyroid abscess and treatment with intravenous antibiotics.

CONCLUSIONS

We present this case to emphasize the need for a complete and thorough head and neck exam including preoperative documentation of vocal cord mobility.

Differential effect of site-directed mutations in pelC on pectate lyase activity, plant tissue maceration, and elicitor activity

Oligonucleotide site-directed mutations were introduced into the pelC gene of Erwinia chrysanthemi EC16 that directed single or double amino acid changes affecting disulfide linkages, calcium binding, catalysis, and protein folding. Subsequent characterization of the purified PelC mutant proteins demonstrated that pectinolytic function involves amino acids located near the calcium binding site rather than those surrounding an invariant vWiDH sequence. Wild-type PelC and the tested mutant proteins generally macerated plant tissue in proportion to their specific pectinolytic activity in vitro. However, some mutants gave higher maceration activity in plant tissue and elicited greater production of the phytoalexin, glyceollin, in soybean cotyledons than predicted by their in vitro pectinolytic activity. Most notable in this regard were three different mutations at lysine 172 with greatly reduced pectinolytic activity but as much elicitor activity as the wild-type protein. PelE macerated plant tissue 10 times more efficiently than PelC, as observed previously, but surprisingly showed equal activity in the elicitor assay. The results indicate that factors other than pectinolytic activity per se are involved in plant tissue maceration and elicitor activity.

The immunology of thyroid cancer

This article reviews the immunologic aspects of thyroid cancer, including thyroid-specific effector elements on thyroid cancer, and discusses the potential antigens, unique molecular markers, and transcription factors that could serve as targets for immunotherapy. The potential role of this type of treatment for thyroid cancer is examined also.

Clinical utility of In-111 leukocyte imaging in Crohn's disease

Thirty six patients with Crohn's disease were studied with In-111 leukocyte imaging. There was a correlation of the presence of activity on early (4 hour) imaging (r = 0.516, P < 0.001) and on delayed 18-24 hour) imaging (r = 0.457, P < 0.003). In the total group of 36 patients, the results of imaging were useful in the immediate management of 13 patients (36.1%). These included four patients (11.1%) who refused to undergo colonoscopic examination and nine patients (25%), six of whom had previous intestinal resection.

Characterization of the Pseudomonas aeruginosa alginate lyase gene (algL): cloning, sequencing, and expression in Escherichia coli

Mucoid strains of Pseudomonas aeruginosa produce a viscous exopolysaccharide called alginate and also express alginate lyase activity which can degrade this polymer. By transposon mutagenesis and gene replacement techniques, the algL gene encoding a P. aeruginosa alginate lyase enzyme was found to reside between algG and algA within the alginate biosynthetic gene cluster at 35 min on the P. aeruginosa chromosome. DNA sequencing data for algL predicted a protein product of ca. 41 kDa, including a 27-amino-acid signal sequence, which would be consistent with its possible localization in the periplasmic space. Expression of the algL gene in Escherichia coli cells resulted in the expression of alginate lyase activity and the appearance of a new protein of ca. 39 kDa detected on sodium dodecyl sulfate-polyacrylamide gels. In mucoid P. aeruginosa strains, expression of algL was regulated by AlgB, which also controls expression of other genes within the alginate gene cluster. Since alginate lyase activity is associated with the ability to produce and secrete alginate polymers, alginate lyase may play a role in alginate production.

Diagnostic value of Tc-99m MAA radionuclide venography of lower extremity: as a simultaneous procedure of ventilation-perfusion scan for pulmonary embolism

A total of 336 cases received a ventilation-perfusion(V/Q) scan for the detection of pulmonary embolism (PE). Among these, 155 cases simultaneously underwent a successful radionuclide venography study (RNV) of the lower limbs using Tc-99m macro-aggregated albumin (MAA). Concomitant pulmonary arteriography (PA) was performed in 120 cases. Fifty-four of these 120 cases successfully completed the RNV scan. There was a statistical significance in the V/Q scan for the detection of PE as confirmed by the PA (p less than 0.0001). The positive predictive value (PPV) of the RNV for PE was 75% (3/4). The negative predictive value (NPV) was 48% (24/50). The sensitivity and specificity were 10% (3/29) and 96% (24/25) for the 54 patients who had both the RNV scan and PA. For the 155 patients who had simultaneous V/Q and RNV scans, there was no statistically significant correlation between these two scans. The PPV, NPV, specificity and sensitivity were 42%(8/19), 75%(103/136), 90%(103/114) and 20%(8/41), respectively. Despite the low sensitivity and no significance of positive RNV for diagnosis of PE, RNV is still recommendable because it is a simple, non-invasive, simultaneous procedure during perfusion lung scan and has high specificity.

A rapid method for standardization of the gated radionuclide left ventricular ejection fraction

Radionuclide ventriculography has become the standard method for serially evaluating left ventricular ejection fraction (EF). The "gold standard" for evaluating EF is the contrast ventriculogram, which uses mathematical models to arrive at the volumes used to calculate EF. These models are subject to possible error. This paper reports the standardization of volume measurements of a digital angiographic camera system using a series of cardiac phantoms and the correlation of measurement of the EF of a series of patients whose EF was determined by digital angiography and radionuclide ventriculography.

Osteoporosis: diagnosis by plain chest film versus dual photon bone densitometry

Readers of chest radiographs often comment on the presence of osteoporosis. We have hypothesized that diagnoses of osteoporosis from chest films are not reliable even when made by experienced radiologists. To test this hypothesis, we had nine radiologists estimate the degree of bone density seen on 45 lateral chest films. We compared their estimates of bone density to the results of dual photon bone densitometry of the lumbar spine. We found that there was little ability to accurately diagnose osteoporosis by chest film since the group of nine readers achieved accuracies ranging from 0.59 to 0.64. Therefore, we feel it is unjustified to comment upon the presence or absence of osteoporosis on the basis of chest films.

Technetium-99m RBC bleeding images in normal subjects: confusion with gastrointestinal bleeding sites

The normal appearance of a gastrointestinal bleeding study using labeled red blood cells has been discussed frequently, but the actual appearance is not well known. In this atlas article, the authors report on unusual findings in non-bleeding subjects and have tabulated the visualization of various structures. Vascular structures other than the aorta and inferior vena cava were seen in 42 of 48 patients. One or both kidneys were seen in 10 (21%) of 48 patients. The urinary bladder was seen in 23 (48%) of 48 patients, although gastric activity caused by free pertechnetate was never observed.

Technetium-99m hysterosalpingography in infertility: an accurate alternative to contrast hysterosalpingography

Thirteen infertile women who had undergone tubal surgery within the previous year for the correction of tubal obstruction, were studied with both conventional and radionuclide hysterosalpingography. The studies were performed on the same day, were interpreted independently, and the results were then compared. Three cases were excluded from analysis because of the technical inadequacy of one of the studies. Assuming the findings of the conventional studies to represent "truth," the sensitivity, specificity and accuracy of the radionuclide studies were 100%, 60% and 80% respectively.

Lingual thyroid: unusual appearance on computed tomography

A patient with a lingual thyroid was found to have inhomogeneous contrast enhancement on CT, findings not previously reported. Operative and histologic examination revealed marked thyroiditis and goitrous changes, explaining the CT findings.

Mechanical induction of osteogenesis: the importance of pin rigidity

Eight dogs, divided into two groups of four by varying pin rigidity, underwent 15% left tibial lengthening by the Ilizarov method. In group I, "tensioned" 1.6-mm wires maintained a rigidity approaching that of 4.0-mm pins. In group II, the wires, maintained at half the tension, averaged 45% of the rigidity measured in group I. All dogs in group I filled the experimental gap with de novo osteogenesis, whereas all of the dogs in group II prematurely bridged the gap, arresting the process of osteogenesis. From these experimental results, clinical trials have been started using commercially available external fixation devices utilizing pins with equivalent rigidity.

Stachyose Synthesis in Source Leaf Tissues of the CAM Plant Xerosicyos danguyi H. Humb

Leaf tissues from Xerosicyos danguyi H. Humb., a succulent member of the Cucurbitaceae, were found to possess both galactinol synthase activity and the capacity for photosynthetic production of stachyose, the phloem transport oligosaccharide common to other nonsucculent cucurbits. The amounts of stachyose isolated from leaf tissues, and the extractable activity of galactinol synthase, were somewhat higher in leaf tissues obtained from plants operating in the Crassulacean acid metabolism (CAM) mode (well watered plants) compared to leaf tissues from plants operating in the CAM-idling mode (water-stressed plants). In contrast, in leaf discs, the photosynthetic incorporation of label into stachyose following pulse labeling with (14)CO(2) was similar for stressed and for nonstressed tissues. Stachyose could be extracted from, and was synthesized photosynthetically by, leaf discs which contained no vascular tissues, indicating that synthesis of stachyose can occur in photosynthetic mesophyll cells of Xerosicyos.

Mechanical induction of Osteogenesis. Preliminary studies

The animal model developed in the Soviet Union by Ilizarov has been reliably reproduced by us for the mechanical induction of osteogenesis using slow distraction. Our preliminary studies in six adult dogs indicate that this osteogenesis originates from well-structured intramembranous ossification, with rapid maturation to lamellar bone, indistinguishable from surrounding host bone. Mineralization increases steadily, reaching critical levels for radiographic visualization between Days 21 and 28. In this model, the osteogenic area then exceeds normal bone density temporarily but returns to normal density within three months. Distraction for 28 consecutive days (at 0.25 millimeters every six hours using rigid transfixion wires, as Ilizarov describes) reliably lengthened the tibiae by 12 percent, increasing mass by 27 percent, and volume by 26 percent with only a one percent change in overall density. The process required four months to add 24 millimeters of mature, lamellar bone capable of full weight-bearing by the dogs. This rate of osteogenesis, estimated at 202 microns per day, is four times faster than a human's fastest growth plate (child's distal femur at 50 microns per day). Calcium/collagen ratios did not differ significantly from normal bone controls.

Indium-111 leukocyte accumulation in submandibular gland saliva as a cause for false-positive gut uptake in children

Unexplained false-positive accumulation of In-111 leukocyte in the gastrointestinal tract has been reported previously. In a pediatric population, uptake in the submandibular gland was noted in 19 of 42 children. This is believed to be a normal finding in children that is not seen in adults. In some of these 19 children, unexplained gastrointestinal activity was also noted. Saliva from a patient with false-positive gastrointestinal uptake and positive submandibular activity was positive for In-111. One suggested cause of unexplained gut activity may be secondary to swallowed activity in the saliva from the normal submandibular activity in children.

Early and delayed indium 111 leukocyte imaging in Crohn's disease

Twenty-seven patients with Crohn's disease were studied for the presence and location of activity by both early (4 h) and delayed (18-24 h) indium 111 leukocyte imaging. The results were compared with other parameters of disease activity including Crohn's disease activity index, barium studies, and endoscopy. There was a correlation between early images and Crohn's disease activity index (r = 0.78) and between delayed images and index (r = 0.82). Based upon the corresponding Crohn's disease activity index, the sensitivity of early and delayed imaging was 81.0% and 95.2%, respectively. Specificity of early and delayed imaging was 75.0% and 87.0%, respectively. Presence of activity on the early and delayed imaging agreed with activity on barium studies and colonoscopy in approximately 80% of cases. Correlation of location of disease by leukocyte imaging and x-ray was observed in 58.9% of early scans and 55.0% of delayed scans. Correlation of the location of disease by imaging and endoscopy was observed in 71.4% of early and 75.0% of delayed studies. Because of the possibility of occurrence of false-negative results in early images, delayed imaging should always be included in evaluation of disease activity in patients with Crohn's disease who are suspected of having mild activity. Delayed imaging is not required if the early imaging study clearly shows activity.

CT findings in abdominal actinomycosis

The diagnosis of abdominal actinomycosis is difficult because of its relative infrequency and imitation of other diseases. We present four cases in which these difficulties in diagnosis were experienced and show the utility of CT in suggesting this disease. Aspiration, biopsy, and proper culture technique, in conjunction with typical CT findings of transfascial and multiple organ involvement, led to the proper diagnosis in all cases.

Uptake of indium-111-labeled leukocytes by brain metastasis

Uptake of indium-labeled leukocytes was seen in two cases of histologically proven brain metastasis. In one, this led to misdiagnosis of the lesion as an abscess. On histological evaluation, a large number of white blood cells or macrophages was seen at the neoplastic sites. Reasons for leukocyte accumulation around metastatic brain neoplasms are discussed. In contrast to the current reports that indium-labeled leukocyte scans can differentiate intracranial infection from tumor, these cases demonstrate their lack of specificity in the detection of brain abscess.

Hyperdense parapelvic cyst confused with renal tumor

We have reported a case of a hyperdense parapelvic renal cyst that could not be easily differentiated from a solid tumor by multiple diagnostic studies. However, the typical findings of a hyperdense parapelvic cyst may allow less aggressive surgery.

Solitary splenic abscess: a new complication of splenic salvage treated by percutaneous drainage

A patient sustained a gunshot injury to the spleen. The spleen was left intact in an attempt to maintain normal immune function in the patient. The patient developed a splenic abscess as a result of the injury, a complication of splenic salvage that we have not found reported before. The abscess was treated successfully via CT-guided percutaneous drainage.

Submandibular uptake on indium-111 leukocyte scans in children

Report is made of false-positive localization of In-111 leukocytes in the submandibular gland area in children. Possible mechanisms are discussed, but this may represent a normal finding in children.

An autonomous functioning cystic thyroid adenoma. An unusual occurrence

An asymptomatic thyroid nodule that appeared cystic on ultrasound was seen in a 14-year-old girl. Tc-99m pertechnetate thyroid imaging was expected to show a cold nodule, but surprisingly revealed a hyperfunctioning nodule. A partial thyroidectomy revealed an hemorrhagic cystic adenoma. The occurrence of a cystic nodule, which continued to show hyperfunction, is unusual.

Radiation dosimetry considerations in the treatment of cystic suprasellar neoplasms

Methods and results are given to enable the computation of radiation dose as a function of depth in the wall of a suprasellar cyst containing radioactivity. Both beta- and gamma-emitting nuclides are considered. The methodology considers distribution of the radioactivity on the cyst wall (spherical shell geometry) and distribution uniformly in the fluid (volume geometry).

111 In-labeled leukocytes in the detection of prosthetic vascular graft infections

Making a clinical diagnosis of infection in prosthetic vascular grafts is difficult but when undiagnosed, this condition has a high mortality rate. Using Indium-111-labeled white-blood cells, 30 scans were performed in 21 patients suspected of having a prosthetic graft infection. The diagnosis of infected graft was confirmed by surgery in all cases, and lack of infection was established by resolution of symptoms with conservative therapy. Twenty-four hour scans of autologous Indium-111 leukocytes were obtained, and correlative CT studies were done in 11 cases. There were 13 infected grafts at surgery (purulent material present), and scans were positive in all (100% sensitivity); of 17 scans, there were 15 true negatives and two false positives (88% specificity). Using the criteria of gas or fluid around the graft, the sensitivity of CT was only 37% in a small subset of these patients. One-half of the cases in which infection was suspected clinically had no infection and had negative scans. Various types of grafts and graft materials were used, and there was no correlation with presence or absence of infection on the basis of the type of graft. Extragraft infection sites were found in five patients. In conclusion, use of Indium-111 leukocytes has been found to be an accurate and valuable diagnostic method for evaluation of suspected prosthetic vascular graft infection, and to have higher diagnostic accuracy than CT.

Precise intraoperative location of gastrointestinal bleeding with a hand-held counter. Work in progress

The nuclear medicine bleeding scan is frequently insufficient to locate sites of bleeding precisely, in spite of its great sensitivity. A small, hand-held Geiger-Müller counter, placed directly on exposed intestine in the operating room, enables precise location of the probable bleeding site. In three patients, the technique allowed a minimal amount of intestine to be resected, distinguished between large- and small-intestinal hemorrhage, and eliminated other foci as sites of bleeding.