OP0314 DOCK8 MUTATIONS IN COVID-19 AND MIS-C CYTOKINE STORM SYNDROME

Background:

We recently identified DOCK8 as a novel gene associated with cytokine storm syndrome (CSS)1. Heterozygous missense mutations in DOCK8 diminish NK cell lytic function and contribute to increased pro-inflammatory cytokine production (CSS). CSS is a potential complication of COVID-19 with severe consequences2. Children are at risk of a SARS-CoV-2 post-infectious CSS, multisystem inflammatory syndrome in children (MIS-C)3. Host genetic factors associated with COVID-19 CSS and MIS-C CSS are unknown.

Objectives:

The goals are to identify and functionally study rare mutations in DOCK8 in patients with SARS-CoV-2 COVID-19 and MIS-C.

Methods:

To date, 16 adult patients enrolled in a COVID-19 CSS clinical trial at UAB had whole genome sequencing. Four (25%) had rare heterozygous DOCK8 mutations (3 missense, 1 intronic). A COVID-19 CSS adult patient in Seattle also had a DOCK8 missense mutation. In addition, DOCK8 missense mutations were identified in five children (UAB & Northwell) hospitalized with MIS-C. DOCK8 mutations, or wild-type (WT) sequence controls, were introduced into human NK-92 cells by FOAMY virus transduction. WT and mutant DOCK8-expressing NK-92 cells were incubated with K562 target cells and compared for cytolysis and degranulation (CD107a).

Results:

One COVID-19 patient DOCK8 mutation (Gly523Arg) reduced NK cell degranulation by 30% and cytolysis by 23% (n=3) (Figure 1). Similar studies of 3 MIS-C patients with DOCK8 missense mutations (Arg899Trp, Ala2Thr, Pro687Leu) revealed up to 31% reduced NK cell degranulation and 48% reduction in cytolysis by 3 distinct mutations (n=3). Two-way ANOVA analysis revealed statistically significant (p<0.05) differences in NK cell degranulation and lysis for four unique DOCK8 mutations.

Conclusion:

Heterozygous DOCK8 missense mutations may contribute to severe COVID-19 and MIS-C CSS by partial dominant-negative effects yielding decreased NK cell cytolysis.

References:

[1]Schulert GS, Cron RQ. The genetics of macrophage activation syndrome. Genes Immun 2020:21:169-181.

[2] Cron RQ, Chatham WW. The rheumatologist’s role in COVID-19. J Rheumatol 2020:47:639-642.

[3]Reiff D, Mannion ML, Samuy N, Scalici P, Cron RQ. Distinguishing active pediatric COVID-19 from MIS-C. Pediatr Rheumatol Online J, in press.

Disclosure of Interests:

Randy Cron Consultant of: SOBI, Novartis, Pfizer, Sironax, Grant/research support from: SOBI, Mingce Zhang: None declared, Remy Cron: None declared, Devin Absher: None declared, John Bridges: None declared, Amanda Schnell: None declared, Pavan Bhatraju: None declared, Anshul Vagrecha: None declared, Shannon Lozinsky: None declared, Suchitra Acharya: None declared, Carolyn Levy: None declared, Winn Chatham Grant/research support from: SOBI.

DOCK8 mutations in COVID-19 and MIS-C Cytokine Storm Syndrome

Background

We recently identified DOCK8 as a novel gene associated with cytokine storm syndrome (CSS). Heterozygous missense mutations in DOCK8 diminish NK cell lytic function and contribute to increased pro-inflammatory cytokine production (CSS). CSS is a potential complication of COVID-19 with severe consequences. Children are at risk of a SARS-CoV-2 post-infectious CSS, multisystem inflammatory syndrome in children (MIS-C). Host genetic factors associated with COVID-19 CSS and MIS-C CSS are unknown.

Methods

To date, 16 adult patients enrolled in a COVID-19 CSS clinical trial at UAB had whole genome sequencing. Four (25%) had rare heterozygous DOCK8 mutations (3 missense, 1 intronic). A COVID-19 CSS adult patient in Seattle also had a DOCK8 missense mutation. In addition, DOCK8 missense mutations were identified in 5 children (UAB & Northwell) hospitalized with MIS-C. DOCK8 mutations, or wild-type (WT) sequence controls, were introduced into human NK-92 cells by FOAMY virus transduction. WT and mutant DOCK8-expressing NK-92 cells were incubated with K562 target cells and compared for cytolysis and degranulation (CD107a).

Results

One COVID-19 patient DOCK8 mutation (Gly523Arg) reduced NK cell degranulation by 30% and cytolysis by 23% (n=3). Similar studies of 3 MIS-C patients with DOCK8 missense mutations revealed up to 31% reduced NK cell degranulation and 48% reduction in cytolysis by 3 mutations (n=3). Two-way ANOVA analysis revealed statistically significant (p&lt;0.05) differences in NK cell degranulation and lysis for 4 unique DOCK8 mutations.

Conclusion

Heterozygous DOCK8 missense mutations may contribute to severe COVID-19 and MIS-C CSS by partial dominant-negative effects yielding decreased NK cell cytolysis.

Impact of exercise on bone mineral density, fall prevention, and vertebral fragility fractures in postmenopausal osteoporotic women

Osteoporosis is the most prevalent bone disease worldwide and predisposes affected individuals to fragility fractures. Exercise has been shown to have multiple health benefits in post-menopausal osteoporotic women, but often recommendations regarding the benefits of specific exercise types are vague. Improving bone mineral density (BMD) is an essential component in any program to prevent osteoporotic vertebral fractures. The objective of this report is to briefly review the current understanding on the impact of exercise on BMD in postmenopausal women as it pertains to fragility fractures. Broad categories of exercises include aerobic, resistance, stretching, and balance. Tai Chi, Yoga, and Pilates are a heterogeneous group of specific exercise modalities that can span multiple categories. Current literature suggests that only resistance type exercises have a convincing impact on BMD. Core-strengthening exercises and attention to posture/balance can help mitigate falls. A number of barriers affect patient compliance and accessibility to exercise. In summary, exercise should be included in any multi-modality osteoporosis treatment plan with the goal of sustained exercise throughout life. If possible, osteoporotic women should be on a resistance-based regimen incorporating weight-bearing exercises, and also target posture and balance. Healthcare providers and educators should have resources readily available for patients.

A Case of Heart Failure in a Patient With Systemic Lupus Erythematosus

Patients with systemic lupus erythematosus (SLE) can present with multiple cardiovascular pathologies, including pulmonary hypertension, valvular disease, pericarditis, myocarditis, and premature atherosclerosis. SLE medications can also cause cardiovascular side effects. We present a patient who developed a severe cardiomyopathy secondary to the hydroxychloroquine prescribed to treat her SLE. (Level of Difficulty: Beginner.).

6110OCT guidance during primary PCI may increase long-term risk of device oriented events: subanalysis of ROBUST study

Background

Optical coherence tomography (OCT) guidance in primary percutaneous coronary intervention (pPCI) is expected to be safe in short and mid-term follow-up. Long term merits or risks of OCT guidance are unknown.

Purpose

To assess the possible merits of OCT guidance in pPCI in long-term follow-up.

Methods

201 patients with ST-elevation myocardial infarction (STEMI) were enrolled in this study. Patients were randomized either to pPCI alone (angio-guided group, n=96) or to pPCI with OCT guidance (OCT-guided group, n=105) and also either to biolimus A9 or to everolimus-eluting stent implantation. The OCT study was performed after PCI with C7-XRTM intravascular imaging system employing a non-occlusive technique.

Incidence of Device-oriented Composite Endpoints (DoCE) was compared in both study groups. DoCE were defined as composite of definite or possible cardiovascular death, myocardial infarction and target vessel revascularization. The search for DoCE was performed by means of medical check-ups, repeated telephone contacts, analysis of medical records and search in national population registry.

Results

Mean follow-up was 6.5 (6.5–7.1 years). Of these patients, 2 (1.0%) patients died of cardiovascular reason, 4 patients (2%) suffered myocardial infarction and 7 (3.5%) patients underwent target lesion revascularization. In OCT guided group, number of stents per patient was higher (1.4 vs. 1.2, p=0.03). Risk of DoCE was significantly higher in OCT-guided group (7.6% vs. 2.1%, p=0.023).

Event-free survival in study groups

Conclusion

Our data suggest increased risk of adverse events related to OCT guided tailoring of stent implantation performed after pPCI. These findings should be confirmed by further randomised trials with higher statistical power.

Acknowledgement/Funding

The work was supported by a long-term organization development plan 1011 (FMHS)

The game of telephone: a sustained, low-cost, quality improvement initiative to enhance communication between patients and their resident physician

This multidisciplinary quality improvement project was designed to enhance telephone communication between patients and their resident physician while concomitantly creating a standardised telephone communication protocol for resident internal medicine continuity clinics. The plan, do, study, act (PDSA) quality improvement framework model was applied for four distinct cycles. Baseline data were collected regarding open telephone encounters. The initial intervention entailed targeted communication to specific individual residents with open telephone encounters more than one SD above the average. The next cycle involved developing a novel communication process map that was distributed to faculty preceptors and clinic anchor nurses. The faculty preceptors then disseminated the new policies and communication algorithm to resident physicians. Finally, new resident and anchor nurses were educated about the standardised processes through scheduled orientation activities. After 19 months of implementation of this project with four PDSA cycles, resident open telephone encounters decreased by 40.7%. Resident telephone communication in continuity clinics can be improved through targeted individualised communication, implementation of a standardised telephone communication protocol, dissemination of communication algorithms to clinic faculty, residents and nurses and ongoing education to all parties through orientation activities to instil a self-sustaining culture change.

HIV infection is associated with decreased thrombin generation

BACKGROUND

Excess risk of cardiovascular disease occurs in effectively treated individuals with human immunodeficiency virus (HIV) infection. Although elevated plasma D-dimer levels are associated with increased morbidity and mortality, the impact of HIV infection on coagulation in vivo has not been well studied.

METHODS

We measured D-dimers, antithrombin, endogenous thrombin potential (ETP; a functional measure of thrombin generation in vitro), thrombin/antithrombin complexes (TAT; a measure of thrombin generation in vivo), tissue factor, prothrombin fragment 1 + 2 (F1+2), and normalized APC sensitivity ratio (nAPCsr) in 199 HIV-positive men who were receiving antiretroviral therapy and had an undetectable HIV RNA level, in 79 HIV-positive untreated men, and in 39 uninfected controls.

RESULTS

Median antithrombin levels were higher while the ETP was lower among HIV-infected adults (treated and untreated), compared with controls. There were few differences between coagulation markers in the 2 HIV groups. Compared with controls, the nAPCsr was lower in treated men and the TAT level was lower in untreated individuals. We observed little difference among measured levels of D-dimer, tissue factor, or F1+2 between HIV-infected individuals and controls. Antiretroviral therapy exposure was associated with a lower antithrombin level, a lower nAPCsr, and a lower ETP, while history of opportunistic infection was associated with a higher nAPCsr.

CONCLUSIONS

HIV infection is associated with decreased thrombin generation, as measured by the ETP, and an increased antithrombin level. These data suggest that HIV infection may not be associated with increased propensity toward clotting, as has been suggested on the basis of isolated measures of D-dimer levels.

Carotid Intima-Media Thickness Progression in HIV-Infected Adults Occurs Preferentially at the Carotid Bifurcation and Is Predicted by Inflammation

Background

Shear stress gradients and inflammation have been causally associated with atherosclerosis development in carotid bifurcation regions. The mechanism underlying higher levels of carotid intima-media thickness observed among HIV-infected individuals remains unknown.

Methods and Results

We measured carotid intima-media thickness progression and development of plaque in the common carotid, bifurcation region, and internal carotid artery in 300 HIV-infected persons and 47 controls. The median duration of follow-up was 2.4 years. When all segments were included, the rate of intima-media thickness progression was greater in HIV-infected subjects compared with controls after adjustment for traditional risk factors (0.055 vs. 0.024 mm/year, P=0.016). Rate of progression was also greater in the bifurcation region (0.067 vs. 0.025 mm/year, P=0.042) whereas differences were smaller in the common and internal regions. HIV-infected individuals had a greater incidence of plaque compared with controls in the internal (23% vs. 6.4%, P=0.0037) and bifurcation regions (34% vs. 17%, P=0.014). Among HIV-infected individuals, the rate of progression in the bifurcation region was more rapid compared with the common carotid, internal, or mean intima-media thickness; in contrast, progression rates among controls were similar at all sites. Baseline hsCRP was elevated in HIV-infected persons and was a predictor of progression in the bifurcation region.

Conclusions

Atherosclerosis progresses preferentially in the carotid bifurcation region in HIV-infected individuals. hsCRP, a marker of inflammation, is elevated in HIV and is associated with progression in the bifurcation region. These data are consistent with a model in which the interplay between hemodynamic shear stresses and HIV-associated inflammation contribute to accelerated atherosclerosis. (J Am Heart Assoc. 2012;1:jah3-e000422 doi: 10.1161/JAHA.111.000422.)

Clinical Trial Registration

URL: http://clinicaltrials.gov. Unique identifier: NCT01519141

Carotid intima-media thickness among human immunodeficiency virus-infected patients without coronary calcium

Subjects infected with human immunodeficiency virus (HIV) have increased risk for atherosclerosis. Carotid artery intima-media thickness (IMT) assessed using ultrasound and coronary artery calcium (CAC) detected using computed tomography predict cardiovascular risk in the general population; however, their usefulness and comparability in patients with HIV are less well defined. The purpose of this study was to compare IMT and CAC in the detection of atherosclerosis in subjects with HIV. CAC and IMT were measured in 253 HIV-infected and 58 uninfected adults. Associations among HIV-related factors, traditional risk factors, and CAC and IMT were evaluated. The distribution of IMT among subjects with and without CAC was compared. Among the patients with HIV, 37% had detectable CAC compared to 28% of controls (p = 0.19); 16% of the patients with HIV had CAC >100 compared to 5% of controls (p = 0.03). With either detectable or undetectable CAC, HIV-infected subjects had higher IMT compared to controls (1.02 ± 0.34 vs 0.78 ± 0.12 mm, p <0.0001), even after adjustment for traditional risk factors. Among those with undetectable CAC, 34% of patients with HIV had markedly increased IMT (≥1 mm) compared to no controls (p <0.0001). HIV-related factors were associated with IMT but not with CAC. In conclusion, patients with HIV and controls had similar rates of detectable CAC, while absolute CAC scores were modestly higher in the HIV group. Conversely, carotid IMT detected advanced subclinical atherosclerosis in patients with HIV even in the absence of CAC. Thus, with HIV, IMT is associated with disease-related factors and may be a more sensitive indicator of subclinical atherosclerosis than CAC.

Association of vitamin D insufficiency with carotid intima-media thickness in HIV-infected persons

We observed an independent association between vitamin D insufficiency and higher carotid intima-media thickness in a cross-sectional analysis of 139 HIV-infected persons. If confirmed, these findings support a clinical trial of vitamin D supplementation to reduce cardiovascular events in HIV-infected persons.

Impact of HIV infection on diastolic function and left ventricular mass

BACKGROUND

Patients with HIV have increased risk for cardiovascular disease, but the underlying mechanisms remain unknown. The purpose of this study was to determine the prevalence of echocardiographic abnormalities among asymptomatic HIV-infected individuals compared with HIV-uninfected individuals. Methods/Results- We performed echocardiography in 196 HIV-infected adults and 52 controls. Left ventricular ejection fraction, left ventricular mass indexed to the body surface area, and diastolic function were assessed according to American Society of Echocardiography standards. Left ventricular mass index was higher in HIV-infected patients (77.2 g/m(2) in patients with HIV versus 66.5 g/m(2) in controls, P<0.0001). Left ventricular ejection fraction was similar in both groups. Eight (4%) of the patients with HIV had evidence of left ventricular systolic dysfunction (defined as an EF <50%) versus none of the controls; 97 (50%) had mild diastolic dysfunction compared with 29% of the HIV-uninfected subjects (P=0.008). After adjustment for hypertension and race, HIV-infected participants had a mean 8 g/m(2) larger left ventricular mass index compared with controls (P=0.001). Higher left ventricular mass index was independently associated with lower nadir CD4 T-cell count, suggesting that immunodeficiency may play a role in this process. After adjustment for age and traditional risk factors, patients with HIV had a 2.4 greater odds of having diastolic dysfunction as compared with controls (P=0.019).

CONCLUSIONS

HIV-infected patients had a higher prevalence of diastolic dysfunction and higher left ventricular mass index compared with controls. These differences were not readily explained by differences in traditional risk factors and were independently associated with HIV infection. These results suggest that contemporary asymptomatic patients with HIV manifest mild functional and morphological cardiac abnormalities, which are independently associated with HIV infection.

Ezetimibe alone reduces low-density lipoprotein cholesterol in HIV-infected patients receiving combination antiretroviral therapy

In this crossover study of ezetimibe monotherapy in 48 antiretroviral-treated patients with human immunodeficiency virus infection, the mean changes in low-density lipoprotein cholesterol were -5.3% (-11 mg/dL) and +5.5% (+4 mg/dL) with ezetimibe treatment and placebo, respectively (P = .04). Ezetimibe was safe and effective in reducing low-density lipoprotein cholesterol and is an option for patients who cannot tolerate treatment with a statin.

Distribution of estrogens, 17beta-estradiol and estrone, in Canadian municipal wastewater treatment plants

The distribution of female hormones, 17beta-estradiol and estrone, was determined in effluents of 18 selected municipal treatment plants across Canada. Replicate 24-h composite samples were collected from the influent and final effluent of each treatment plant, and the removal efficiency compared to the operational characteristics of the plants. In conventional activated sludge and lagoon treatment systems, the mean concentrations of 17beta-estradiol and estrone in influent were 15.6 ng/l (range 2.4-26 ng/l) and 49 ng/l (19-78 ng/l). In final effluents, the mean concentrations of both 17beta-estradiol and estrone were reduced to 1.8 ng/l (0.2-14.7 ng/l) and 17 ng/l (1-96 ng/l), respectively. 17beta-estradiol was removed effectively, >75% and as high as 98%, in most of the conventional mechanical treatment systems with secondary treatment. The removal of estrone was much more complex with removal varying from 98% to situations where the concentrations in the effluent were elevated above that detected in the influent. The estrogenicity, measured using a transfected estrogen receptor in yeast (YES) assay, was also variable, ranging from high removal to elevations of estrogenicity in final effluent. Although the apparent removals were not statistically correlated with either hydraulic (HRT) or solid (SRT) retention times, plants or lagoons with high SRT were very effective at reducing the levels of hormones. Well-operated plants that achieved nitrification also tended to have higher removal of hormones than those that did not nitrify. Laboratory aerobic reactor experiments confirmed the rapid removal of 17beta-estradiol, estrone, and estrogenicity when exposed to sewage slurries.

Objective threshold selection procedure (OTS) for segmentation of scanning laser confocal microscope images

The determination of volumes and interface areas from confocal laser scanning microscopy (CLSM) images requires the identification of component objects by segmentation. An automated method for the determination of segmentation thresholds for CLSM imaging of biofilms was developed. The procedure, named objective threshold selection (OTS), is a three-dimensional development of the approach introduced by the popular robust automatic threshold selection (RATS) method. OTS is based on the statistical properties of local gray-values and gradients in the image. By characterizing the dependence between a volumetric feature and the intensity threshold used for image segmentation, the former can be determined with an arbitrary confidence level, with no need for user intervention. The identification of an objective segmentation procedure renders the possibility for the full automation of volume and interfacial area measurement. Images from two distinct biofilm systems, acquired using different experimental techniques and instrumental setups were segmented by OTS to determine biofilm volume and interfacial area. The reliability of measurements for each case was analyzed to identify optimal procedure for image acquisition. The automated OTS method was shown to reproduce values obtained manually by an experienced operator.

Evaluation of fluorescently labeled lectins for noninvasive localization of extracellular polymeric substances in Sphingomonas biofilms

Three strains of Sphingomonas were grown as biofilms and tested for binding of five fluorescently labeled lectins (Con A-type IV-TRITC or -Cy5, Pha-E-TRITC, PNA-TRITC, UEA 1-TRITC, and WGA-Texas red). Only ConA and WGA were significantly bound by the biofilms. Binding of the five lectins to artificial biofilms made of the commercially available Sphingomonas extracellular polysaccharides was similar to binding to living biofilms. Staining of the living and artificial biofilms by ConA might be explained as binding of the lectin to the terminal mannosyl and terminal glucosyl residues in the polysaccharides secreted by Sphingomonas as well as to the terminal mannosyl residue in glycosphingolipids. Staining of the biofilms by WGA could only be explained as binding to the Sphingomonas glycosphingolipid membrane, binding to the cell wall, or nonspecific binding. Glycoconjugation of ConA and WGA with the target sugars glucose and N-acetylglucosamine, respectively, was used as a method for evaluation of the specificity of the lectins towards Sphingomonas biofilms and Sphingomonas polysaccharides. Our results show that the binding of lectins to biofilms does not necessarily prove the presence of specific target sugars in the extracellular polymeric substances (EPS) in biofilms. The lectins may bind to non-EPS targets or adhere nonspecifically to components of the biofilm matrix.

Microembolic signals and clinical outcome in patients with acute stroke--a prospective study

The occurrence of microembolic signals (MES) in patients with transient ischemic attack (TIA) or stroke has already been described; the influence of the time interval between onset of symptoms and transcranial Doppler monitoring (TCD) on the MES rate or MES prevalence and the possible prognostic value of the early detected MES rate on the outcome of TIA or stroke symptoms in a 3 month interval are discussed. In a prospective study we evaluated 61 patients consecutively admitted to our stroke unit after their first ischemic neurological deficit involving the vascular territory of MCA and/or ACA. All of the patients underwent a 30-minute bilateral transcranial Doppler monitoring of their MCAs for the identification of MES. Monitoring was performed within 12.3 + -9.3 (average mean + -SD) hours of stroke onset for the first time, the second time 48 hours after first TCD monitoring. Prognosis for the recovery of neurological deficits was evaluated by using the Barthel index (BI) and Scandinavian Stroke Scale (SSS) at the time of admission of the patient to the stroke unit, and with Barthel indices after one month and after 3 months. As a result, 56% of all patients showed MES in at least one of the two registrations. MES were recorded not only on the symptomatic side. The MES prevalence between both TCD monitorings was significantly different (total MES prevalence: 1st TCD: 26 patients: 2nd TCD: 13 patients; p < 0.04; ipsilateral MES prevalence: 1st TCD: 19 patients; 2nd TCD: 9 patients; p < 0.01). The regression analysis showed a significant influence of the total MES rate on both neurological scores at admission (SSS: 0.03; Barthel index: 0.04), but not for the Barthel scores after one and three months. In conclusion, we found an influence of the time interval between onset of neurological symptoms of TIA or stroke on the MES rate and the prevalence of MES. The prevalence of MES or the MES rate, found after a short time interval to the onset of symptoms, did not have a prognostic value on the outcome of neurological deficits up to a three month follow-up.

Validation of a Telephone Cognitive Assessment Battery

OBJECTIVE

To present and evaluate an instrument, the Telephone Cognitive Assessment Battery (TCAB), designed to be administered over the telephone to assess the cognitive status of older individuals. The TCAB addresses mental status, reasoning and executive ability, primary and secondary memory, and language. It consists of six neuropsychological tests and takes approximately 15 to 20 minutes to complete.

DESIGN

The instrument is evaluated with a comparative cross-sectional design, with data collected both prospectively and retrospectively.

SETTING

The University Hospitals of Cleveland/Case Western Reserve University Alzheimer Center Research Registry.

PARTICIPANTS

Forty Alzheimer's Disease cases selected from among those most recently recruited into the Registry and 40 cognitively intact Registry controls. Controls were selected randomly so that the two groups had similar distributions of age, sex, and education.

MEASUREMENTS

The cognitive status of all participants was assessed utilizing both the TCAB and the usual in-person Registry evaluation, which includes medical history data and in-person assessment of cognitive status. In order to measure the potential learning effect of repeated testing, half of the cases and half of the controls were recruited and assessed over the telephone with the TCAB before their in-person Registry evaluation (with a waiting period of at least 2 weeks between evaluations), whereas the other two halves received the TCAB after they had become part of the Registry. The TCAB was administered to all participants by a single investigator. Two clinical evaluators, blinded to the Registry diagnosis of the subjects, independently classified the subjects as cognitively impaired, normal, or questionable on the basis of the results of the TCAB and a brief listing of medical illness and depressive symptoms. A final classification was achieved through consensus and subsequently compared with the Registry diagnosis, taken here to be the gold standard.

RESULTS

Test scores of subjects assessed by TCAB before receiving the in-person assessment were compared with those of subjects receiving the in-person assessment first. There were no significant differences between mean scores of the two groups (those with TCAB first and those with TCAB last) for either cases or normal controls. High values of the kappa statistic were obtained for the two initial evaluators of the TCAB classification, demonstrating excellent interrater reliability. Regarding the reconciled TCAB classification, the ability of the TCAB to correctly classify subjects according to cognitive status, while controlling for potential confounders such as age and educational level, was assessed by means of discriminant analysis techniques. Knowledge of the TCAB classification and age allowed the correct classification of 95% of the participants; this was not significantly improved by knowledge of other potential determinants. Sensitivity and specificity were calculated under two schema for classifying those subjects in the "questionable" category. Positive and negative predictive values of the TCAB were computed assuming a prevalence of cognitive impairment of 10% in the older population. High negative predictive values (over 99%) were obtained under both schema, whereas the positive predictive values were seen to be more dependent on the classification of questionables.

CONCLUSION

Research studies involving ascertainment of cognitive status of older people, particularly those that require periodic follow-up, such as those focusing on healthy aging, commonly suffer from lack of representativeness of subjects, often brought about by problems related to mobility of potential participants. It is also crucial that normal individuals who are recruited initially to serve as controls in epidemiologic studies of dementing illnesses be reevaluated periodically, and this may be hindered by the same obstacles. (ABSTRACT TRUNCATED)

Blockade of bradykinin B2 receptors prevents the increase in capillary density induced by chronic angiotensin-converting enzyme inhibitor treatment in stroke-prone spontaneously hypertensive rats

We investigated the mechanism of action of the ACE inhibitor-induced increase in cardiac capillary length density. Stroke-prone spontaneously hypertensive rats were treated prenatally and up to the age of 20 weeks with the ACE inhibitor ramipril (0.01 and 1 mg/kg per day PO) and the AT1 receptor antagonist losartan (30 mg/kg per day PO). The contribution of endogenous bradykinin potentiation to the ACE inhibitor actions was assessed by cotreatment with the bradykinin B2-receptor antagonist Icatibant (0.5 mg/kg per day, SC via osmotic minipumps) from 6 to 20 weeks of age. At the end of the treatment period, cardiac capillary length density was measured stereologically using the orientator method. The development of hypertension and left ventricular hypertrophy was prevented by high- but not low-dose ramipril and was not affected by chronic bradykinin B2-receptor blockade. Low- and high-dose ramipril significantly increased cardiac capillary length density (3577 +/- 279, n = 11 and 3988 +/- 300 mm/mm3; n = 10; P < .05) compared with vehicle-treated animals (2935 +/- 137 mm/mm3; n = 13). These effects were abolished by chronic bradykinin B2-receptor blockade. The bradykinin antagonist alone was without effect on cardiac capillary length density. Losartan prevented hypertension and left ventricular hypertrophy but did not significantly alter cardiac capillary length density (3429 +/- 309 mm/mm3; n = 7). Our results demonstrate that chronic ACE inhibitor treatment can increase cardiac capillary length density in stroke-prone spontaneously hypertensive rats independently of a reduction in blood pressure or left ventricular hypertrophy. This effect is related to the ACE inhibitor-induced potentiation of endogenous bradykinin since it was prevented by chronic bradykinin B2-receptor blockade and was not observed following antihypertensive treatment with the AT1-receptor antagonist losartan.

Defense mechanisms in Peyer's patches and mesenteric lymph nodes against Yersinia enterocolitica involve integrins and cytokines

Adhesion molecules and cytokines are involved in regulation of cellular host responses in infection processes. In this study the roles of the integrins Mac-1 and VLA-4, as well as those of the cytokines tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma), in defense mechanisms against Yersinia enterocolitica in Peyer's patches (PP) and mesenteric lymph nodes (MLN) were investigated by blocking these molecules with antibodies in vivo prior to orogastric Yersinia infection. Intestinal Yersinia infection caused abscesses composed of polymorphonuclear (Mac-1+ VLA-4+ Pgp-1+ ICAM-1-) and mononuclear (Mac-1+ VLA-4+ Pgp-1+ ICAM-inhibited phagocytosis of yersiniae by macrophages, (ii) reduced Yersinia-specific proliferation and IFN-gamma production of T cells from PP and MLN, and (iii) caused increased bacterial growth in PP and MLN followed by profound tissue destruction. Neutralization of TNF-alpha or IFN-gamma had comparable effects, suggesting that cell-mediated host responses including activated macrophages are required for control of yersiniae in intestinal tissues. The number of Mac-1+ cells in PP and MLN increased after yersinia infection, and recruitment of these cells was not blocked by administration of anticytokine or anti-integrin antibodies. While anti-VLA-4, -TNF-alpha, or -IFN-gamma antibody treatment caused an increased dissemination of yersiniae from PP to the spleen systemic dissemination was reduced by anti-Mac-1 antibodies. The results of this study suggest that the cytokines IFN-gamma and TNF-alpha as well as the integrins Mac-1 and VLA-4 are involved in protective cellular host defense mechanisms in PP and MLN against Y. enterocolitica, the latter probably being involved in both cell-cell and cell-pathogen interactions.

Effect of low-dose treatment with perindopril on cardiac function in stroke-prone spontaneously hypertensive rats: role of bradykinin

Angiotensin-converting enzyme (ACE) inhibitors can improve cardiac function independent of their blood pressure (BP)-lowering actions. We investigated the effect of chronic subantihypertensive ACE inhibitor treatment on functional and biochemical cardiac parameters in stroke-prone spontaneously hypertensive rats (SHRSP). Animals were treated in utero and subsequently to age 20 weeks with the ACE inhibitor perindopril (0.01 mg/kg/day). The contribution of endogenous bradykinin (BK) potentiation to the actions of the ACE inhibitor was assessed by cotreatment with the BK beta 2-receptor antagonist Hoe 140 (500 micrograms/kg/day subcutaneously, s.c.) from age 6 to 20 weeks and by measurement of myocardial prostacyclin and cyclic GMP concentrations. Chronic low-dose perindopril treatment had no effect on development of hypertension and left ventricular hypertrophy (LVH), but perindopril improved cardiac function, as demonstrated by increased LV pressure (LVP) (19.4%) and LVdp/dtmax (27.8%) but no change in heart rate (HR). The activities of lactate dehydrogenase (LDH) and creatine kinase (CK) as well as lactate concentrations in the coronary venous effluent were reduced by 39.3, 50, and 60.6%, respectively. Myocardial tissue concentrations of glycogen and the energy-rich phosphates ATP and CK were increased by 16.3, 33.1, and 28.2%, respectively. All ACE inhibitor-induced effects on cardiac function and metabolism were abolished by concomitant chronic BK receptor blockade. Cardiac prostacyclin concentrations were threefold elevated in perindopril-treated animals whereas cardiac cyclic GMP concentration remained unchanged as compared with that of controls. Our data demonstrate that chronic low-dose ACE inhibitor treatment can improve cardiac function and metabolism by potentiating endogenous BK.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-converting enzyme inhibition improves cardiac function. Role of bradykinin

The effect of chronic low- and high-dose treatment with the angiotensin-converting enzyme (ACE) inhibitor ramipril (0.01 and 1 mg/kg per day) on the development of hypertension and left ventricular hypertrophy as well as on functional and biochemical alterations of the heart was studied in stroke-prone spontaneously hypertensive rats treated prenatally and subsequently up to the age of 20 weeks. The contribution of endogenous bradykinin potentiation to the ACE inhibitor actions was assessed by cotreatment of rats with the bradykinin B2-receptor antagonist Hoe 140 (500 micrograms/kg per day SC) from 6 to 20 weeks of age. High- but not low-dose ACE inhibitor treatment prevented the development of hypertension and left ventricular hypertrophy. Chronic bradykinin receptor blockade did not attenuate the antihypertensive and antihypertrophic actions of ramipril. High-dose ramipril treatment improved cardiac function, as demonstrated by an increase in left ventricular pressure (29.9%), dP/dtmax (34.9%), and coronary flow (22.1%), without a change in heart rate. The activities of lactate dehydrogenase and creatine kinase and lactate concentration in the coronary effluent were reduced by 39.3%, 55.5%, and 66.7%, respectively. Myocardial tissue concentrations of glycogen and the energy-rich phosphates ATP and creatine phosphate were increased by 31.3%, 39.9%, and 73.7%, respectively, whereas lactate was decreased by 20.8%. Chronic low-dose ACE inhibitor treatment led to a pattern of changes in cardiodynamics and cardiac metabolism similar to that observed with the high dose. All ACE inhibitor-induced effects on cardiac function and metabolism were abolished by chronic bradykinin receptor blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term low-dose angiotensin converting enzyme inhibitor treatment increases vascular cyclic guanosine 3',5'-monophosphate

We investigated functional changes in aortic preparations of spontaneously hypertensive rats treated in utero and subsequently up to 20 weeks of age with the angiotensin converting enzyme (ACE) inhibitors ramipril (0.01 and 1 mg/kg per day) and perindopril (0.01 mg/kg per day). Early-onset treatment with the high dose of ramipril inhibited aortic ACE activity, prevented the development of hypertension, increased aortic vasodilator responses to acetylcholine (10(-8) to 10(-6) mol/L), decreased vasoconstrictor responses to norepinephrine (10(-8) mol/L), and increased aortic cyclic GMP content by 160%. Low-dose ramipril inhibited aortic ACE activity and attenuated the aortic vasoconstrictor response to norepinephrine but had no effect on blood pressure. Low-dose treatment with ramipril and perindopril resulted in a significant increase in aortic cyclic GMP content by 98% and 77%, respectively. Long-term coadministration of the bradykinin B2-receptor antagonist Hoe 140 abolished the ACE inhibitor-induced increase in aortic cyclic GMP. Our data demonstrate that long-term treatment with ACE inhibitors can alter vascular function of compliance vessels independently of the antihypertensive action. The increase in aortic cyclic GMP was due to bradykinin potentiating the action of the ACE inhibitors.

Vascular remodeling in systemic hypertension

It is now well accepted that treatment of hypertension must extend beyond the mere control of blood pressure. Among the objectives "beyond blood pressure control" is the remodeling of resistance and compliance vessels that have usually undergone a process of hypertrophy and/or hyperplasia. Salutary vascular remodeling by antihypertensive treatment not only implies structural changes of the vascular wall, but also functional improvements, including diminished contractile responses to endogenous vasoconstrictors and enhanced relaxation to endogenous vasodilators. We have treated spontaneously hypertensive rats with the angiotensin-converting enzyme (ACE) inhibitors zabicipril, perindopril, and ramipril at antihypertensive and sub-antihypertensive doses and have analyzed vascular morphology and function. Chronic oral treatment was begun before hypertension developed (prevention study). Remodeling of mesenteric vessels with, inter alia, a reduction of the media:lumen ratio was achieved by antihypertensive doses of the drugs. Further, vascular function was improved not only after high-dose, but also after low-dose ACE inhibitor treatment, as tested in the aortic vessels: an inhibition of vascular ACE was associated with attenuated vasoconstrictor responses to norepinephrine and enhanced dilator responses to acetylcholine. In addition, low and high doses significantly increased aortic cyclic guanosine monophosphate (cGMP) content, suggesting an improved vasodilator capacity. Our data demonstrate that improvements of vascular function can be achieved by ACE inhibitors, independently of structural changes and of the antihypertensive action exerted by these drugs.

[Antibiotic treatment for diabetic foot. Advantages of intravenous regional route as alternative for systemic route]

Diabetic angiopathy prevents adequate access of antibiotic agents to septic areas of the diabetic foot. We treated 22 such patients with antibiotics infused through a superficial vein associated to tourniquet occlusion of the limb (Group A). A control group of 47 patients, similar in age, sex and severity of diabetes received conventional systemic therapy (Group B). 45% of the patients exhibited occlusive arterial disease. Surgery was performed by the same team in both groups. Group A received regional anesthesia at the same time of the first antibiotic infusion. Group B received general or spinal anesthesia. Amputation was required in 5% of patients in Group A compared to 30% of patients in Group B (p < 0.02). Hospital stay was also significantly shorter in patients from Group A. No complications of this form of therapy were observed. Thus, regional antibiotic therapy may improve prognosis and facilitate management in patients with septic diabetic foot.

Tissue culture of human fetal pancreas. Development and function of B-cells in vitro and transplantation of explants to nude mice

The present study evaluates the development and function of human fetal B-cells in vitro with a view to using such cells in future attempts for transplantation of human fetal pancreas to diabetic patients. A method previously described in our laboratory for preparing islets in vitro from the fetal rat pancreas has been applied and modified for use with human fetal pancreas. Pancreatic glands of different gestational ages were obtained from 37 consecutive prostaglandin-induced abortions. After a mild collagenase treatment, the partially disintegrated tissue was maintained in culture for 7 days in tissue culture medium RPMI 1640 plus 20% fetal calf serum to permit cell attachment and out-growth of endocrine cells. In 17 of the 37 consecutively cultured fetal pancreatic glands, islet-like cell clusters were formed. The 20 remaining glands were lost because of either bacterial contamination or lack of viability already before dissection had occurred. Sections of the newly formed cell clusters revealed well-preserved pancreatic cells showing frequent mitotic figures. The tissue exhibited a high rate of (pro)insulin biosynthesis and a modest insulin response to secretory stimuli, suggesting that the mechanism of glucose regulation by the fetal B-cells is not yet fully developed. Electron micrographs showed a large number of granule-containing cells, some of which were identified as B-cells. In nine cases, harvested cell clusters were implanted beneath the kidney capsule of nude mice. When these animals were killed after 2 mo, seven mice showed a considerable growth of the grafts with numerous islet-like structures containing insulin- and glucagon-positive cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term effects of cyclosporin A on cultured mouse pancreatic islets

In the light of recent attempts to treat newly-diagnosed Type 1 (insulin-dependent) diabetic patients with cyclosporin A, and reports suggesting an impaired glucose tolerance following immunosuppression therapy with cyclosporin A, we investigated the long-term effects of cyclosporin A on islet beta-cell morphology and function in vitro. Collagenase-isolated mouse pancreatic islets were cultured free-floating for 7 days in medium RPMI 1640 + 10% calf serum in the presence of cyclosporin A (0.1 or 1.0 mg/l). Islets cultured in the presence of the higher cyclosporin A concentration had impaired islet proinsulin biosynthesis and insulin release when challenged with high glucose concentration. Moreover, the insulin content of the drug-exposed islets was decreased and so was the rate of DNA synthesis. The glucose oxidation and respiratory rates, however, remained unaffected, suggesting that the impaired insulin production was not a result of defective oxidative metabolism. There were no changes in the ultrastructure or phospholipid biosynthesis of the islets after the drug treatment. These data indicate that cyclosporin A affects islets in culture, the clinical implications of which are so far difficult to assess. The inhibitory effect of cyclosporin A on islet cell DNA synthesis must nevertheless be considered in attempts to ameliorate Type 1 (insulin-dependent) diabetes, and when grating islet cells in numbers primarily insufficient to cure the recipient.

Effect of cigarette smoking upon the finger circulation in normal and diabetic subjects

The basal finger blood flow and the reaction to cigarette smoking was studied among diabetic patients with neuropathy and non-diabetic controls. Both the basal blood flow and the reaction to cigarette smoking were lower among diabetics. The diminution of the basal blood flow was believed to be secondary to the diabetic microangiopathy. The absence of vasoconstriction was attributed to a blockade of the neurologic mechanism involved. The site of the blockade remains open.