Baseline Findings of PreventE4: A Double-Blind Placebo Controlled Clinical Trial Testing High Dose DHA in APOE4 Carriers before the Onset of Dementia

INTRODUCTION

Lower blood levels of the omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) are correlated with worse cognitive functions, particularly among APOE ε4 carriers. Whether DHA supplementation in APOE ε4 carriers with limited DHA consumption and dementia risk factors can delay or slow down disease progression when started before the onset of clinical dementia is not known.

METHODS

PreventE4 is a double-blind, single site, randomized, placebo-controlled trial in cognitively unimpaired individuals with limited omega-3 consumption and dementia risk factors (n=368). Its objectives are to determine (1) whether carrying the APOE ε4 allele is associated with lower delivery of DHA to the brain; and (2) whether high dose DHA supplementation affects brain imaging biomarkers of AD and cognitive function.

RESULTS

365 cognitively unimpaired individuals between 55 and 80 (mean age 66) were randomized to 2 grams of DHA per day or identically appearing placebo for a period of 2 years. Half the participants were asked to complete lumbar punctures at baseline and 6-month visits to obtain cerebrospinal fluid (CSF). The primary trial outcome measure is the change in CSF DHA to arachidonic acid ratio after 6 months of the intervention (n=181). Secondary trial outcomes include the change in functional and structural connectivity using resting state functional MRI at 24 months (n=365). Exploratory outcomes include the change in Repeatable Battery of the Assessment of Neuropsychological Status at 24 months (n=365).

CONCLUSIONS

Findings from PreventE4 will clarify the brain delivery of DHA in individuals carrying the APOE ε4 allele with implications for dementia prevention strategies. Trial was registered as NCT03613844.

A functional genomics screen identifying blood cell development genes in Drosophila by undergraduates participating in a course-based research experience

Undergraduate students participating in the UCLA Undergraduate Research Consortium for Functional Genomics (URCFG) have conducted a two-phased screen using RNA interference (RNAi) in combination with fluorescent reporter proteins to identify genes important for hematopoiesis in Drosophila. This screen disrupted the function of approximately 3500 genes and identified 137 candidate genes for which loss of function leads to observable changes in the hematopoietic development. Targeting RNAi to maturing, progenitor, and regulatory cell types identified key subsets that either limit or promote blood cell maturation. Bioinformatic analysis reveals gene enrichment in several previously uncharacterized areas, including RNA processing and export and vesicular trafficking. Lastly, the participation of students in this course-based undergraduate research experience (CURE) correlated with increased learning gains across several areas, as well as increased STEM retention, indicating that authentic, student-driven research in the form of a CURE represents an impactful and enriching pedagogical approach.

Endovascular Treatment of Small and Very Small Intracranial Aneurysms with the Woven EndoBridge Device

BACKGROUND AND PURPOSE

The Woven EndoBridge has proved to be a safe and effective treatment, especially for wide-neck intracranial aneurysms. The recent fifth-generation Woven EndoBridge came with smaller devices. The purpose of this study was to assess the safety and efficiency of Woven EndoBridge treatment of small and very small aneurysms.

MATERIALS AND METHODS

Between September 2017 and March 2020, all consecutive patients treated with a 3- or 3.5 mm-width Woven EndoBridge device were included in this retrospective intention-to-treat study. Clinical and radiologic findings were evaluated at immediate and last-available follow-up. Angiographic outcome was assessed by an external expert reader.

RESULTS

One hundred twenty-eight aneurysms were treated with a fifth-generation Woven EndoBridge device including 29 with a width of ≤3.5 mm. Ten aneurysms were ruptured (34%). In 3 cases (10%), Woven EndoBridge treatment could not be performed because the aneurysm was still too small for the smallest available Woven EndoBridge device and another endovascular strategy was chosen. The median follow-up time was 11.2 months. Complete and adequate occlusion was obtained in 71% and 90% of the treated aneurysms, respectively. Retreatment was needed in 2 cases (10%). Symptomatic ischemic complications leading to transient neurologic deficits occurred in 2 cases (7%) (1 procedure-related and 1 device-related) but with full spontaneous recovery at discharge.

CONCLUSIONS

The fifth-generation Woven EndoBridge device seems to be a safe and technically feasible treatment for both ruptured and unruptured small and very small intracranial aneurysms, with satisfactory occlusion rates on midterm follow-up. However, further study is needed to evaluate longer-term efficiency.

Modeling the coating layer thickness in a pharmaceutical coating process

Although mechanistic numerical simulations can offer great insights into a process, they are limited with respect to resolved process time. While statistical models provide long-term predictability, determining the underlying probability distributions is often challenging. In this work, detailed CFD-DEM simulations of a pharmaceutical Wurster coating process for microspheres are used to evaluate the input parameters for a novel Monte-Carlo simulation approach. The combined strengths of both modeling approaches make it possible to predict the coating mass and thickness distributions over the entire process time. It was observed that smaller beads receive a thicker coating layer since they pass the spray zone closer to the nozzle. Moreover, it was established that, in contrast to the airflow rate, the spray rate has a great impact on the inter-particle coating variability. A stochastic model was developed to investigate the relative contribution of coating layer variability and fill weight variability to the product non-uniformity in a capsule filling process of Multiple Unit Pellet Systems (MUPS).

Effects of alirocumab on carotid plaque lipid content and inflammation: a time course study using serial vessel wall imaging

Background

PCSK9 inhibition has emerged as a potent pharmaceutical approach to lowering LDL cholesterol (LDL-C). Monoclonal anti-PCSK9 antibodies have been shown in recent clinical trials to reduce cardiovascular events in patients with atherosclerotic cardiovascular disease, but the underlying mechanisms are not fully understood. Meanwhile, circulatory inflammation markers were not reduced with PCSK9 inhibitors, thus their effects on plaque inflammation remain elusive. Vessel wall imaging with magnetic resonance (VW-MRI) has enabled serial monitoring of changes in carotid plaque lipid content and inflammation noninvasively that correlates with coronary and carotid vascular events.

Purpose

Using serial VW-MRI, we studied the effects and time course of PCSK9 inhibition with alirocumab on carotid plaque lipid content and inflammation.

Methods

Patients with LDL-C ≥70 mg/dl on ≤70 mg per week atorvastatin or an equivalent (due to statin intolerance or treating-physician discretion) and soft carotid plaque(s) identified on ultrasound underwent carotid VW-MRI. Those with confirmed lipid-rich plaque(s) on VW-MRI received alirocumab (150 mg subcutaneously every other week) and were re-scanned at 3, 6, and 12 months after treatment. Carotid VW-MRI included pre- and post-contrast images for measuring percent lipid-rich necrotic core volume (%LRNC) and dynamic contrast-enhanced images for measuring the extravasation rate of gadolinium contrast (Ktrans, reflecting tissue blood flow, endothelial surface area, and microvessel permeability), a marker of plaque inflammation. The co-primary endpoints were changes in %LRNC and Ktrans at 12 months from baseline.

Results

Of 31 patients enrolled, 27 completed the study (mean age: 69±9; male: 67%; on statins and/or ezetimibe: 41%; median LDL-C: 120 mg/dl [interquartile range: 99, 158]). Alirocumab induced a 59% reduction in LDL-C (p<0.001) on average at 3 months to a median of 54 mg/dl (interquartile range: 29, 69), which was maintained at later time points. From 9.8% at baseline, %LRNC was progressively reduced to 8.4% at 3 months, 7.5% at 6 months, and 7.2% at 12 months, representing a rapid 14% reduction (p=0.032) at 3 months and a total reduction of 20% (p=0.019) at 12 months. From 0.07±0.02 min-1 at baseline, Ktrans was not reduced at 3 or 6 months but was significantly reduced by 17% (p=0.029) at 12 months to 0.06±0.02 min-1. No significant changes in lumen or wall area were observed during the study period.

Conclusions

Serial VW-MRI documented plaque-stabilizing effects of PCSK9 inhibition with alirocumab, including plaque delipidation and attenuation of plaque inflammation. The reduction in plaque lipid content was apparent as early as 3 months. The reduction in Ktrans was not seen until 12 months of treatment and may indicate a later effect on microvascular structure and/or function. This observation represents the earliest time course of plaque morphology modification by non-statin therapy reported to date.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): The study was funded by an investigator-initiated grant from Regeneron and Sanofi.

Low plasma fibrinogen levels and blood product transfusion in liver transplantation

BACKGROUND

Risk of bleeding in liver transplantation is determined by surgical technique, preoperative hemoglobin and antifibrinolitic therapy. We hypothesized that keeping these confounders factors identical, preoperative plasma fibrinogen level of ≤2 g/L influenced on blood product requirements.

METHODS

Adult patients underwent orthotropic liver transplantation (LT) during the period between January 1998 and December 2009. Cases were selected according to a propensity matching analysis meeting the following criteria: surgical vena cava preservation, tranexamic acid administration and hemoglobin range between 90 to 120 g/L. Intraoperative management was protocolized. The main variable was the percentage of patients that did not require red blood cells (RBC's).

RESULTS

Six hundred sixty-four patients with LT, 208 excluded, 266 who cannot be matched, the analysis was performed on 190 patients. Two cohorts: Low fibrinogen (≤2 g/L) (61 cases) and standard fibrinogen (>2 g/L) (129 cases) were analyzed. Preoperative platelet count (73.5±52 vs. 104±65; 103/mm3) was different in contrast to the hemoglobin (104.2±8.6 vs. 105.6±8.3; g/L). Use of RBC's resulted significantly higher in the low fibrinogen group (median, 3 vs. 2). The number of patients with no blood product requirements was fewer in the low fibrinogen group (8 cases, 13% vs. 45 cases, 35%). The critical level of plasma fibrinogen (1 g/L) was reached after graft reperfusion in 7 cases (5.5%) in the standard fibrinogen group vs. 24 cases (39%) in the low fibrinogen group.

CONCLUSION

Our data suggest that preoperative plasma fibrinogen level of ≤2 g/L increases requirements for blood products during the surgical procedure of liver transplantation.

Coagulopathy management in liver transplantation

Risk of bleeding and transfusion in liver transplantation is determined by age, severity of liver disease, as well as hemoglobin and plasma fibrinogen values. During the hepatectomy and the anhepatic phase, the coagulopathy is related to a decrease in clotting factors caused by surgical bleeding, facilitated by the increased portal hypertension and esophageal-gastric venous distension. Corrections of hematologic disturbances by administration of large volumes of crystalloid, colloid, or blood products may worsen the coagulopathy. Also, impaired clearance of fibrinolytic enzymes released from damaged cells can lead to primary fibrinolysis. At time of graft reperfusion further deterioration may occur as characterized by global reduction among all coagulation factors, decreased plasminogen activator inhibitor factors, and simultaneous generation of tissue plasminogen activator. In situations with inherent risk of bleeding, hypofibrinogenemia must be corrected. Concern about unwanted events is a major limitation of preventive therapy. There is some evidence for the efficacy of antifibrinolytic drugs to reduce red blood cell requirements. A guide for antifibrinolytic therapy are clot firmness in trhomboelastometry or alternatively, diffuse bleeding associated to a fibrinogen value less than 1 g/L. Because thrombin generation is limited in severe thrombocytopenia, platelet administration is recommended when active bleeding coexists with a platelet count below 50,000/mm(3). When the administration of hemoderivates and antifibrinolytic drugs does not correct severe bleeding, consumption coagulopathy and secondary fibrinolysis should be suspected. Treatment of affected patients should be based upon correcting the underlying cause, mostly related to tissue hypoxia due to critical hypoperfusion.

Collaboration between HPMC and NaCMC in order to reach the polymer critical point in theophylline hydrophilic matrices

Percolation theory has been applied in order to study the existence of critical points as well as the possibility to find a “combined percolation threshold” for ternary hydrophilic matrices prepared with HPMC, NaCMC, and theophylline. For this purpose, different batches of ternary as well as binary hydrophilic matrices have been prepared. Critical points have been found for binary hydrophilic matrices between 21.5 and 31.3% (v/v) of HPMC and between 39 and 54% (v/v) of NaCMC, respectively. In a previous work carried out with the same polymers but a much more soluble drug (KCl), it was demonstrated the existence of a partial collaboration between the polymers in order to establish the gel layer. In this work, it has been observed for the first time the need of a minimum concentration of one of the matrix-forming polymer (between 10 and 20% v/v, approximately) for establishing an effective collaboration.

Alloantigen-specific response is preserved and autoimmunity is maintained in an HIV-positive patient with immunoglobulin A nephropathy undergoing renal transplantation: a warning about long-term reduction in immunosuppression--a case report

We report the case of a 43-year-old patient with HIV infection treated with antiretroviral therapy, which was complicated by immunoglobulin A (IgA) nephropathy and renal failure, who subsequently was transplanted using a deceased donor kidney transplant. During the late posttransplant period we detected specific anti-donor HLA antibodies showing a preserved alloantigen response. A renal biopsy showed no acute cellular or humoral rejection, an absence of pericapillary C4d deposits or SV40 infected cells, but demonstrated IgA mesangial deposits and mild interstitial fibrosis probably related to calcineurin inhibitor toxicity. This case shows that allo- and autoimmune responses are preserved despite immunosuppressive treatment and original HIV disease. It warns of the importance of maintaining optimal monitoring and immunosuppressive strategies among HIV-positive recipients who become solid organ transplant recipients.

Evaluation of late immunologic parameters among renal transplant recipients induced with Campath-1H

Organ transplantation success depends principally on avoiding rejection, a purpose almost accomplished with immunosuppressant therapy. Nevertheless, drug side effects have promoted the search for other mechanisms to restrain alloresponses. T-regulatory cells (Treg) might exert that function. Campath 1H (C1H) induces Treg proliferation in the period subsequent to T-cell depletion following C1H administration. In the present study, the status of Treg and de novo HLA antibody production was determined posttransplantation when T-cell repopulation had been completed. In 14 patients, the following parameters were analyzed: renal function, rejection, Treg, panel-reactive antibody (PRA), and HLA antibodies. Patient and graft survivals were 100%. At the moment of Treg determination (20 months following transplant) the mean tacrolimus level was 8.4 ng/mL. One patient experienced an antibody-mediated rejection at 15 months after transplantation while having 3.2% Treg, with excellent treatment responses. Mean leukocyte and lymphocyte counts were 5752 and 1183 cells/mm(3); the mean peripheral blood percentage of Treg of 7.1% +/- 5.9% was not different from that observed in subjects without induction (mean 5.5% +/- 2.5%). Three patients (21%) showed Treg greater than 8.0%. In seven patients, we compared Treg at 4 and 20 months posttransplant, observing a decline from a mean of 19.9% to 5.9% (P = .05). In seven recipients, posttransplant PRA was determined; five of them became "de novo" sensitized, three with a mean class I PRA of 16% and two with a mean class II PRA of 37%. In conclusion, patient and graft survivals were excellent, mean Treg percentage was not elevated with results lower than in the early posttransplant period. Rejection incidence was negligible. Late "de novo" sensitization occurred in 70% showing that B cell-mediated alloresponses were only partially controlled among recipients induced with C1H even when associated with sustained anticalcineurin treatment.

Alemtuzumab induction in kidney transplantation: clinical results and impact on T-regulatory cells

Alemtuzumab (ALT), a humanized monoclonal anti-CD52 antibody, was introduced in solid organ transplantation as an induction agent. ALT associated with anticalcineurins has provided a low incidence of acute rejection episodes (ARE) and potential tolerogenic properties. We analyzed the clinical outcomes and effects on peripheral Treg of renal transplant recipients treated with ALT. Six-month data on kidney alone or kidney combined with pancreas or liver patients treated with ALT and tacrolimus (TAC) in standard doses were compared with those on renal transplant recipients of similar demography who were not treated with ALT. We evaluated patient and graft survivals, ARE incidence, hematological parameters, renal function, adverse events, and CD4+CD25+FoxP3+ T cells in peripheral blood. Demographics of recipients, donors, and transplants were similar in both groups. Mean HLA mismatch was slightly greater among ALT-treated patients (3.5 vs 2.5). No combined transplantation was performed in the ALT-untreated group. Patient and graft survivals were 100% without rejection or serious infections in both groups. ALT-treated recipients showed anemia and leukopenia in 3 patients as well as severe lymphopenia in 5 recipients, who partially recovered on day 90. Final mean plasma creatinine was 1.4 mg/dL, while calculated creatinine clearance was approximately 65 mL/min in both groups. Mean Treg cell percentage was higher among ALT-treated recipients than the comparative group or healthy controls (P < .05). In conclusion, renal transplantation results obtained using ALT with rigorous immunosuppressive therapy were excellent; serious adverse events and acute rejection were absent. The effect of the increased proportion of Treg cells must be evaluated with longer observation.

Conversion from a calcineurin inhibitor-based immunosuppressive regimen to everolimus in renal transplant recipients: effect on renal function and proteinuria

New immunosuppressive agents are being actively researched to avoid complications of chronic allograft nephropathy (CAN), calcineurin inhibitor (CNI) nephrotoxicity, and posttransplantation cancer. The family of mTOR inhibitors offers a unique immunosuppressive opportunity to avoid CNI toxicity and reduce the incidence of malignancy. Nevertheless, increasing data have demonstrated that sirolimus (SRL), the first mTOR introduced in the treatment of solid organ transplant recipients, induces proteinuria, an adverse event that could produce deterioration of long-term renal function. In this short-term study of patients followed for 1 to 16 months, we examined changes in renal function and proteinuria among renal transplant recipients converted from a CNI-based regimen to an everolimus (EVL)-based one, a recently introduced mTOR inhibitor. Our data showed that renal function can be optimized after conversion to EVL by up to 42% in recipients showing CAN grade 1 or 2, or CNI nephrotoxicity. Importantly, patients who improved their creatinine clearance did not show increased proteinuria measured in a voided specimen as the ratio of urinary protein and creatinine concentration (P/C). These results, if confirmed with long-term follow-up and a larger number of patients, would allow us to consider EVL as a promising agent for maintenance immunosuppressive regimens in kidney transplantation.

Conversion from a calcineurin inhibitor-based immunosuppressive regimen to everolimus in renal transplant recipients: effect on renal function and proteinuria

New immunosuppressive agents are being actively researched to avoid complications of chronic allograft nephropathy (CAN), calcineurin inhibitor (CNI) nephrotoxicity, and posttransplantation cancer. The family of mTOR inhibitors offers a unique immunosuppressive opportunity to avoid CNI toxicity and reduce the incidence of malignancy. Nevertheless, increasing data have demonstrated that sirolimus (SRL), the first mTOR introduced in the treatment of solid organ transplant recipients, induces proteinuria, an adverse event that could produce deterioration of long-term renal function. In this short-term study of patients followed for 1 to 16 months, we examined changes in renal function and proteinuria among renal transplant recipients converted from a CNI-based regimen to an everolimus (EVL)-based one, a recently introduced mTOR inhibitor. Our data showed that renal function can be optimized after conversion to EVL by up to 42% in recipients showing CAN grade 1 or 2, or CNI nephrotoxicity. Importantly, patients who improved their creatinine clearance did not show increased proteinuria measured in a voided specimen as the ratio of urinary protein and creatinine concentration (P/C). These results, if confirmed with long-term follow-up and a larger number of patients, would allow us to consider EVL as a promising agent for maintenance immunosuppressive regimens in kidney transplantation.

Development of an HPLC method for determination of diphenidol in plasma and its application in an oral multi-dose bioequivalence study in a healthy female mexican population

Diphenidol was determined by an HPLC method developed in our laboratory. It was validated and proved to be linear in the 40-400 ng/ml range. Accuracy for quality-control samples for intra and inter day assays ranged from 96.1-98.9% and 98.8-101.4%, respectively. This method was applied to a multi-dose bioequivalence study. No serious side effects were observed in the multi-dose design. Pharmacokinetic parameters (mean+/-standard error [S.E.]) of Cavg (ng/ml) and AUCtau (ngh/ml) for reference and test products were 139.54+/-12.66 versus 148.60+/-16.51 and 551.07+/-53.53 versus 588.78+/-69.02, respectively. Log-transformed values were compared by analysis of variance (ANOVA) followed by the classical 90% confidence interval (CI 90%) test and Schuirmann's test. Confidence limits ranged from 91.48-116.18% for Cmax and from 91.24-117.65% for AUCtau. These results suggest that the analytical method was linear, precise, and accurate for our purpose, and that both assayed formulations were bioequivalent.

Bioequivalence evaluation of two brands of ketoconazole tablets (Onofin-K and Nizoral) in a healthy female Mexican population

A randomized, crossover study was conducted in 24 healthy female volunteers to compare the bioavailability of two brands of ketoconazole (200 mg) tablets; Onofin-K (Farmacéuticos Rayere S.A., Mexico) as the test and Nizoral (Janssen-Cilag, Mexico) as the reference products. The study was performed at the Clinical Pharmacology Research Center of the Hospital General de Mexico in Mexico City. Two tablets (400 mg) were administered as a single dose with 250 ml of water after a 12 h overnight fast on two treatment days separated by a 1 week washout period. After dosing, serial blood samples were collected for a period of 12 h. Plasma harvested was analysed for ketoconazole by a modified and validated HPLC method with UV detection in the range 400-14000 ng/ml, using 200 microl of plasma in a full-run time of 2.5 min. The pharmacokinetic parameters AUC(0-t), AUC(0-alpha), Cmax, Tmax and t(1/2) were determined from plasma concentrations of both formulations and the results discussed. AUC(0-t), AUC(0-alpha) and Cmax were tested for bioequivalence after log transformation of data, and no significant differences were found either in 90% classic confidence interval or in the Anderson and Hauck test (p < 0.05). Based on statistical analysis, it is concluded that Onofin-K is bioequivalent to Nizoral.

Bioequivalence evaluation of two brands of meloxicam tablets (promotion® and mobicox®): pharmacokinetics in a healthy female Mexican population

We conducted a randomized, crossover study in 23 healthy young female volunteers to compare the bioavailability of two brands of meloxicam (7.5 mg) tablets and to obtain pharmacokinetic parameters of this molecule in Mexican population not reported previously. Two tablets (15 mg) were administered as a single dose on 2 treatment days separated by a 1-week washout period. After dosing, serial blood samples were collected for a period of 72 h. Plasma harvested was analyzed for meloxicam by a modified and validated high-performance liquid chromatography (HPLC) method previously reported. Pharmacokinetic parameters AUC(0-t), AUC(0-alpha), C(max), T(max), k(e), MRT and t(1/2) were determined from plasma concentrations of both formulations, resulting in a C(max) 120% larger than and a T(max) 65% faster than those reported in other populations. AUC(0-t), AUC(0-alpha), and C(max) were statistically tested for bioequivalence after log transformation data in a non-balanced design, and no significant differences were found either in 90% classical confidence interval (90% CI) or in Schuirmann test (p < 0.05); thus, we concluded that bioequivalence existed between both formulations.

[Comparison of the efficacy of intraarticular and intraarterial injections of two betamethasone preparations in patients with osteoarthritis or epicondilytis]

BACKGROUND

Local infiltration with corticoids is a simple therapy for rheumatic disorders devoid of systemic adverse reactions.

AIM

To compare the efficacy of two betametasone preparations from two different pharmaceutical laboratories in the treatment of patients with osteoarthritis or epicondylitis.

PATIENTS AND METHODS

Fourty patients with knee osteoarthritis and 12 patients with epicondylitis were studied. Using a double blind protocol, one of the two betametasone preparations was used for local infiltration of the lesions. The change in a global score of clinical variables including pain and disability was assessed after 30 days of the infiltration.

RESULTS

In patients with osteoarthritis, the global score decreased significantly with both preparations, but no differences were observed between preparations (7.3 +/- 1.8 to 3.9 +/- 2.3 with preparation A and 7.8 +/- 1.9 to 3.6 +/- 2.3 with preparation B). In patients with epicondylitis, pain was also significantly reduced but no differences between preparations was observed (7 +/- 2.1 to 1.4 +/- 2.5 for preparation A and 4.6 +/- 2.8 to 1.2 +/- 1.6 for preparation B).

CONCLUSIONS

Local infiltration with both betametasone preparations was equally effective in the treatment of patients with knee osteoarthritis or epicondilytis.

Coating PTFE vascular prostheses with a fibroblastic matrix improves cell retention when subjected to blood flow

An investigation was made into the effect of blood flow on endothelial cells (EC) and mesothelial cells (MC) seeded on a vascular expanded polytetrafluoroethylene (ePTFE) prosthesis coated with a fibroblastic matrix. Endothelial cells were obtained from the external jugular vein and MC from the omentum. To test the performance of prostheses, a custom designed, femoral "ex vivo" circuit was developed in mongrel dogs. Four study groups were established: a control group, A1, where prostheses were uncoated and seeded with EC; a second control group, A2, where prostheses were uncoated and seeded with MC; group B1 where prostheses were coated with a fibroblastic matrix and seeded with EC; and group B2 where coated prostheses were seeded with MC. All cells were labeled with 111Indium oxine (10 microCi/mL) before seeding. After the seeded cells had formed a monolayer on the ePTFE prostheses (which took approximately 24 h) the prostheses were placed in the "ex vivo" circuit. The rates of blood flow to which prostheses were exposed were measured at the point of inflow (117.5 +/- 12.50 mL/min, mean +/- SD) and outflow (72.6 +/- 14.3 mL/min). MC showed a greater baseline radionuclide uptake than did EC. The cells of groups B1 and B2 adhered sufficiently to the fibroblastic matrix and covered enough of the prosthetic surface to be positioned in the "ex vivo" circuit (76.90 +/- 8.24% surface covered in EC-seeded prostheses and 71.65 +/- 6.23% in MC-seeded prostheses). After exposure to blood flow the quantity of radionuclide-labeled cells and the prosthetic surface covered by them were greatly reduced though the fibroblast-coated prostheses showed greater cell retention.

[Twelve-year trends of hip fracture rates in Chile. Is there a relationship between their increase and population aging?]

BACKGROUND

Epidemiology of osteoporosis is assessed measuring bone density or measuring the rates of bone frailty-related fracture rates. Of these, the most important are hip fractures, that markedly increase after 65 years of age.

AIM

To measure the incidence of hip fractures in Chile from 1982 to 1993.

MATERIAL AND METHODS

All hospital discharges that occurred in Chile from 1982 to 1993 were analyzed, looking for the diagnosis of hip fracture. National censuses in the same period were also analyzed searching for possible changes in the age structure of the population. Fracture rates were analyzed for three age groups, and changes along the years were calculated correlating the rates with the number of the year.

RESULTS

In the twelve year period, women aged 55-64 years old had a correlation of 0.32 (NS), women aged 65-74 years old had a correlation of 0.58 (NS) and women aged over 75 years old had a correlation of 0.95 (p < 0.001). This age group corresponded to 2.01% of the whole population in 1982 and to 2.52% in 1993. The mean age of the group increased from 80.7 to 80.9 years in the same lapse.

CONCLUSIONS

Fracture rates increased in the 12 years period studied, specially among women older than 75 years old. During the same period the proportion of people over 75 years old also increased, but there was only a slight increase in its mean age. Thus, the increase in fracture rates is disproportionate to population aging and could be related to changes in lifestyles.

Mesothelial versus endothelial cell seeding: evaluation of cell adherence to a fibroblastic matrix using 111In oxine

OBJECTIVES

The aim of this study was to compare the behaviour of mesothelial cells (MC) to that of endothelial cells (EC) when seeded onto a PTFE, prosthesis coated with a fibroblastic matrix.

DESIGN, MATERIAL AND METHODS

Three study groups were examined: a control group (Control) of PTFE prostheses with a fibroblast matrix (n = 8); Group EC, PTFE prostheses seeded with EC on a fibroblastic matrix (n = 8); and Group MC, PTFE, prostheses seeded with MC on a fibroblastic matrix (n = 8). All cell types were labelled with 111In (100 microCi/ml) 24 h after seeding, when the cells had formed a monolayer on the prosthetic surface. Radioactive levels were measured at 2, 4, 6, and 24 h.

RESULTS

Both EC and MC showed optimal adherence. The MC had a better radioactive uptake and retention than the EC. The number of EC and MC cells that remained adherent to the matrix was large enough to ensure complete covering of the prosthetic surface.

CONCLUSION

The use of MC is therefore feasible as an optimal alternative for achieving a natural covering on vascular prostheses prepared with a fibroblastic matrix.

[Patients with rheumatoid arthritis: study of the correlation between density of glucocorticoid receptors in synovial cells and clinical response to steroidal treatment]

BACKGROUND

The target cellular response to glucocorticoids is proportional to the concentrations or affinity of specific receptors to these substances.

AIM

To look for a correlation between glucocorticoid receptor concentrations in synovial wall cells and the clinical response to steroidal treatment in patients with rheumatoid arthritis.

PATIENTS AND METHODS

Twenty eight patients with rheumatoid arthritis were studied. Each subject was subjected to a synovial biopsy, in which a dry radioautographic technique for diffusible compounds was used. Patients were treated afterwards with three 500 mg intravenous pulses of methilprednisolone.

RESULTS

A mean of 44.8% of synovial cells (range 30.1-62.8%) had binding sites for 3H dexamethasone. All patients had a significant clinical improvement after methylprednisolone. Multiple regression analysis did not show a correlation between clinical response and glucocorticoid receptor concentration.

CONCLUSIONS

The lack of association between glucocorticoid receptor concentrations and clinical response could be due to the large steroid dose used, that saturated all available receptors.

Atherogenic effects of cyclosporine in an experimental model of arterial autograft

One of the effects attributed to CsA is a possible acceleration of atherogenic processes, which contributes to the failure of transplanted organs. This study was undertaken to evaluate the effect of CsA and two vehicles, cremophor and ethanol, in an experimental model of arterial autograft in the rat. Female Sprague-Dawley rats were distributed into 3 study groups: Group 1 (control) had an arterial autograft in the common iliac artery without pretreatment; group 2 (CsA-cremophor) animals were pretreated with a daily dose of CsA (5 mg/kg, Sandimmun) for 4 days before the autograft was made; and group 3 (CsA-ethanol + Tween) animals were pretreated for 4 days before implantation of the autograft with CsA in a vehicle of ethanol + Tween at the same dose as used in group 2 (5 mg/kg). The study periods were 7, 14, 21, 30, and 50 postoperative days. Studies were made by optical microscopy, transmission electron microscopy, scanning electron microscopy, and autoradiography. Evaluation of the results showed that in the control group the postoperative repair process lead to formation of an intimal neolayer throughout the entire surgical zone, with scant participation of white cells. Group 2 (CsA-cremophor) had a marked increase in luminal thrombogenicity, important adhesion and infiltration of white cells, loss of smooth muscle cells in the medial layer, and atherogenic degeneration of the medial layer. The generation of the neointimal layer is delayed by 2 weeks with respect to the control group. However, once the neointimal begins to form, its thickness increases rapidly, reaching values similar to those seen in the control group at 50 days. The myointima also shows atherogenic characteristics, such as monocyte-macrophage infiltration and dystrophic calcification. In group 3 (CsA-ethanol+Tween, that is, CsA in a nonoleaginous vehicle), the effects were similar to those seen in group 2 (CsA-cremophor), with a reduction in the presence of lipid-laden cells in the medial layer. Based on these observations, we conclude that CsA per se induced atherogenic changes in the repair process of the arterial lesion that were independent of the vehicle of administration. CsA delayed, but did not inhibit, formation of a myointima and the myointima formed exhibited atherogenic characteristics. The most important effects were noted in the medial layer, which experienced intense degeneration.

[Fine needle aspiration biopsy of thyroid nodules. Analysis of results obtained using a new method with histological examination of the sample]

Fine needle aspiration biopsy (FNAB) is the most useful preoperative work up method for patients with nodular goiter. We analyze 173 patients that underwent FNAB and were subsequently operated. The sample with FNAB was processed both for cytological and histological study, using methods developed at the hospital. The preoperative diagnosis reached was compared with that obtained with the surgical piece. Results showed that the histological analysis of the FNAB sample improved the sensitivity of the method, when compared with the cytological study, from 68.5% to 87.8% (p < 0.035) without modifying specificity (100% for both methods). It is concluded that FNAB with histological study of the sample has a high diagnostic yield and is exempt of complications.

Assessment of cyclosporine A-induced ultrastructural changes in vascular wall using an experimental arterial autograft model

The objective of this ultrastructural study was to assess the effects of cyclosporine A (CsA) in an experimental model of arterial autograft. Fifty female Sprague-Dawley rats weighing 250-300 g were employed. Using a microsurgical technique, an arterial autograft measuring approximately 5 mm in length was placed in the right common iliac artery. Two groups were established: group I (control), consisting of 25 animals subjected only to arterial autograft; and group II (pre- and postoperative CsA), also consisting of 25 animals which received a daily subcutaneous dose of 5 mg/kg CsA (Sandimmun, Sandoz) on the four days preceding the surgery and thereafter, until sacrifice. The animals were sacrificed on postoperative day 7, 14, 21, 30 and 50. The specimens (autografts) obtained were studied under transmission and scanning electron microscopes. In the control group, the process of endothelialization of the graft was completed by day 14. In the CsA-treated group, restoration of the endothelium took 50 days. The development of intimal hyperplasia was delayed in the treated group. There were no morphological changes in its structure when compared to the control group. The tunica media had thinned in the treated grafts, with loss of smooth muscle cells, fragmentation and lysis of the elastic lamina, presence of lipid-filled macrophages, and muscle cells with cytoplasmic lipid vacuoles. In our opinion, these results suggest that the action of CsA mainly targets on the endothelium and smooth muscle cells, exerting a toxic effect in an in vivo arterial graft model.

Slowing proliferation in head and neck tumors: in vitro growth inhibitory effects of the polyamine analog BE-4-4-4-4 in human squamous cell carcinomas

PURPOSE

These preclinical studies were carried out to examine the potential of the antiproliferative polyamine analog 1,19-bis-(ethylamino)-5,10,15-triazanonadecane (BE-4-4-4-4) to serve as a therapy adjuvant to radiation for patients with rapidly dividing tumors of the head and neck (H&N).

METHODS AND MATERIALS

Cytostatic and cytotoxic effects of this polyamine analog were investigated in three squamous cell carcinoma (SCC) cell lines derived from human H&N tumors.

RESULTS

Growth inhibition was achieved in all cell lines within 3-4 days of continuous 10 microM drug exposure, and inhibition of cell cycle proliferation kinetics was confirmed via flow cytometry. Cytotoxicity was pronounced (3-4 log cell kill) in the SCC-38 and SCC-4Y cell lines with continuous 10 microM analog exposure over 5 days, and was minimal in the SCC-13Y cell line. No demonstrable effect of BE-4-4-4-4 on single dose radiation survival was identified in any SCC cell line. Ornithine decarboxylase (ODC) activity was rapidly inhibited (1-2 h) following 10 microM BE-4-4-4-4 exposure in all SCC cell lines (approximately 90%), whereas identical exposure to 10 microM difluoromethylornithine (DFMO) induced animal ODC inhibition (approximately 10%). Dose-dependent depletion of endogenous polyamines (putrescine, spermidine, spermine) was achieved in all SCC cell lines following 1 microM and 10 microM BE-4-4-4-4 exposures. Difluoromethylornithine was significantly less potent than BE-4-4-4-4 in its capacity to deplete endogenous polyamines, with no measureable depletion of spermine pools even with 5 mM x 48 h DFMO exposures.

CONCLUSIONS

These data evaluate cytostatic and cytotoxic properties of the polyamine analog BE-4-4-4-4 in human SCCs, and suggest a role for investigation of such agents as an adjuvant to radiation in the therapeutic approach to rapidly dividing human tumors such as those that occur in the H&N.

Integration of biomaterials implanted into abdominal wall: process of scar formation and macrophage response

The behaviour of two biomaterials polytetrafluoroethylene (PTFE) and polypropylene (PL) has been studied, focussing especially on the macrophage response to the implant, as well as on certain aspects of the process of scar formation. A total of 24 animals (white New Zealand rabbits) received prostheses implanted into the anterior abdominal wall in such a way as to involve every layer over an area of 7 cm x 5 cm. The interfaces formed with the visceral peritoneum, subcutaneous tissue layer and the recipient muscle-aponeurotic tissue were assessed. The techniques employed were light microscopy, scanning electron microscopy and immunohistochemical methods, the latter using a monoclonal antibody specific for rabbit macrophages (RAM-11). From the results obtained, it can be seen that: (a) the structure of PL allows its total integration with the reparative tissue, while PTFE becomes encapsulated, on both the subcutaneous and the peritoneal aspects, by orderly connective tissue; (b) the macrophage response, determined on the basis of the presence of labelled macrophages, shows a similar pattern in both biomaterials; and (c) angiogenesis is very intense in the PL mesh, whereas the PTFE prosthesis undergoes almost no vascular colonization.

[Comparison of 2 treatment schemes to eradicate Helicobacter pylori]

INTRODUCTION

Anti secretory drugs, antimicrobials and bismuth salts are used with variable success to eradicate Helicobacter pylori.

AIM

To assess the effectiveness and rates of reinfection of two therapeutic modalities H pylori infection in adult patients with duodenal ulcer or non ulcer dyspepsia.

METHODS

During upper gastrointestinal endoscopy, 5 antral and 2 fundic biopsies were obtained and sent for microbiological and anatomopathological study. Patients infected with Helicobacter pylori were randomly assigned to receive during two weeks omeprazole 20 mg od plus amoxicillin 500 mg tid (group A) or bismuth subsalicylate 260 mg bid, metronidazole 250 mg tid and amoxicillin 500 mg tid (group B). A new endoscopy with antral and fundic biopsies was performed to all patients four weeks after discontinuing treatment and six months later to those in whom H pylori was eradicated.

RESULTS

Eighty patients (40 in each treatment group) completed the treatment and follow up. H pylori was eradicated in 22 patients of group A (55%) and 28 of group B (70%). Minor adverse effects were reported by 5 patients in group A (12%) and 11 in group B (27.5%). Six months later, reinfection was documented in 12 patients of group A and 8 of group B (54% and 30% of those with successful treatment respectively). Ten of twenty five patients with duodenal ulcer had reinfections, but there was only one ulcer relapse.

CONCLUSIONS

These two treatment modalities have similar results.

[Treatment of pediculosis capitis in children with permethrin 1% shampoo or lotion]

A clinical and entomological trial was carried out in 88 head louse (Pediculus humanus capitis) infested children treated with a single dose of 1% permethrin shampoo or lotion. The sex distribution was 47 males an 41 females with ages ranging between 5 and 14 year olds. In order to assess the efficiency of treatments, search for adult forms, nymphs and eggs (nits) of the parasite was performed in each of the children, before and after treatment (30 minutes, 7 days and 21 days). The entomological evaluations consisted in stereoscopic and microscopic examinations of a mean of 12 hair samples taken from the retroauricular and occipital regions of each of the children, the biological condition of eggs, viable (immature, mature), dead and empty, was recorded. The cure rates--both clinical and entomological--obtained were 91.5% for shampoo and 95.2% for lotion. No adverse reactions with the two formulations used were reported. In conclusion, 1% permethrin shampoo or lotion in an effective and safe treatment for pediculosis capitis.

[Non ulcerative dyspepsia: relationship of symptomatology, gastritis and Helicobacter pylori]

BACKGROUND

histological alterations of gastric mucosa and its colonization by Helicobacter pylori are postuled to be implicated in the pathogenesis of non ulcer dyspepsia.

AIM

to study the possible relationships between histological gastritis and Helicobacter pylori in non ulcer dyspepsia symptomatology.

PATIENTS AND METHODS

fifty four patients (39 females) with non ulcer dyspepsia whose ages ranged from 17 to 68 years were subjected to an upper GI endoscopy with gastric mucosa biopsy samples for histological study and microbiological identification of Helicobacter pylori. Gastrointestinal complains were blindly quantified using a scored questionnaire.

RESULTS

thirty one subjects (57.4%) had Helicobacter pylori in their gastric mucosa. There was acute inflammatory activity in 26 of the 31 patients with Helicobacter pylori (81%) and 15 of 23 without Helicobacter (65%). The median score of symptoms was 7 (range 2-13) in patients with Helicobacter and 6 (range 2-10) in patients without Helicobacter.

CONCLUSIONS

there were no significant differences in gastric mucosa acute inflammatory activity and non ulcer dyspepsia symptomatology between patients with or without Helicobacter pylori colonization of gastric mucosa.

Combining polyamine depletion with radiation therapy for rapidly dividing head and neck tumors: strategies for improved locoregional control

PURPOSE

Locoregional control is adversely affected as clonogens from rapidly proliferating tumors repopulate during a course of radiation therapy. The cytostatic agent alpha-difluoromethylornithine (DFMO) was investigated for its capacity to slow proliferation kinetics in human squamous cell carcinomas (SCC) of the head and neck (H&N), with the ultimate objective of improving locoregional control in rapidly dividing tumors treated with radiation therapy.

METHODS AND MATERIALS

Three human SCC cell lines established from primary H&N tumors were evaluated in vitro (cell culture) and in vivo (SCC tumor xenografts in athymic mice) for the capacity of DFMO to induce growth inhibition. Flow cytometry analysis of SCC tumor growth kinetics and quantitative assessment of polyamine biosynthesis inhibition was performed to verify DFMO activity. DFMO effects on in vitro SCC radiosensitivity using clonogenic survival were also studied.

RESULTS

A noncytotoxic exposure to DFMO (5mM x 72 hours) induced pronounced growth inhibition in all three SCC cell lines (70-90% at 7 days), and induced a 2-3 fold delay in volume doubling time for SCC tumor xenografts when administered orally in the drinking water (1.5%) to athymic mice. Kinetic analysis via flow cytometry confirmed that DFMO produced a lengthening of SCC cell cycle times, but did not alter in vitro radiosensitivity. Inhibition of ornithine decarboxylase (ODC) activity and depletion of endogenous polyamines (putrescine and spermidine), were confirmed in normal tissue (mouse skin) and in human SCC tumor xenografts of athymic mice receiving continuous oral DFMO.

CONCLUSION

These data indicate that antiproliferative agents, such as DFMO, are capable of altering human SCC growth kinetics without altering intrinsic radiosensitivity. Such kinetic modulation may therefore provide a strategy to reduce the adverse impact of tumor cell proliferation during a radiotherapy treatment course for rapidly dividing tumors such as those in the H&N.

Macrophage response to experimental implantation of polypropylene prostheses

We have assessed the macrophage response to polypropylene mesh (Marlex) implanted into the abdominal wall of New Zealand white rabbits, using RAM-11, a monoclonal antibody specific for rabbit macrophages. The response diminishes during the course of the first 90 days after implantation, although the presence of other cell types typical of foreign-body reactions increases. We have also confirmed the high degree of integration of the biomaterial into the wall achieved after 9 weeks. This has been determined using light and scanning electron microscopy. Likewise, we have observed the formation of numerous adhesions between the polypropylene mesh and the viscera of the abdominal cavity.

[Breast biopsy with fine needle. Evaluation of a new method]

A new methodology to obtain tissue samples from breast tumors through fine needle aspiration is described. This consists of a screwdriver like movement of the needle and continuous aspiration. The tissue is embedded in a blood clot, fixed in 10% formalin and routinely processed for histopathological study. From March 1987 to March 1990 this technique was applied in 84 patients. Ten did not have conventional histopathological study. The 74 patients studied had 76 tumors. Six cases (7.9%) had "unsatisfactory" specimens and nine (11.8%) only allowed cytological diagnosis. The 61 remaining samples (80.3%) were considered "sufficient" for histopathological study. The new methodology had a sensitivity of 95.5% specificity of 100% and positive predictive value of 100%. In this series there were no false positive cases.

Modulation of proliferation kinetics in human squamous cell carcinomas of the head and neck

OBJECTIVE

Proliferation of tumor clonogens during a course of conventional head and neck radiotherapy serves to compromise ultimate tumor control. Biologic strategies that attempt to alter tumor proliferation kinetics using cytostatic or antiproliferative agents may therefore prove valuable by limiting tumor cell repopulation during therapy.

DESIGN

Three human squamous cell carcinoma (SCC) cell lines, derived from primary head and neck cancers, have been characterized in vitro via flow cytometric analysis of proliferation kinetics, and in vivo via tumor xenograft growth evaluation in athymic mice.

RESULTS

The antiproliferative agent alpha-difluoromethylornithine (DFMO), an inhibitor of polyamine biosynthesis, induced growth inhibition of these SCCs in culture and when administered orally to athymic mice harboring SCC tumor xenografts. Cell cycle kinetic analysis via flow cytometry revealed that DFMO induced a lengthening of in vitro tumor cell potential doubling times. Similarly, DFMO administered continuously via the drinking water to athymic mice harboring human SCC xenografts induced a prolongation of in vivo tumor volume doubling.

CONCLUSIONS

These data indicate that biologic agents, such as DFMO, can alter SCC growth kinetics and may prove useful in designing new therapeutic strategies for rapidly proliferating tumors such as those that occur in the head and neck.

Restoration of malonyl-CoA sensitivity of soluble rat liver mitochondria carnitine palmitoyltransferase by reconstitution with a partially purified malonyl-CoA binding protein

Solubilization of rat liver mitochondria in 5% Triton X-100 followed by chromatography on a hydroxylapatite column resulted in the identification of malonyl-CoA binding protein(s) distinct from a major carnitine palmitoyltransferase activity peak. Further purification of the malonyl-CoA binding protein(s) on an acyl-CoA affinity column followed by sodium dodecyl sulfate gel electrophoresis indicated proteins with Mr mass of 90 and 45-33 kDa. A purified liver malonyl-CoA binding fraction, which was devoid of carnitine palmitoyltransferase, and a soluble malonyl-CoA-insensitive carnitine palmitoyltransferase were reconstituted by dialysis in a liposome system. The enzyme activity in the reconstituted system was decreased by 50% in the presence of 100 microM malonyl-CoA. Rat liver mitochondria carnitine palmitoyltransferase may be composed of an easily dissociable catalytic unit and a malonyl-CoA sensitivity conferring regulatory component.

[Tracheoesophageal fistula secondary to ingestion of a button battery]

An eleven month old girl was admitted to a county hospital because of persistent low grade fever, cough, vomitus and food and oral fluids rejection. A small radiopaque, button sized, round object was seen impacted in the upper esophageal third on X ray examination and later extracted by endoscopy, corresponding to an electric cell, from a father's handwatch, which had been ingested by the baby without knowledge of parents about 30 h before. After 12 h fasting, oral feedings were resumed being apparently well tolerated, but in the following day fever and respiratory distress reappeared, together with drooling, cianosis, abdominal distention and pale skin. Patient was transferred to a regional hospital where extensive bilateral pneumonia and anemia were documented. Gastric drainage via nasogastric tube, antibiotic treatment, blood transfusion and oxygen therapy were given from admission, but she died within a few hours. At necropsy a 3 per 2.5 cm diameter orifice of sharp borders was seen in the upper third of the esophagus, communicating to tracheal lumen through its upper six cartilages. Extensive, severe, bilateral pneumonia was confirmed. When this kind of electric cells become impacted into the esophagus, wall necrosis may occur within 4 h and perforation within 8 to 12 h and can be prevented by immediate endoscopic extraction. Otherwise fistulae should be suspected and patients managed accordingly. Emergency room medical staff must always be aware of this potentially lethal condition and its proper management. Infants should not be permitted to play with such apparently innocent objects as battery operated handwatches.

[Neurologic involvement in Reiter's disease. Report of 2 cases]

Neurologic involvements is a rare complication of Reiter syndrome. It may precede other manifestations and constitutes a cause of death. We report 2 cases. The first, an 18 year-old male developed arthritis, fever, balanitis and sacroileitis 2 months after non gonococcal urethritis. He received phenylbutazone and local steroids without improvement. Logic dysphagia, diplopia with bilateral paralysis of the IV and VI cranial nerves and generalized absent reflexes developed gradually 2 weeks after admission. Methylprednisolone pulses failed to improve the patient's condition and plasmapheresis was associated to near complete remission after 6 exchanges. The other patient, a 31 year old male started out with alternating lower extremity paresis. One month later, urethritis, conjunctivitis, arthritis and sacroileitis appeared. The electromyogram was characteristic of axon sensorimotor polyneuropathy. Administration of naproxen was associated to complete improvement within 2 weeks. Neither patient had shown evidence of recurrence after a 5 year follow up period.

[Epidemiology of fractures in Chile]

Bone fractures represented 3.3% of diagnosis among 1,003,267 patients discharged from National Health System Hospitals in Chile during 1985. Among 73,534 certified deaths, 1.2% followed fractures. Significantly higher rates were observed in males; after age 75, fractures were more common in females. Rates per 100,000 for different fractures were: radio-cubital 45.4, shine and fibula 41, ankle 28.1, humerus 25.3, and hip 23.5. Among males the figures were shine and fibula 66.2, radius and cubitus 64.9, face 37.5 and ankle 37.1. Among females, hip 28.2, radius and cubitus 26.3, ankle 19.3 and humerus 16.5. Hip fracture is clearly related to age, the incidence raising from below 60 per 100,000 under age 60 to 617 in females and 330 in males above that age. Other fractures that increase with age include radius and cubitus, shine and fibula, ankle, humerus and femur.