Lifestyle Walking Intervention for Patients With Heart Failure With Reduced Ejection Fraction: The WATCHFUL Trial

BACKGROUND

Physical activity is pivotal in managing heart failure with reduced ejection fraction, and walking integrated into daily life is an especially suitable form of physical activity. This study aimed to determine whether a 6-month lifestyle walking intervention combining self-monitoring and regular telephone counseling improves functional capacity assessed by the 6-minute walk test (6MWT) in patients with stable heart failure with reduced ejection fraction compared with usual care.

METHODS

The WATCHFUL trial (Pedometer-Based Walking Intervention in Patients With Chronic Heart Failure With Reduced Ejection Fraction) was a 6-month multicenter, parallel-group randomized controlled trial recruiting patients with heart failure with reduced ejection fraction from 6 cardiovascular centers in the Czech Republic. Eligible participants were ≥18 years of age, had left ventricular ejection fraction <40%, and had New York Heart Association class II or III symptoms on guidelines-recommended medication. Individuals exceeding 450 meters on the baseline 6MWT were excluded. Patients in the intervention group were equipped with a Garmin vívofit activity tracker and received monthly telephone counseling from research nurses who encouraged them to use behavior change techniques such as self-monitoring, goal-setting, and action planning to increase their daily step count. The patients in the control group continued usual care. The primary outcome was the between-group difference in the distance walked during the 6MWT at 6 months. Secondary outcomes included daily step count and minutes of moderate to vigorous physical activity as measured by the hip-worn Actigraph wGT3X-BT accelerometer, NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity C-reactive protein biomarkers, ejection fraction, anthropometric measures, depression score, self-efficacy, quality of life, and survival risk score. The primary analysis was conducted by intention to treat.

RESULTS

Of 218 screened patients, 202 were randomized (mean age, 65 years; 22.8% female; 90.6% New York Heart Association class II; median left ventricular ejection fraction, 32.5%; median 6MWT, 385 meters; average 5071 steps/day; average 10.9 minutes of moderate to vigorous physical activity per day). At 6 months, no between-group differences were detected in the 6MWT (mean 7.4 meters [95% CI, -8.0 to 22.7]; P=0.345, n=186). The intervention group increased their average daily step count by 1420 (95% CI, 749 to 2091) and daily minutes of moderate to vigorous physical activity by 8.2 (95% CI, 3.0 to 13.3) over the control group. No between-group differences were detected for any other secondary outcomes.

CONCLUSIONS

Whereas the lifestyle intervention in patients with heart failure with reduced ejection fraction improved daily steps by about 25%, it failed to demonstrate a corresponding improvement in functional capacity. Further research is needed to understand the lack of association between increased physical activity and functional outcomes.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03041610.

Statistical analysis plan for a randomized controlled trial examining pedometer-based walking intervention in patients with heart failure with reduced ejection fraction: the WATCHFUL trial

BACKGROUND

Physical activity is an effective management strategy for heart failure with reduced ejection fraction, but patients' compliance is challenging. Walking is a suitable form of physical activity due to its convenience and sustainability, and it can potentially improve functional capacity in heart failure patients.

OBJECTIVES

The WATCHFUL trial aims to determine whether a pedometer-based walking intervention combined with face-to-face sessions and regular telephone contact improves functional capacity in heart failure patients.

METHODS

The WATCHFUL trial is a 6-month multicenter, parallel-group, randomized, controlled, superiority trial with a 6-month follow-up. A total of 202 patients were recruited for the trial. The primary analysis will evaluate the change in distance walked during the 6-min walk test from baseline to 6 months based on the intention-to-treat population; the analysis will be performed using a linear mixed-effect model adjusted for baseline values. Missing data will be imputed using multiple imputations, and the impact of missing data will be assessed using a sensitivity analysis. Adverse events are monitored and recorded throughout the trial period.

DISCUSSION

The trial has been designed as a pragmatic trial with a scalable intervention that could be easily translated into routine clinical care. The trial has been affected by the COVID-19 pandemic, which slowed patients' recruitment and impacted their physical activity patterns.

CONCLUSIONS

The present publication provides details of the planned statistical analyses for the WATCHFUL trial to reduce the risks of reporting bias and erroneous data-driven results.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier: NCT03041610, registered: 3/2/2017).

Moderate-to-vigorous physical activity of HFrEF patients is strongly associated with age, but not with functional capacity (6MWT), ejection fraction, NYHA, NT-proBNP, sex or BMI

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Czech Health Research Council of the Ministry of Health of the Czech Republic

Introduction

Patients with heart failure with reduced ejection fraction (HFrEF) commonly have impaired functional capacity and exercise intolerance which negatively affect their daily living activities and quality of life. Patients’ level of moderate-to-vigorous physical activity (MVPA) remains low. A popular, easily incorporated into everyday life activity is walking, which at a pace of 5 km/h can be considered moderate intensity physical activity. We explored whether the level of MVPA in HFrEF patients is associated with certain demographic and clinical parameters.

Methods

We analysed baseline values of HFrEF patients recruited in a multicentre randomised controlled trial of a six-month walking intervention (WATCHFUL trial, ClinicalTrials.gov identifier: NCT03041610). Their physical activity was objectively measured over seven days using accelerometer ActiGraph wGT3X-BT worn on the waist. Weekly minutes of MVPA were calculated using Freedson (1998) algorithm. The association between minutes of MVPA and sex, age, body mass index (BMI), HF symptoms (NYHA class), left ventricular ejection fraction (LVEF), serum levels of NT-proBNP, and distance walked in a six-minute walk test (6MWT) was explored in a series of univariate and multivariate linear regression models.

Results

One hundred twenty-two patients were included in the analysis (31 females and 81 males, age 63.2±11.7 years, BMI 30.1±5.4, NYHA class II/III: 99/13, LVEF 30.5±7.0%, NT-proBNP 1169±1888 ng/L, 6MWT 365±61 m). They accumulated 33.8±40.3 min/week of MVPA. The weekly minutes of MVPA were negatively associated with patients' age: being one year older was associated with 1.8 min (SE 0.3) less MVPA (p &lt; 0.001). Neither sex, BMI, NYHA Class, distance walked in 6MWT, nor serum levels of NT-proBNP were associated with weekly minutes of MVPA.

Conclusion

Our results show that moderate-to-vigorous physical activity of HFrEF patients was strongly associated only with age. Surprisingly, commonly used prognostic markers of heart failure such as ejection fraction, NYHA, NT-proBNP, and functional capacity (6MWT) did not show significant. Neither did sex nor BMI. Exercise rehabilitation and increased physical activity improve functional capacity and should be regularly recommended, and even emphasised with age.

Global perspective of familial hypercholesterolaemia: a cross-sectional study from the EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

BACKGROUND

The European Atherosclerosis Society Familial Hypercholesterolaemia Studies Collaboration (FHSC) global registry provides a platform for the global surveillance of familial hypercholesterolaemia through harmonisation and pooling of multinational data. In this study, we aimed to characterise the adult population with heterozygous familial hypercholesterolaemia and described how it is detected and managed globally.

METHODS

Using FHSC global registry data, we did a cross-sectional assessment of adults (aged 18 years or older) with a clinical or genetic diagnosis of probable or definite heterozygous familial hypercholesterolaemia at the time they were entered into the registries. Data were assessed overall and by WHO regions, sex, and index versus non-index cases.

FINDINGS

Of the 61 612 individuals in the registry, 42 167 adults (21 999 [53·6%] women) from 56 countries were included in the study. Of these, 31 798 (75·4%) were diagnosed with the Dutch Lipid Clinic Network criteria, and 35 490 (84·2%) were from the WHO region of Europe. Median age of participants at entry in the registry was 46·2 years (IQR 34·3-58·0); median age at diagnosis of familial hypercholesterolaemia was 44·4 years (32·5-56·5), with 40·2% of participants younger than 40 years when diagnosed. Prevalence of cardiovascular risk factors increased progressively with age and varied by WHO region. Prevalence of coronary disease was 17·4% (2·1% for stroke and 5·2% for peripheral artery disease), increasing with concentrations of untreated LDL cholesterol, and was about two times lower in women than in men. Among patients receiving lipid-lowering medications, 16 803 (81·1%) were receiving statins and 3691 (21·2%) were on combination therapy, with greater use of more potent lipid-lowering medication in men than in women. Median LDL cholesterol was 5·43 mmol/L (IQR 4·32-6·72) among patients not taking lipid-lowering medications and 4·23 mmol/L (3·20-5·66) among those taking them. Among patients taking lipid-lowering medications, 2·7% had LDL cholesterol lower than 1·8 mmol/L; the use of combination therapy, particularly with three drugs and with proprotein convertase subtilisin-kexin type 9 inhibitors, was associated with a higher proportion and greater odds of having LDL cholesterol lower than 1·8 mmol/L. Compared with index cases, patients who were non-index cases were younger, with lower LDL cholesterol and lower prevalence of cardiovascular risk factors and cardiovascular diseases (all p<0·001).

INTERPRETATION

Familial hypercholesterolaemia is diagnosed late. Guideline-recommended LDL cholesterol concentrations are infrequently achieved with single-drug therapy. Cardiovascular risk factors and presence of coronary disease were lower among non-index cases, who were diagnosed earlier. Earlier detection and greater use of combination therapies are required to reduce the global burden of familial hypercholesterolaemia.

FUNDING

Pfizer, Amgen, Merck Sharp & Dohme, Sanofi-Aventis, Daiichi Sankyo, and Regeneron.

The detrimental effect of COVID-19 nationwide quarantine on accelerometer-assessed physical activity of heart failure patients

AIMS

A reduction of habitual physical activity due to prolonged COVID-19 quarantine can have serious consequences for patients with cardiovascular diseases, such as heart failure. This study aimed to explore the effect of COVID-19 nationwide quarantine on accelerometer-assessed physical activity of heart failure patients.

METHODS AND RESULTS

We analysed the daily number of steps in 26 heart failure patients during a 6-week period that included 3 weeks immediately preceding the onset of the quarantine and the first 3 weeks of the quarantine. The daily number of steps was assessed using a wrist-worn accelerometer worn by the patients as part of an ongoing randomized controlled trial. Multilevel modelling was used to explore the effect of the quarantine on the daily step count adjusted for weather conditions. As compared with the 3 weeks before the onset of the quarantine, the step count was significantly lower during each of the first 3 weeks of the quarantine (P < 0.05). When the daily step count was averaged across the 3 weeks before and during the quarantine, the decrease amounted to 1134 (SE 189) steps per day (P < 0.001), which translated to a 16.2% decrease.

CONCLUSIONS

The introduction of the nationwide quarantine due to COVID-19 had a detrimental effect on the level of habitual physical activity in heart failure patients, leading to an abrupt decrease of daily step count that lasted for at least the 3-week study period. Staying active and maintaining sufficient levels of physical activity during the COVID-19 pandemic are essential despite the unfavourable circumstances of quarantine.

Patient perception of anticoagulant treatment for stroke prevention (RE-SONANCE study)

Objective

We evaluated atrial fibrillation (AF) patients' perceptions of anticoagulation treatment with dabigatran or a vitamin K antagonist (VKA) for stroke prevention, according to accepted indications.

Methods

The RE-SONANCE observational, prospective, multicentre, international study used the validated Perception on Anticoagulant Treatment Questionnaire (PACT-Q) to assess patients with AF already taking a VKA who were switched to dabigatran (cohort A), and newly diagnosed patients initiated on either dabigatran or a VKA (cohort B). Visit 1 (V1) was at baseline, and visit 2 (V2) and visit 3 (V3) were at 30-45 and 150-210 days after baseline, respectively. Primary outcomes were treatment satisfaction and convenience in cohort A at V2 and V3 versus baseline, and in cohort B for dabigatran and a VKA at V2 and V3.

Results

The main analysis set comprised 4100 patients in cohort A and 5365 in cohort B (dabigatran: 3179; VKA: 2186). In cohort A, PACT-Q2 improved significantly (p<0.001 for all) for treatment convenience (mean change V1 vs V2=20.72; SD=21.50; V1 vs V3=24.54; SD=22.85) and treatment satisfaction (mean change V1 vs V2=17.60; SD=18.76; V1 vs V3=21.04; SD=20.24). In cohort B, mean PACT-Q2 scores at V2 and V3 were significantly higher (p<0.001 for all) for dabigatran versus a VKA for treatment convenience (V2=18.38; SE =0.51; V3=23.34; SE=0.51) and satisfaction (V2=15.88; SE=0.39; V3=19.01; SE=0.41).

Conclusions

Switching to dabigatran from long-term VKA therapy or newly initiated dabigatran is associated with improved patient treatment convenience and satisfaction compared with VKA therapy.

Risk factors detection in chronic thromboembolic pulmonary hypertension, a tool for risk quantification?

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by chronic thromboembolic obstruction in the pulmonary bed. The definitive pathogenesis remains incompletely explained, although multiple risk factors of CTEPH have been identified. The purpose of the study was to evaluate the risk profile of patients with CTEPH and the representativeness of risk factors, identify possible new CTEPH risk factors and specify the epidemiology of CTEPH in our country.

METHODS

In 81 patients with CTEPH, well known risk factors were analyzed, and a detailed analysis of selected hematological parameters was investigated at a specialized hematology laboratory.

RESULTS

CTEPH risk factors were identified as follows: pulmonary embolism (PE), deep vein thrombosis (DVT), thyreopathy, blood type other than "0", inflammatory bowel disease, malignancy, splenectomy, pacemaker. When compared to healthy controls, the following was observed: a significant decrease in platelet count, higher mean platelet volume, higher spontaneous platelet aggregation, increase in von Willebrand factor and fibrinogen. The median of risk factors representativeness was 3 (PE, DVT, blood type other than "0"). The prevalence of CTEPH in adult population in our country is estimated to be 1.8 per 100,000 inhabitants.

CONCLUSION

In the study we confirmed multiple established risk factors of CTEPH, set their representativeness, identified some platelet abnormalities which could be a potential new risk marker and specified the prevalence of CTEPH (Tab. 5, Ref. 35).

A Comprehensive In Vitro Comparison of Preparation Techniques for Fat Grafting

BACKGROUND

Lipomodeling is a technique that uses the patient's own fat for tissue regeneration and augmentation. The extent of regenerative effect is reported to be determined by the numbers of adipose-derived stem cells and the viability of cells in processed adipose tissue which, together with other factors, influence the degree of graft retention. This study addresses whether differences exist in properties of fat graft obtained by three commonly used techniques.

METHODS

Adipose tissue harvested from the hypogastric regions of 14 patients was processed by decantation, centrifugation, and membrane-based tissue filtration. The morphology of each preparation was assessed by electron microscopy and overall cell viability was assessed by live/dead assay. The number of adipose-derived stem cells was determined and their stem cell character was assessed by the presence of cell surface molecules (i.e., CD105, CD90, CD31, and CD45) and by their capacity to differentiate into adipogenic and osteogenic lineages.

RESULTS

First, morphologies of processed fat samples obtained by individual procedures differed, but no preparation caused obvious damage to cellular or acellular components. Second, although the highest numbers of adipose-derived stem cells were contained in the upper fraction of centrifuged lipoaspirates, the difference between preparations was marginal. Third, the maximal concentration of adipose fraction (removal of watery component) of lipoaspirate was achieved by membrane-based tissue filtration. Finally, no significant differences in overall viability were detected.

CONCLUSIONS

Properties of processed lipoaspirate were influenced by the preparation procedure. However, the differences were not dramatic; both centrifugation and membrane-based filtration are methods of choice whose selection depends on other criteria (e.g., practicality) for individual surgical settings.

DELAY PROCEDURE IN THE PERFORASOME ERA: A CASE IN A DIEAP FLAP

The deep inferior epigastric artery perforator (DIEAp) flap is becoming a widely used method of autologous breast reconstruction. Despite the huge use of the DIEAp flap in reconstructive field, an evidenced based approach in perforator selection has not yet been developed. Unfortunately there is no clear evidence about the relation between the number and dimension of the perforator vessel and the prediction of flap survival in a living model. An old technique like the vascular delay could be extremely useful as a lifeboat procedure when the vascularization of the flap after the dissection is inadequate.

A NOVEL MODEL TO EVALUATE THE LEARNING CURVE IN MICROSURGERY: SERIAL ANASTOMOSIS OF THE RAT FEMORAL ARTERY

The rat's femoral artery is definitely the most frequently used model in microsurgical training for its easy dissection. Our model, consisting in the creation of several anastomoses in a row, helps the novice surgeon to assess his microsurgical level and to improve his capacity. Indeed, this leads to an amplification of the trainee surgeon's mistakes, which add up to each other as the anastomoses are performed. We propose a simple method to evaluate the surgeon microsurgical skills during the training.

TWISTED DISTAL LATERAL ARM FLAP FOR IMMEDIATE RECONSTRUCTION OF THUMB AVULSION INJURY

BACKGROUND

Replantation is a complicated procedure in avulsion injuries in majority of the cases. When replantation of an avulsed thumb is not feasible, it is mandatory to find an appropriate reconstruction choice as soon as possible due to the importance of the thumb function in the dynamics of the handgrip.

MATERIALS AND METHODS

Three patients with skin avulsion injury underwent immediate reconstruction by twisted lateral arm flap in our department since 2004.

RESULTS

No infection, hematoma, partial or complete flap necrosis were observed after the procedure. All of the flaps healed without complications.

CONCLUSION

Although the gold standard in reconstruction of these trauma defects is the use of local skin flaps or distant inguinal flap, these reconstructive choices have multiple drawbacks such as the loss of sensibility and they are thicker. In thispaper we propose a modification of distally planned lateral arm flap design and a new technique of its spiral shaping for immediate thumb reconstruction.

The proximal first dorsal metacarpal artery free flap for reconstruction of complex digital defects

We describe our experience and outcome with the 'Proximal first dorsal metacarpal artery free flap'. Ten consecutive cases utilizing the proximal first dorsal metacarpal artery free flap for complex digital defects were studied. Surgical technique, patient demographics, and flap outcome data were collected. Patient satisfaction was analysed using a questionnaire. All defects healed successfully with no loss of free flaps. The short-pedicle proximal first dorsal metacarpal artery free flap enables primary closure of the donor site up to 2 cm of width (in nine of the ten donor sites). The flap is a reliable and versatile alternative in selected cases of complex digital injuries.

Radionavigated detection of sentinel nodes in breast carcinoma--first experiences of our department

INTRODUCTION

Biopsy and histological evaluation of sentinel lymphatic node limits the axillary node dissection only in cases of positive histological finding and decreases the occurrence of postoperative complications related to the axillary node dissection.

METHODS

We used radiotracer SentiScint, Medi-Radiopharma Ltd, Hungary and preoperatively administered blue dye--Blue Patenté V, Guebert, Aulnay-Sous-Bios, France. 11 (18%) patients were subdued to deep peritimorous application of radiotracer, 10 (16.4%) to sub/intradermal application over the lesions and n 40 (65.6%) patients the application was sub/intradermal and periareolar. The patients underwent an operation protocol of corresponding quadrantectomy, radionavigated blue-dye sentinel node biopsy and axillary dissection.

RESULTS AND CONCLUSIONS

From May 2006 to June 2008, we examined 61 patients with breast carcinoma. They underwent radionavigated and blue-dye sentinel node biopsy. We detected 57 (93.4%) sentinel nodes with preoperative scintigraphy, of which only 51 (83.6%) were detected peroperatively and underwent histological evaluation. In six (9.8%) cases, the "frozen cut" histology of the primary lesion had shown a benign lesion; hence no sentinel node biopsy or axillary disection was performed. 12 (19.7%) of 51 histologically evaluated sentinel nodes had metastatic invasion. We retrospectively compared the histological fund in sentinel and axillary nodes in patients with metastatic sentinel nodes. In 6 (16.6%) cases, the sentinel node was positive of metastatic invasion but axillary nodes were histologically negative, in 6 (16.6%) cases the sentinel node and axillary nodes were positive for metastatic invasion. We observed falsely negative findings in 3 (8.3%) patients with negative histological fund in the sentinel node, but positive axillary nodes (Tab. 3, Fig. 2, Ref. 11). Full Text (Free, PDF) www.bmj.sk.

Evaluation of early dynamic splinting versus static splinting for patients with transposition of the extensor carpi radialis longus to the extensor pollicis longus

We present a group of 20 patients who underwent transposition of the extensor carpi radialis longus to the extensor pollicis longus between April 2003 and September 2007. The group was divided into ten patients with an early dynamic splint and ten patients with a static plaster cast following the standard rehabilitation protocols. We compared these two rehabilitation protocols. The post-rehabilitation total range of motion was 87.5 degrees in the dynamic group and 58.75 degrees in the patients treated by the static protocol. The total time of rehabilitation was 10.2 weeks in the dynamic and 14.2 weeks in the static group. The overall mean follow-up was 12.2 weeks. We conclude that early dynamic splinting brings shorter recovery time, shorter time off work and significantly better movement of the thumb.

New laboratory markers in diagnosis of alzheimer dementia

OBJECTIVES

The aim of our work was to assess the role of tau protein, beta amyloid and cystatin C in diagnosis of Alzheimer dementia (AD) and other neurodegenerative diseases (NDs).

METHODS

The levels of tau protein, beta amyloid and cystatin C were assessed in a set of 79 patients with ND (38 men and 41 women; aged 22-90 years; mean, 61.6 +/- 15.6 years) and in a control group of 79 subjects with a healthy central nervous system (38 men and 41 women; aged 20-91 years; mean, 61.5 +/- 15.1 years).

RESULTS

When compared with the subjects in the control group, a statistically significant decrease in tau protein levels was found in patients with ND, an increase in tau protein levels in patients with AD and an increase in cystatin C cerebrospinal fluid/serum index in the ND + AD group.

DISCUSSION

Our work only confirmed the previously reported results in part. Although tau protein seems to be a quite reliable marker of AD, the role of beta amyloid in AD diagnosis remains at the least questionable. In the case of cystatin C, our results would seem to confirm the views of certain authors that cystatin C will probably not become a new 'revolutionary' marker contributing to differential diagnostics.

The assessment of beta amyloid, tau protein and cystatin C in the cerebrospinal fluid: laboratory markers of neurodegenerative diseases

To assess the role of tau protein, beta-amyloid(1-42) and cystatin C in the diagnostics of Alzheimer dementia (AD) and other neurodegenerative diseases (ND) by comparing to the control groups (CG). The levels of tau protein, beta-amyloid(1-42) and cystatin C were assessed in the set of 69 patients (AD + ND, 33 males, 36 females, aged 22-90, mean 60.5 + 16.1 years), and in a control group of 69 subjects without the affection of the central nervous system (CGAD + CGND, 33 males, 36 females, aged 20-91, mean 60.5 + 16.0 years). Statistically significant increased tau protein levels (P = 0.0001) and index tau/beta-amyloid(1-42) levels (P = 0.0002) were shown in the group of AD patients, compared to the group of ND patients. One-way ANOVA analysis with Bonferonni post hoc test did not show any significant differences of the cystatin C values between any of the compared groups. ROC analysis showed at least one tie between the positive actual state group (AD) and the negative actual state group (ND) by CSF cystatin C and at least one tie between the positive actual state group and the negative actual state group by CSF tau protein. Our study confirmed previously reported results only in part. While tau protein seems to be quite a reliable marker of AD, the role of beta-amyloid(1-42) and cystatin C in AD diagnosis remains at least questionable.

Bilateral breast reconstruction with DIEP flaps: 4 years’ experience

Bilateral prophylactic mastectomy without reconstruction is not accepted by the majority of patients. Successful reconstruction is therefore a mandatory condition for prophylactic mastectomy. Of the many options for autologous breast reconstruction, the deep inferior epigastric perforator (DIEP) flap best meets requirements for bilateral reconstruction in selected patients. The goal of this study is to verify the feasibility of the procedure in our conditions and to find out how it is accepted by patients. We present 55 consecutive patients who were scheduled for bilateral DIEP flap reconstruction during a 4-year period. We reviewed medical charts, performed clinical assessments and processed anonymous questionnaires. There were 77 immediate and 33 delayed breast reconstructions. There was 100% flap survival and no microanastomoses revisions. In 11 patients (10%) the surgeon preferred to convert the DIEP into a mini transverse rectus abdominis muscle (miniTRAM) flap in order to provide adequate blood supply.

COMPLICATIONS

revision for haematoma under the flap in four patients (7.2%), excessive blood loss in four patients (7.2%) and partial mastectomy skin flap necrosis in 10 immediate breast reconstructions (12.9%). Patients' evaluation of the aesthetic result was good or excellent in 96.2% of cases. In 33.9% of patients the postoperative quality of life was considered unchanged and 50.9% of them it even improved. The DIEP flap is recommended for bilateral breast reconstruction. Occasional conversion into a miniTRAM flap can increase the total flap survival rate. Bilateral prophylactic mastectomy and DIEP flap reconstruction are very well accepted by patients.

The preservation of a spare hemi-abdominal flap in unilateral breast reconstruction with abdominal free flap in high risk patients

BACKGROUND

Unilateral breast reconstruction with a free abdominal TRAM or DIEP flap restores the shape of the amputated breast with acceptable donor site morbidity. In patients with small breasts and ample lower abdominal tissue this can be achieved by using only a hemi-abdominal flap. In these cases, the contra-lateral flap is usually discarded, but it could potentially be left in situ as a "spare" hemi-abdominal flap, especially in patients at high risk for contra-lateral breast cancer or flap failure. We report our early experience with this preservation technique.

MATERIAL AND METHODS

The authors report two cases of unilateral breast reconstruction with hemi-abdominal DIEP free flaps in women at high risk for contra-lateral breast cancer and/or flap failure, who opted not to have prophylactic contra-lateral mastectomies. They consented to having the unused "spare" hemi-abdominal deepithelialized flap left in situ in case the need for a secondary flap arose.

RESULTS

The "spare" hemi-abdominal flap was used for immediate reconstruction as an SIEA free flap when the first patient's original flap necrosed secondary to microcirculation problems. The second patient's spare flap was left in situ by burying it after de-epithelialization.

CONCLUSIONS

We believe that patients undergoing unilateral breast reconstruction who are at high risk for contra-lateral breast cancer and/or free flap failure, and who choose not to undergo an immediate contra-lateral prophylactic mastectomy, should have the "spare" hemi-abdominal flap buried. This tissue could be used as a potential bailout flap in cases of original flap failure or for contralateral breast reconstruction at a later date.

Primary vein grafting in treatment of ring avulsion injuries: a 5-year prospective study

Out of 262 hands with total finger amputations treated by replantation of finger/fingers from January 2001 until January 2006, there were only 6 cases of type III ring avulsion injuries, all of which were replanted. Radical resection of the damaged part of the artery with primary vein grafting was used in each case; only 1 artery and 2 veins were anastomosed for each finger. The survival rate was 100%. Mean total active motion was 195 degrees (ranging from 175 degrees to 220 degrees ). Mean 2-point discrimination was 8.6 mm static (ranging from 4 to 11 mm) and 6.2 mm moving (ranging from 3 to 9 mm), and mean grip strength was 37.4 kg. We believe that liberal resection of the "zone of contusion" of vessels and primary vein grafting for arterial repair can improve the overall survival rate of replantation in type III ring avulsion injuries, and replantation can be attempted in majority of the cases; good hand function can be expected.

New technique of total phalloplasty with reinnervated latissimus dorsi myocutaneous free flap in female-to-male transsexuals

From December 2001 to September 2005, the technique of total penile reconstruction with a reinnervated free latissimus dorsi myocutaneous flap was used in 22 patients (24-38 years old) with gender dysphoria. These patients were followed up for at least 11 months (range, 11-44 months). All flaps survived. Complications include hematoma (7 cases), vascular thrombosis (2 cases), partial necrosis (1 case), excessive swelling of the neophallus (3 cases), and skin graft loss at the donor site (1 case). Of the 19 patients included in the final evaluation, the transplanted muscle was able to obtain contraction in 18 (95%) cases and 8 patients (42%) had sexual intercourse by contracting the muscle to stiffen and move the neopenis. The described technique of neophalloplasty proved to be a reliable technique and the muscle movement in the neophallus can be expected in almost all cases. The muscle contraction in the neophallus leads to "paradox" erection-stiffening, widening, and shortening of the neopenis, which allows for sexual intercourse in some patients. Subsequent reconstruction of the urethra is possible.

Rare incidence of pulmonary gangrene--algorithm of the treatment

The pulmonary gangrene is rare and serious disease. Our experience is based on the treatment of the 2 patients with pulmonary gangrene during the last twenty years. The first and lifesaving step in the treatment of sepsis is the early removal of the necrotic tissue. Next surgery succeeds usually after one week after initial treatment. Surgical treatment continues step by step, we do not advise providing of a major anatomical resection in the initial stage of the disease. This policy is effective in the treatment of this serious disease.

The Bilobed Arterialized Venous Free Flap for Simultaneous Coverage of 2 Separate Defects of a Digit

We report a case of a 17-year-old patient who sustained multiple finger contusions on the left hand. After thorough debridement, the volar and dorsal defects of the middle finger were covered simultaneously with bilobed arterialized venous free flap from the left forearm. The flap was composed of 2 paddles, which were connected by a subcutaneous bridge containing a subcutaneous venous network. The subdermal plexus in the bridge was interrupted with no impairment of blood supply to the second cutaneous paddle. The flap survived completely with only temporary mild venous congestion. Excellent functional and cosmetic result was reached. We consider bilobed arterialized venous free flap as a useful option for coverage of concomitant volar and dorsal digital defects.

Regional scale evidence for improvements in surface water chemistry 1990-2001

The main aim of the international UNECE monitoring program ICP Waters under the Convention of Long-range Transboundary Air Pollution (CLRTAP) is to assess, on a regional basis, the degree and geographical extent of the impact of atmospheric pollution, in particular acidification, on surface waters. Regional trends are calculated for 12 geographical regions in Europe and North America, comprising 189 surface waters sites. From 1990-2001 sulphate concentrations decreased in all but one of the investigated regions. Nitrate increased in only one region, and decreased in three North American regions. Improvements in alkalinity and pH are widely observed. Results from the ICP Waters programme clearly show widespread improvement in surface water acid-base chemistry, in response to emissions controls programs and decreasing acidic deposition. Limited site-specific biological data suggest that continued improvement in the chemical status of acid-sensitive lakes and streams will lead to biological recovery in the future.

Salivary non-immunoglobulin agglutinin inhibits human leukocyte elastase digestion of acidic proline-rich salivary proteins

Saliva contains acidic proline-rich salivary proteins that are involved in the formation of the salivary pellicle coating supragingival tooth surfaces. However, human leukocyte elastase, arriving in gingival exudates from inflamed periodontal tissues, degrades the acidic proline-rich salivary proteins, preventing binding to hydroxylapatite surfaces. Here it is reported that high-molecular-weight non-immunoglobulin salivary agglutinin inhibited the proteolytic action of human leukocyte elastase on purified acidic proline-rich salivary proteins. Inhibition was eliminated with monoclonal antibody to a protein determinant on the salivary agglutinin. The addition of antibody against salivary agglutinin blocked the inhibitory effect of parotid saliva on exogenously applied human leukocyte elastase, allowing for the elastase-mediated digestion of the salivary acidic proline-rich salivary proteins. Salivary agglutinin, therefore, is a physiologically important inhibitor of human leukocyte elastase and is able to inhibit elastase-mediated digestion of salivary acidic proline-rich proteins.

Effects of removing the negatively charged N-terminal region of the salivary acidic proline-rich proteins by human leucocyte elastase

Human leucocyte elastase from inflammatory gingival crevicular exudates (gingival crevicular fluid) contacts saliva and saliva-coated tooth surfaces coronal to the gingival margin. Major components of saliva are the salivary acidic proline-rich proteins (PRPs). These acidic PRPs, via the numerous negatively charged amino acid residues located predominantly within their amino-terminal region, bind to the hydroxyapatite mineral of the tooth surface and become part of the salivary pellicle. Thus the potential for human leucocyte elastase-mediated removal of the negatively charged amino-terminal region of acidic PRP variants (PRP-1, PRP-2, PRP-3, PRP-4, PIF-s and PIF-f) was examined. It was determined that each of the acidic PRP variants was susceptible to fragmentation by human leucocyte elastase, in which the 16 amino-terminal segment was removed, leaving the respective residual fragment named as the transitional product (tr). The transitional products were termed PRP-1tr, PRP-2tr (PIF-str), PRP-3tr and PRP-4tr (PIF-ftr). Each of the residual transitional products of acidic PRP had an amino-terminal beginning with serine residue no. 17, determined by amino acid sequencing. When samples of human leucocyte elastase-treated acidic PRPs were placed on native polyacrylamide gels and electrophoresed, the respective transitional products moved more slowly than the parental acidic PRP molecules, reflecting the loss of a portion of the negatively charged section. In comparison to the acidic PRPs, the acidic PRP transitional products had markedly reduced binding to hydroxyapatite. The transitional products were resistant to further enzymatic digestion as a function of increased incubation time and appeared to exert an antihuman leucocyte elastase effect. However, when increased concentrations of human leucocyte elastase were incubated with the acidic PRP, a more extensive digestion occurred, leaving a residual peptide with an amino-terminal beginning with alanine residue no. 44. Interestingly, intact acidic PRPs if prebound to hydroxyapatite particles, resisted digestion by human leucocyte elastase. In summary, human leucocyte elastase was capable of digesting fluid-phase (unbound) acidic PRP in a manner that eliminated part of their negatively charged region, which subsequently reduced their binding to hydroxyapatite. High concentrations of human leucocyte elastase, arriving from inflammatory gingival crevicular exudates, may interrupt the normal binding of fluid-phase acidic PRPs to hydroxyapatite.

Modulation of the apoptotic response of human myeloid leukemia cells to a diphtheria toxin granulocyte-macrophage colony-stimulating factor fusion protein

It has previously been shown that human granulocyte-macrophage colony-stimulating factor (GM-CSF) can be fused to a truncated diphtheria toxin (DT) to produce a recombinant fusion toxin that kills GM-CSF receptor-bearing cells. We now report that DT388-GM-CSF induces apoptosis and inhibition of colony formation in semisolid medium in receptor positive cells, and that the induction of apoptosis correlates with GM-CSF-receptor occupancy at low ligand concentrations. Also, the induction of apoptosis correlates with the inhibition of protein synthesis and is inversely related to the amount of intracellular antiapoptotic proteins (Bcl2 and Bc1XL). Nine myeloid leukemia cells lines and four nonmyeloid leukemia cell lines were incubated with 0.7 nmol/L of 125I-GM-CSF in the presence or absence of excess cold GM-CSF and bound label measured. High affinity receptor numbers varied from 0 to 291 molecules per cell. Cells were incubated with varying concentrations of recombinant fusion toxin for 48 hours and incorporation of 3H-leucine (protein synthesis), segmentation of nuclei after DAPI staining (apoptosis), and colony formation in 0.2% agarose (clonogenicity) were measured. DT388-GM-CSF at 4 x 10(-9) mol/L inhibited colony formation 1.5 to 3.0 logs for receptor positive cell lines. Protein synthesis and apoptosis IC50s varied among cell lines from greater than 4 x 10(-9) mol/L to 3 x 10(-13) mol/L. GM-CSF-receptor occupancy at 0.7 nmol/L GM-CSF-ligand concentration correlated with the protein synthesis IC50. Similarly, the protein synthesis inhibition and apoptosis induction correlated well, except in cells overexpressing Bcl2 and BclXL, in which 25- to 150-fold inhibition of apoptosis was observed. We conclude that DT388-GM-CSF can kill acute myeloid leukemia blasts but that apoptotic sensitivities will depend on the presence of at least 100 high affinity GM-CSF receptors/cell and the absence of overexpressed antiapoptotic proteins.

Synthesis of green fluorescent protein-ricin and monitoring of its intracellular trafficking

We performed genetic engineering to fuse enhanced green fluorescent protein (EGFP) to the N terminus of RTA, expressed the fusion protein in Escherichia coli, purified and reassociated EGFP-RTA with plant RTB, and purified EGFP-ricin by size exclusion HPLC. The fusion heterodimer was able to bind galactosides, intoxicate cells, and show strong fluorescence. Mammalian cells incubated with EGFP-ricin showed strong cell surface fluorescence at 4 degrees C and, on incubation at 37 degrees C, distributed initially to endosomes and then to Golgi vesicles. Variable sensitivity of mammalian cells to ricin and ricin fusion proteins may be due in part to different patterns of intracellular routing. Cells were incubated with ricin or EGFP-ricin, and inhibition of protein synthesis was measured. Human hepatocellular carcinoma Hep3B cells were 10-fold more sensitive to ricin and 85-fold more sensitive to EGFP-ricin than human epidermoid carcinoma KB cells. Epifluorescence microscopy of cells incubated with EGFP-ricin showed greater localization of the fluorescence signal in the Golgi compartments in Hep3B cells than in KB cells. These data support a model requiring a Golgi-dependent step in cell intoxication by ricin. The work further identifies the usefulness of green fluorescent protein fusions in the study of retrograde transport of internalized peptides.

Major DNA fragmentation is a late event in apoptosis

Apoptosis, the terminal morphological and biochemical events of programmed cell death, is characterized by specific changes in cell surface and nuclear morphology. In addition, DNA fragmentation in an internucleosomal pattern is detectable in mass cultures of apoptotic cells. However, DNA fragmentation and nuclear morphological changes may not necessarily be associated events. In this study, we examined OVCAR-3 and KB human carcinoma cells using time-lapse video phase-contrast microscopy to characterize the surface and nuclear morphological features of apoptosis in response to treatment with either taxol or ricin. The surface morphological features of apoptosis were the same in both cell types and with both drugs. Using an in situ nick-translation histochemical assay, these single cells were also examined for DNA strand breaks during apoptosis. Surface morphological changes demonstrated discrete stages of cell rounding, surface blebbing, followed by cessation of movement and the extension of thin surface microspikes, followed much later by surface blistering and cell lysis. Nuclear features examined by DAPI cytochemistry demonstrated apoptotic nuclear condensation very early in this sequence, usually at the time of initial surface blebbing. The nick-translation assay, however, demonstrated DNA strand breaks at a much later time, only after the formation of separated apoptotic bodies or after final cell lysis. This study points out the differences between surface and nuclear morphological changes in apoptosis, and the large temporal separation between nuclear morphological changes and major DNA fragmentation detectable by this in situ technique. This result suggests caution in using in situ nick-translation as a direct correlate of internucleosomal DNA fragmentation in apoptosis.

Lectin-deficient ricin toxin intoxicates cells bearing the D-mannose receptor

Ricin toxin with genetic or chemical modification of lectin sites has been previously reported to show markedly reduced cytotoxicity to cells following uptake by several receptors including the mannose receptor. Investigators have hypothesized that an intracellular galactoside-binding function was required for optimal intracellular targeting of ricin for these receptors. We have prepared insect-derived mutant ricin toxin B chain (RTB) with modifications of three lectin side domains (1 alpha, 1 beta, and 2 gamma) yielding a 1000-fold reduced galactoside avidity. After reassociation with plant RTA, the recombinant heterodimer and plant ricin were tested for cytotoxicity on mammalian cells expressing (mouse peritoneal macrophages, J774E cells, and MMR61 cells) or not expressing (KB cells) the D-mannose receptor. Receptor expression was confirmed by immunofluorescence microscopy. Lactose was included in the media to block cell-surface galactoside binding, and mannan was added as a control in each experiment to confirm mannose receptor-specific targeting. Plant ricin A chain (RTA) and E. coli-derived RTA were also tested for cytotoxicity on J774E and KB cells. Both wild-type and lectin-deficient ricin displayed mannose-receptor mediated cell cytotoxicity. This is the first report of a genetically modified ricin showing that RTB intracellular galactose binding activity is not required for ricin cytotoxicity. Sensitivity of mannose-receptor bearing cells, but not control cells, to mannosylated RTA, but not unglycosylated RTA, confirmed these observations. These results imply fusion toxins employing ricin can be prepared with maximal reductions in normal tissue binding.

The down-regulated in adenoma (DRA) gene encodes an intestine-specific membrane glycoprotein

The protein product of the DRA gene, a gene whose expression is down-regulated in colon adenomas and adenocarcinomas, is a membrane glycoprotein and a member of a family of sulfate transporters. It is expressed in the intestinal tract (duodenum, ileum, cecum, distal colon), but not in the esophagus or stomach. DRA mRNA expression is restricted to the mucosal epithelium, and DRA protein expression is further limited to the columnar epithelial cells, particularly to the brush border. Consistent with its expression in the differentiated columnar epithelium of the adult human colon, DRA is first expressed in the midgut of developing mouse embryos at day 16.5, corresponding with the time of differentiation of the epithelium of the small intestine. A model for the structure of the DRA protein is proposed and its possible role in colon tumorigenesis is discussed.

Characterization of single site ricin toxin B chain mutants

DNA encoding ricin B chain was modified by site-directed mutagenesis, and eight separate mutant RTB cDNAs including four novel mutants were ligated into the baculovirus transfer vector, pAcGP67A. Cotransfection of S. frugiperda Sf9 cells with BaculoGold DNA was followed by limiting dilution isolation of recombinant baculoviruses. Infection of Sf9 cells at a multiplicity of infection of 5 in the presence of 25 mM lactose produced 0.05-1 mg/L of soluble, glycosylated 34 kDa proteins immunoreactive with monoclonal and polyclonal antibodies to ricin B chain. Mutant ricin B chains were partially purified by monoclonal antibody immunoaffinity chromatography to 10-50% purity in near milligram quantities. The mutant ricin B chains had decreased lectin binding relative to plant ricin B chain as measured by binding to immobilized lactose and asialofetuin and cell binding immunofluorescence. The mutant ricin B chains reassociated with plant RTA similarly to plant RTB, and the recombinant heterodimers had slightly reduced cell cytotoxicity relative to ricin.

IL2-ricin fusion toxin is selectively cytotoxic in vitro to IL2 receptor-bearing tumor cells

Fusion toxins consist of peptide ligands linked through amide bonds to polypeptide toxins. The ligand directs the molecule to the surface of target cells and the toxin enters the cytosol and induces cell death. Ricin toxin is an excellent candidate for use in fusion toxins because of its extreme potency, the extensive knowledge of its atomic structure, and the years of experience with RTA chemical conjugates in clinical trials. We synthesized a baculovirus transfer vector with the polyhedrin promoter followed sequentially from the 5' end with DNA encoding the gp67A leader sequence, the tripeptide ADP, IL2, another ADP tripeptide, and RTB. Recombinant baculovirus was generated in Sf9 insect cells and used to infect Sf9 cells. Recombinant IL2-RTB protein was recovered at high yields from day 5 insect cell supernatants, partially purified by affinity chromatography, and characterized. The recombinant product was soluble and immunoreactive with antibodies to RTB and IL2, bound asialofetuin and lactose, and reassociated with RTA. In the presence of lactose to block galactose-binding sites on RTB, the IL2-RTB-RTA heterodimer was selectively cytotoxic to IL2 receptor, bearing cells. Specific cytotoxicity could be blocked with IL2. Thus, we report a novel targeted plant toxin fusion protein with full biological activity.

Multiple modes of ligand recognition: crystal structures of cyclin-dependent protein kinase 2 in complex with ATP and two inhibitors, olomoucine and isopentenyladenine

Cyclin-dependent kinases (CDKs) are conserved regulators of the eukaryotic cell cycle with different isoforms controlling specific phases of the cell cycle. Mitogenic or growth inhibitory signals are mediated, respectively, by activation or inhibition of CDKs which phosphorylate proteins associated with the cell cycle. The central role of CDKs in cell cycle regulation makes them a potential new target for inhibitory molecules with anti-proliferative and/or anti-neoplastic effects. We describe the crystal structures of the complexes of CDK2 with a weakly specific CDK inhibitor, N6-(delta 2-isopentenyl)adenine, and a strongly specific inhibitor, olomoucine. Both inhibitors are adenine derivatives and bind in the adenine binding pocket of CDK2, but in an unexpected and different orientation from the adenine of the authentic ligand ATP. The N6-benzyl substituent in olomoucine binds outside the conserved binding pocket and is most likely responsible for its specificity. The structural information from the CDK2-olomoucine complex will be useful in directing the search for the next generation inhibitors with improved properties.

Expression of ricin B chain in Spodoptera frugiperda

DNA encoding ricin B chain was derived from preproricin genomic DNA and ligated into the baculovirus transfer vector, pAcGP67A. Co-transfection of Spodoptera frugiperda Sf9 cells with BaculoGold DNA was followed by limiting dilution purification of recombinant baculovirus. Infection of SF9 cells at a multiplicity of infection of 1 in the presence of 25 mM lactose produced 3 mg/l of soluble, glycosylated, 34 kDa protein immunoreactive with monoclonal and polyclonal antibodies to ricin B chain. The recombinant ricin B chain had similar lectin-binding activity to plant ricin B chain. The recombinant protein reassociated with ricin toxin A chain similarly to ricin toxin B chain and the recombinant heterodimers had similar cell cytotoxicity to ricin.

Expression of oligohistidine-tagged ricin B chain in Spodoptera frugiperda

DNA encoding ADPGH6G was fused to the 5'-end of RTB DNA and subcloned as a BamHI-EcoRI DNA cassette into the baculovirus transfer vector, pAcGP67A. Spodoptera frugiperda Sf9 cells were cotransfected with pAcGP67A-ADPGH6G-RTB DNA and BaculoGold AcNPV DNA, and recombinant baculovirus was isolated by two cycles of limiting dilution assay followed by dot blot analysis with 32P-dCTP random primer labeled RTB DNA. Recombinant virus was purified and amplified to obtain stocks at titers of 10(7) infectious particles/mL. Sf9 cells grown in serum-free medium were then infected at an moi of 3 in the presence of 25 mM alpha-lactose. After 5 days, supernatants and cell pellets were harvested and assayed by an asialofetuin ELISA for recombinant RTB protein. Fusion RTB protein was produced in the supernatant at 5 mg/L and in the cell pellet at 1 mg/L. Recombinant protein was purified to > 80% homogeneity using either a monoclonal antibody affinity matrix with alkaline elution or a Ni(2+)-NTA matrix with imidazole elution. The purified protein bound asialofetuin similarly to plant RTB. N-terminal sequencing confirmed the oligohistidine tag. SDS-PAGE confirmed the 1,000 Da increase in mass relative to "wild-type" recombinant RTB produced in Sf9 cells. Immunoblots confirmed reactivity with polyclonal and monoclonal antibodies to plant RTB. The fusion protein reassociated with plant RTA similarly to plant RTB.(ABSTRACT TRUNCATED AT 250 WORDS)

High molecular weight non-immunoglobulin salivary agglutinins (NIA) bind C1Q globular heads and have the potential to activate the first complement component

Non-Immunoglobulin Salivary Agglutinins (NIA) which directly bind to microbes [including HIV] were studied for their potential to activate the first complement component (C1). It was determined that NIA had the same specific activity as heat aggregated IgG in binding to C1q and in activating C1. In order to determine the region of C1q which bound to NIA, C1q globular heads and C1q stems (collagen-like regions) were prepared and separated via a Western blot procedure. NIA bound principally to the globular heads of C1q and weakly to the collagen-like stem region. NIA were also studied for their potential to activate native C1 in normal human serum. Heat-aggregated IgG and cardiolipin served as positive controls. It was observed that incubation of isolated NIA with fresh normal human serum resulted in the formation of sodium dodecyl sulfate (SDS)-irreversible complexes of activated C1r-C1 inhibitor and activated C1s-C1 inhibitor and in activated C1s mediated C4 conversion. This indicated that isolated NIA had the potential to directly and effectively mediate classical complement pathway activation. Preincubation of NIA with C1q, blocked NIA mediated C1r and C1s activation and C4 conversion. The concn of NIA required to activate C1r and C1s was similar to that of heat-aggregated human IgG. In kinetic ELISA, NIA or aggregated IgG (positive controls) were first immobilized on microtiter plates, blocked with gelatin then incubated with fresh human serum as a source of complement. Depositions of C4b, C3b and iC3b substantiated that the complement system was effectively activated by immobilized NIA. The optimal relative NaCl concn for C4b deposition was 0.11 M. While pre-incubation of NIA with C1q blocked the subsequent C1 fixing potential of NIA, pre-incubation of NIA with rgp160 [HIV-1] or fibronectin did not interfere with the potential of NIA to fix C1.

Complement activation as a possible in vitro indication of the inflammatory potential of endodontic materials

Samples of four brands of gutta-percha and the nine ingredients that make up one brand were studied in vitro to observe their interaction with the serum complement system, thus allowing for assessment of their possible inflammatory potential. Crossed immunoelectrophoresis of the third complement component was used as an indicator of complement activation. The four different brands of gutta-percha showed comparable complement activation as determined by C3 conversion. When the ingredients of one brand of gutta-percha were examined for complement-activating properties, major activities were associated with gutta-percha compound, agerite stalite-antioxidant, and titanium oxide food grade. The significance of the possible inflammatory potential of gutta-percha and its ingredients, as it relates to endodontic therapy, is discussed.

Azapyrimidine nucleosides: metabolism and inhibitory mechanisms

Triazine nucleosides represent highly active compounds affecting different cellular processes. While 6-azauridine displays a rather selective inhibitory effect, biological action of 5-azacytidine reflects the polyvalent inhibitory mechanism of the drug (interaction with pyrimidine synthesis de novo, incorporation into RNA and DNA, depressed maturation of ribosomal RNA, inhibition of RNA and DNA methylation, etc.) and the analog displays pronounced cytostatic and immunosuppressive activity. 5-Aza-2'-deoxycytidine action is directed against DNA synthesis similar to that of 5-azacytosine arabinoside. N4-Substituted derivatives of 5-azacytidine affect gastric secretion and together with 5-azacytosine and 5-azacytidine represent a new type of drugs with antiulcer activity. 6-Amino-5-azacytosine nucleosides interfere with the metabolism of purines rather than pyrimidines as evidenced by the character of their inhibitory mechanism and measurement of conformation. 6-Azauridine (as 2',3',5'-triacetate) and 5-azacytidine were used with certain success in human chemotherapy, the first one as a drug affecting recalcitrant psoriasis, the second one for the treatment of different forms of leukemia. The inhibitory mechanisms of individual azapyrimidine nucleosides are discussed in relation to their known biological effects.

Effects of substituted dithiocarbamates on the testicular toxicity of cadmium

Five substituted dithiocarbamates were evaluated for effectiveness in protecting mouse testes following administration of an LD100 dose of CdCl2 X 2.5 H2O (Cd). Toxicologic responses were assessed by light microscopic, electron microscopic, and computerized image analysis techniques. Diethyldithiocarbamate (DDTC) was the most effective antagonist. N-ethyl-N-hydroxyethyldithiocarbamate (EHDC), N-methyl-N-hydroxyethyldithiocarbamate (MHDC), and dimethyldithiocarbamate (DMDC) were moderately to minimally effective, while di-(hydroxyethyl)dithiocarbamate (DHDC) afforded no protection. Degenerative changes increased progressively in severity as the time interval between administration of Cd and DDTC was increased, but remained minimal when DDTC was given as late as two hours after Cd.