'Quer N0 AVC' for Monitoring Stroke Patients' Healthcare Using a Mobile App

Stroke is one of the leading causes of death and impairments worldwide. After hospital discharge, it is necessary to monitor these patients during their recovery. This research addresses the implementation of a mobile app, entitled 'Quer N0 AVC', to improve the quality of stroke patient care in Joinville, Brazil. The study method was divided into two parts. The adaptation phase included all the necessary information in the app for monitoring stroke patients. The implementation phase aimed to prepare a routine for the Quer mobile app installation. One of the questionnaires collected data from 42 patients and identified that before hospital admission 29% of them did not have medical appointments, 36% had one or two appointments, 11% had three appointments, and 24% had four or more appointments. This research portrayed adaptation feasibility and the implementation of a cell phone app for following up on stroke patients.

Stroke profile and care during the COVID-19 pandemic: What changed and what did not? A prospective cohort from Joinville, Brazil

Introduction

The COVID-19 pandemic has wrought negative consequences concerning quality of care for stroke patients since its onset. Prospective population-based data about stroke care in the pandemic are limited. This study aims to investigate the impact of COVID-19 pandemic on stroke profile and care in Joinville, Brazil.

Methods

A prospective population-based cohort enrolled the first-ever cerebrovascular events in Joinville, Brazil, and a comparative analyzes was conducted between the first 12 months following COVID-19 restrictions (starting March 2020) and the 12 months just before. Patients with transient ischemic attack (TIA) or stroke had their profiles, incidences, subtypes, severity, access to reperfusion therapy, in-hospital stay, complementary investigation, and mortality compared.

Results

The profiles of TIA/stroke patients in both periods were similar, with no differences in gender, age, severity, or comorbidities. There was a reduction in incidence of TIA (32.8%; p = 0.003). In both periods, intravenous thrombolysis (IV) and mechanical thrombectomy (MT) rates and intervals from door to IV/MT were similar. Patients with cardioembolic stroke and atrial fibrillation had their in-hospital stay abbreviated. The etiologic investigation was similar before and during the pandemic, but there were increases in cranial tomographies (p = 0.02), transthoracic echocardiograms (p = 0.001), chest X-rays (p < 0.001) and transcranial Doppler ultrasounds (p < 0.001). The number of cranial magnetic resonance imaging decreased in the pandemic. In-hospital mortality did not change.

Discussion

The COVID-19 pandemic is associated with a reduction in TIA, without any influence on stroke profile, the quality of stroke care, in-hospital investigation or mortality. Our findings show an effective response by the local stroke care system and offer convincing evidence that interdisciplinary efforts are the ideal approach to avoiding the COVID-19 pandemic's negative effects, even with scarce resources.

Incidence, lethality, and post-stroke functional status in different Brazilian macro-regions: The SAMBA study (analysis of stroke in multiple Brazilian areas)

Background

Stroke is the second leading cause of death in Brazil. The social and financial burden of stroke is remarkable; however, the epidemiological profile remains poorly understood.

Objective

The aim of this study was to report the incidence, lethality, and functional status at 30 and 90 days post-stroke in the cities of different Brazilian macro-regions.

Methods

This is an observational, prospective, and population-based study, led in Canoas (South), Joinville (South, reference center), Sertãozinho (Southeast), and Sobral (Northeast) in Brazil. It was developed according to the three-step criteria recommended by the World Health Organization to conduct population-based studies on stroke. Using different sources, all hospitalized and ambulatory patients with stroke were identified and the same criteria were kept in all cities. All first events were included, regardless of sex, age, or type of stroke. Demographic and risk factor data were collected, followed by biochemical, electrocardiographic, and radiological test results. Functional status and lethality were obtained using the mRankin scale through telephonic interview (validated Brazilian version).

Results

In 1 year, 932 stroke cases were registered (784 ischemic stroke, 105 hemorrhagic stroke, and 43 subarachnoid hemorrhage). The incidence rates per 100,000 inhabitants, adjusted for the world population, were 63 in Canoas, 106 in Joinville, 72 in Sertãozinho, and 96 in Sobral. The majority (70.8%) were followed for 90 days. Kaplan-Meier curves showed that 90-day survival was different among cities. Sobral, which has the lowest socioeconomic indexes, revealed the worst results in terms of lethality and functional status.

Conclusion

This study expands the knowledge of stroke epidemiology in Brazil, a middle-income country with enormous socioeconomic and cultural diversity. The discrepancy observed regarding the impact of stroke in patients from Joinville and Sobral highlights the need to improve the strategic allocation of resources to meet the health priorities in each location.

Incidence and Severity of Intracerebral Hemorrhage on Oral Anticoagulation and Antiplatelet Therapy

Safety and efficacy of oral anticoagulation (OA) and antiplatelet therapy (AP) for cardiovascular prevention in Brazil are likely to be affected by economic and health access inequalities. This study aimed to assess the occurrence of intracerebral hemorrhage (ICH) in patients using OA or AP registered in the JOINVASC between 2015 and 2020. Higher mortality among OA or AP patients was seen, with a statistically significant difference in mortality within 90 days (38% versus 25%, p=0.025). For patients with OA at the time of ICH, high stroke severity was observed, with a 71% mortality rate. Managing bleeding episodes on OA and AP is key in the effort to prevent cardiovascular death and disability, and improved access to DOAC and reversal agents is in need for this patient population.

Ischemic stroke: Process perspective, clinical and profile characteristics, and external factors

OBJECTIVE

To describe a method of analysis for understanding the health care process, enriched with information on the clinical and profile characteristics of the patients. To apply the proposed technique to analyze an ischemic stroke dataset.

MATERIALS AND METHODS

We analyzed 4,830 electronic health records (EHRs) from patients with ischemic stroke (2010-2017), containing information about events realized during treatment and clinical and profile information of the patients. The proposed method combined process mining techniques with data analysis, grouping the data by primary care units (PCU - units responsible for the primary care of patients residing in a geographical area).

RESULTS

A novel method, named process, data, and management (PDM) analysis method was used for ischemic stroke data and it provided the following outcomes: health care process for patients with ischemic stroke with time statistics; analysis of potential factors for slow hospital admission indicating an increase in the time to hospital admission of 3.4 h (mean value) for patients with an origin at the urgent care center (UCC) - 30% of patients; analysis of PCUs with distinct secondary stroke rates indicating that the social class of patients is the main difference between them; and the visualization of risk factors (before the stroke) by the PCU to inform the health manager about the potential of prevention.

DISCUSSION

PDM analysis describes a step-by-step method for combining process analysis with data analysis considering a management focus. The results obtained on the stroke context can support the definition of more refined action plans by the health manager, improving the stroke health care process and preventing new events.

CONCLUSION

When a patient is diagnosed with ischemic stroke, immediate treatment is needed. Moreover, it is possible to prevent new events to some degree by monitoring and treating risk factors. PDM analysis provides an overview of the health care process with time, combining elements that affect the treatment flow and factors, which can indicate a potential for preventing new events. We also can apply PDM analysis in different scenarios, when there is information about activities from treatment flow and other characteristics related to the treatment or the prevention of the analyzed disease. The management focus of the results aids in the formulation of service policies, action plans, and resource allocation.

Decrease in Hospital Admissions for Transient Ischemic Attack, Mild, and Moderate Stroke During the COVID-19 Era

Since the onset of the coronavirus 2019 (COVID-19) pandemic, doctors and public authorities have demonstrated concern about the reduction in quality of care for other health conditions due to social restrictions and lack of resources. Using a population-based stroke registry, we investigated the impact of the onset of the COVID-19 pandemic in stroke admissions in Joinville, Brazil.

The cost of stroke in private hospitals in Brazil: a one-year prospective study

OBJECTIVE

Few studies from low- and middle-income countries have assessed stroke and cerebral reperfusion costs from the private sector. To measure the in-hospital costs of ischemic stroke (IS), with and without cerebral reperfusion, primary intracerebral hemorrhage (PIH), subarachnoid hemorrhage (SAH) and transient ischemic attacks (TIA) in two private hospitals in Joinville, Brazil.

METHODS

Prospective disease-cost study. All medical and nonmedical costs for patients admitted with any stroke type or TIA were consecutively determined in 2016-17. All costs were adjusted to the gross domestic product deflator index and purchasing power parity.

RESULTS

We included 173 patients. The median cost per patient was US$3,827 (IQR: 2,800-8,664) for the 131 IS patients; US$2,315 (IQR: 1,692-2,959) for the 27 TIA patients; US$16,442 (IQR: 5,108-33,355) for the 11 PIH patients and US$28,928 (IQR: 12,424-48,037) for the four SAH patients (p < 0.00001). For the six IS patients who underwent intravenous thrombolysis, the median cost per patient was US$11,463 (IQR: 8,931-14,291), and for the four IS patients who underwent intra-arterial thrombectomy, the median cost per patient was US$35,092 (IQR: 31,833-37,626; p < 0.0001). A direct correlation was found between cost and length of stay (r = 0.67, p < 0.001).

CONCLUSIONS

Stroke is a costly disease. In the private sector, the costs of cerebral reperfusion for IS treatment were three-to-ten times higher than for usual treatments. Therefore, cost-effectiveness studies are urgently needed in low- and middle-income countries.

The cost of stroke in a public hospital in Brazil: a one-year prospective study

OBJECTIVE

Low- and middle-income countries face tight health care budgets, not only new resources, but also costly therapeutic resources for treatment of ischemic stroke (IS). However, few prospective data about stroke costs including cerebral reperfusion from low- and middle-income countries are available. To measure the costs of stroke care in a public hospital in Joinville, Brazil.

METHODS

We prospectively assessed all medical and nonmedical costs of inpatients admitted with a diagnosis of any stroke or transient ischemic attack over one year, analyzed costs per type of stroke and treatment, length of stay (LOS) and compared hospital costs with government reimbursement.

RESULTS

We evaluated 274 patients. The total cost for the year was US$1,307,114; the government reimbursed the hospital US$1,095,118. We found a significant linear correlation between LOS and costs (r = 0.71). The median cost of 134 IS inpatients who did not undergo cerebral reperfusion (National Institutes of Health Stroke Scale [NIHSS] median = 3 ) was US$2,803; for IS patients who underwent intravenous (IV) alteplase (NIHSS 10), the median was US$5,099, and for IS patients who underwent IV plus an intra-arterial (IA) thrombectomy (NIHSS > 10), the median cost was US$10,997. The median costs of a primary intracerebral hemorrhage, subarachnoid hemorrhage, and transient ischemic attack were US$2,436, US$8,031 and US$2,677, respectively.

CONCLUSIONS

Reperfusion treatments were two-to-four times more expensive than conservative treatment. A cost-effectiveness study of the IS treatment option is necessary.

High five-year mortality rates of ischemic stroke subtypes: A prospective cohort study in Brazil

Background

Studies regarding long-term outcomes of ischemic stroke subtypes are scarce in low- and middle-income countries. We aimed to measure the five-year prognosis of ischemic stroke subtypes in Joinville, Brazil.

Methods

All first-ever ischemic strokes that occurred in Joinville in 2010 were followed-up for five years.

Results

We included 334 ischemic stroke patients. Over five years, 156 died, 51 had a recurrent stroke, and 128 were free of recurrent stroke. The overall cumulative risk of death was 17% (95% CI, 13% to 22%) at 30 days and 47% (95% CI, 41% to 52%) after five years. Undetermined with incomplete investigation ischemic stroke had a significantly worse survival probability (β −4.91; 95% CI, −6.31 to −3.50; p < 0.001), followed by cardioembolic ischemic stroke (β −3.07; 95% CI, −4.32 to −1.83; p < 0.001) and large artery disease ischemic stroke (β −1.95; 95% CI, −3.30 to −0.60; p = 0.005). The survival probability of undetermined with negative investigation or cryptogenic ischemic stroke did not differ significantly from small artery disease ischemic stroke (β −1.022; 95% CI, −3.37 to −1.43; p = 0.414). The five-year mortality for small artery disease ischemic stroke was 30% (95% CI, 22% to 39%) and 47% (95% CI, 35% to 60%) for large artery ischemic stroke. The risk of stroke recurrence was 2% in the first year and 5% in the second year. The proportion of disability among survivors in the first month ranged from 8% (95% CI, 3–15) for small artery disease ischemic stroke to 40% (95% CI, 30–52) for cardioembolic ischemic stroke patients.

Conclusions

Cardioembolic and undetermined with incomplete investigation ischemic stroke sub-types have a poor long-term prognosis. An alarming finding was that our patients with both small and large artery ischemic stroke had higher five-year mortality rates compared with subjects from high-income countries.

Prevalence of obesity among stroke patients in five Brazilian cities: a cross-sectional study

ABSTRACT Objective There is gap in knowledge about obesity prevalence in stroke patients from low- and middle-income countries. Therefore, we aimed to measure the prevalence of overweight and obesity status among patients with incident stroke in Brazil. Methods In a cross-sectional study, we measured the body mass index (BMI) of ischemic and hemorrhagic stroke patients. The sample was extracted in 2016, from the cities of Sobral (CE), Sertãozinho (SP), Campo Grande (MS), Joinville (SC) and Canoas (RS). Results In 1,255 patients with first-ever strokes, 64% (95% CI, 62–67) were overweight and 26% (95%CI, 24–29) were obese. The obesity prevalence ranged from 15% (95%CI, 9–23) in Sobral to 31% (95%CI, 18–45) in Sertãozinho. Physical inactivity ranged from 53% (95%CI, 43-63) in Sobral to 80% (95%CI, 73–85) in Canoas. Conclusions The number of overweight patients with incident stroke is higher than the number of patients with stroke and normal BMI. Although similar to other findings in high-income countries, we urgently need better policies for obesity prevention.

Five-year survival, disability, and recurrence after first-ever stroke in a middle-income country: A population-based study in Joinvile, Brazil

Background Information about long-term outcomes after stroke in developing countries provided by population-based methodologies is scarce. Aim This study aimed to know outcomes five years after a first-ever stroke in Joinville, Brazil. Methods Data were extracted from the Joinville Stroke Registry about all patients who had strokes in Joinville in 2010 and were followed up to 2015. Stroke recurrence, Kaplan-Meier survival probabilities, functional outcomes, and causes of death were ascertained at 30 days, six months, one and five years. Results A total of 399 strokes were studied. The mean age was 64 (standard deviation 16) years. After five years, 52% (95% confidence interval: 47-57%) survived and 20% (95% confidence interval: 15-26%) of the survivors had modified Rankin scale scores >2. More than half of these patients were institutionalized in nursing or home care settings. The average risk of death per year was ≈7%. Survival rates were significantly lower for subarachnoid hemorrhage and primary intracerebral hemorrhage than for ischemic stroke. The five-year recurrence rate was 12% (95% confidence interval: 9-15%). The index stroke was the cause of death in three quarters of the patients. Conclusions The results showed that 68% of the patients with stroke were either dead or disabled five years after first-ever stroke. This percentage is similar to proportions of other recent cohorts from developed countries, despite the lower age of the patients in this study.

Joinville stroke biobank: study protocol and first year’s results

ABSTRACT Aiming to contribute to studies that use detailed clinical and genomic information of biobanks, we present the initial results of the first Latin American Stroke Biobank. Methods: Blood samples were collected from patients included in the Joinville Stroke Registry and four Brazilian cities. Demographic socio-economic data, cardiovascular risk factors, Causative Classification System for Ischemic Stroke, Trial of Org 10172 in Acute Stroke Treatment and National Institutes of Health scores, functional stroke status (modified Rankin) and brain images were recorded. Additionally, controls from both geographic regions were recruited. High-molecular-weight genomic DNA was obtained from all participants. Results: A total of 2,688 patients and 3,282 controls were included. Among the patients, 76% had ischemic stroke, 12% transient ischemic attacks, 9% hemorrhagic stroke and 3% subarachnoid hemorrhage. Patients with undetermined ischemic stroke were most common according the Trial of Org 10172 in Acute Stroke Treatment (40%) and Causative Classification System for Ischemic Stroke (47%) criteria. A quarter of the patients were under 55 years of age at the first-ever episode. Conclusions: We established the Joinville Stroke Biobank and discuss its potential for contributing to the understanding of the risk factors leading to stroke.

Incidence and functional outcome of atrial fibrillation and non-atrial fibrillation- related cardioembolic stroke in Joinville, Brazil: a population-based study

ABSTRACT Among ischemic strokes, cardioembolic (CE) stroke has the worst outcome. We measured the incidence of atrial fibrillation (AF) and non-AF related CE strokes, previous anticoagulant use, and the 90-day functional outcome. Using multiple overlapping sources, we included all CE strokes that occurred in 2015 in Joinville, Brazil. Of the 374 ischemic strokes, 23% (84) were CE. The CE age-adjusted incidence, per 1,000 person-years, was 0.14 (0.11–0.17). Of the 26 patients with known prior AF, 73% (19) were not anticoagulated, 77% (20) had a CHA2DS2VASc score ≥ 3 and 81% (21) had a HAS-BLED score < 3. After three months, approximately one third of those 26 patients died or became disabled. The incidence of CE stroke in our sample was lower than in other population-based studies. The opportunity for anticoagulation was missed in one third of cases.

Intravenous rtPA versus mechanical thrombectomy in acute ischemic stroke: A historical cohort in Joinville, Brazil

Groundbreaking results concerning ischemic stroke (IS) hyperacute treatment worldwide were published in 2014 and 2015. We aimed to compare functional status after 3 months in patients treated with intra-arterial thrombectomy (IAT) and those treated with intravenous thrombolysis (IVT) alone in Joinville, Brazil.

From the Joinville Stroke Registry, we extracted and compared all consecutive IVT patients treated with r-tPA within 4.5 h in the period 2009–2011 versus all consecutive IAT treated within 6 h with the Solitaire FR device plus IVT in the period 2012–2014.

We registered 82 patients in the IVT group and 31 patients in the IAT group. At hospital admission, patients in the IAT group were significantly younger (p < 0.001), had a higher educational level (p = 0.001), had a slightly higher prevalence of atrial fibrillation (p = 0.057) and had more severe strokes measured by the NIH stroke scale (p = 0.011). After 90 days, 45% of patients in the IAT group and 27% in the IVT group were independent (0–1 points) according to the modified Rankin scale (adjusted odds ratio: 4.53; 95% CI: 1.22 to 16.75). Symptomatic hemorrhage was diagnosed in 10% of patients in both groups (p = 1.0). The 90-day case-fatality was 39% (32/82) in the IVT group and 26% (8/31) in the IAT group (p = 0.27). In this small cohort, a greater rate of functional independence was achieved in patients treated with IAT plus IVT, compared with patients treated with IVT lysis alone. Our “real-world” findings are consistent with results of controlled, randomized clinical trials.

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Incidence of ischemic stroke have been increasing in low and middle income countries ( LMIC) over last 3 decades.

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Combined intravenous – endovascular approach opened a new era in treatment of ischemic stroke with absolute risk reduction of functional dependency.

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How far these data might be translated to LMIC settings?

Trends of Stroke Incidence from 1995 to 2013 in Joinville, Brazil

BACKGROUND

Temporal trends on the incidence of stroke and its subtypes could help assess on-going public health policies and point to further targets for action among middle- and low-income countries, where the stroke burden is very high. This study aimed at evaluating longitudinal trends of stroke incidence in Joinville, Brazil.

METHODS

We ascertained the incidence of all first-ever strokes occurred in 1995, 2005-2006 and 2012-2013, which were extracted from Joinville Stroke Registry, a prospective epidemiological data bank, launched in 1995.

RESULTS

From 1995 to 2013, the age-adjusted incidence of all strokes decreased 37% (95% CI 32-42). From 2005 to 2013, the haemorrhagic stroke (HS) incidence decreased 60% (95% CI 13-86), ischemic stroke (IS) incidence decreased 15% (95% CI 1-28), and subarachnoid haemorrhage incidence remained stable. The proportion of IS and HS patients with regularly treated hypertension increased by 60% (p = 0.01) and 33% (p = 0.01), respectively. The proportion of IS and HS patients that quit smoking increased 8% (p = 0.03) and 17% (p = 0.03), respectively.

CONCLUSIONS

Stroke incidence has been decreasing in Joinville over the last 18 years, more so for HS than IS. Better control of hypertension and tobacco use might explain these findings.

Three-year survival and recurrence after first-ever stroke: the Joinville stroke registry

Background

Data estimating the recurrence and risk of death are lacking in low and middle income countries, where two thirds of the stroke burden occurs. Previously we had shown that the incidence and mortality have been decreasing over the last 18 years in Joinville, Southern Brazil. In this study, we aim to determine the recurrence rates, survival rates and the cause of death in 3 years after their first-ever incident in a urban population-based setting.

Methods

From the Joinville Stroke Registry, we identified all the cases of first-ever stroke that occurred from October 2009 to September 2010. Multiple overlapping sources of information were used to ensure the completeness of case identification. Patients were followed up prospectively at regular intervals from 30-days to 3 years after the index event. Kaplan-Meir and Cox proportional hazards were used to assess the cumulative risk of death and recurrence.

Results

We registered 407 first-ever stroke patients. After 3 years, 136 (33%) had died. In the first year of stroke the risk of death was 28% (95% CI, 25 to 32). Beyond the first year, approximately 3 to 5% of survivors died each year. The cumulative risk of death in ischemic stroke (IS) subtypes was 3.6 higher for cardioembolic (CE) IS (hazard ratio 3.6, 95% CI, 2.1 to 6.4; p = 0.001) and 3.3 times higher for undetermined IS (HR 3.3, 95% CI 1.9 to 5.8; p = 0.001) compared to small artery occlusion IS. Over 3 years, the overall stroke recurrence risk was 9% (35/407). We found no difference in stroke recurrence risk between IS subtypes. Cardiovascular disease was the main cause of death all follow up time.

Conclusions

Compared to other cohort studies conducted between 10 and 20 years ago in high-income countries, our recurrence rates and 3-year risk of death were similar. Among IS subtypes, we confirmed that CE has highest risk of death. The most common cause of death after a first-ever stroke is cardiovascular disease. This has implications for the uptake of current secondary preventive strategies and the development of new strategies.

Trends of the Incidence of Ischemic Stroke Thrombolysis over Seven Years and One-Year Outcome: A Population-Based Study in Joinville, Brazil

Background

In a population-based setting, we aimed to measure the incidence trends of ischemic stroke (IS) thrombolysis, thrombolysis times, proportion of symptomatic intracerebral hemorrhage (sICH), 30-day case fatality and functional outcomes. We also compared the 12-month functional status between thrombolyzed and nonthrombolyzed patients.

Methods

Using data from the Joinville Population-Based Stroke Registry, we prospectively ascertained a cohort of all thrombolyses done in Joinville citizens, Southern Brazil, from 2005 to 2011. For the definition of sICH we used European Cooperative Acute Stroke Study (ECASS) II criteria.

Results

Over 7 years, 6% (220/3,552) of all IS were thrombolyzed. The thrombolysis incidence increased from 1.4 [95% confidence interval (CI), 0.6-2.9] in 2005 to 9.8 (7.3-12.9) per 100,000 population in 2011 (p < 0.0001). The thrombolysis incidence age-adjusted to the world population in 2011 was 11 (8.2-14.3) per 100,000. Only 30% (50/165) were thrombolyzed within 1 h of arrival at hospital. In 7 days, 6.4% (14/220) had sICH and 57% (8/14) of those died. In the 2009-2011 period, a favorable functional outcome [modified Rankin scale (mRS) 0-1] at 12 months among patients who received thrombolysis was more frequent [mRS 0-1; 36% (38/107)] than among patients who did not receive thrombolysis [mRS 0-1; 24% (131/544); p = 0.016]. The logistic regression showed that thrombolyzed IS patients had a more favorable outcome (mRS 0-1; HR 2.13; 95% CI, 1.2-3.7; p < 0.016) than nonthrombolyzed patients.

Conclusion

In a population setting of a middle income country, the thrombolysis incidence and outcomes were similar to those of other well-structured services. After 1 year, patients thrombolyzed in the 4.5-hour time window had a better outcome. More than proportions, rates provide additional information and could be used to benchmark services against others.

[The application of external knee stabilizers - Influence on mechanical stabilization and physical performance]

The aim of the study was, to assess the influence of a knee brace on the development of anterior instability after anterior cruciate ligament rupture and to test aptitude for physical strain. 46 subjects with arthroscopically proven anterior cruciate ligament rupture were divided equally in a randomised order into two groups. Both groups carried out a standardized physical therapy program, while one group (0) received additional stabilization by means of a functional knee brace (SofTec, Bauerfeind). In addition, important features of the brace (stabilization capacity, safety perception and physical performance) were tested and compared to the non-braced contralateral leg among 23 healthy physical education students by means of a standardized scaled questionnaire (observational study). 0 showed lower (p < 0.05) development of the anterior instability by 46 % and lower (p < 0.05) reduction in circumference of the femur muscles by 25 %. Increasing the time interval between accident and beginning of the brace treatment, increased the difference of the therapeutical effect of the brace. In the observational study, the brace received a better evaluation regarding all test parameters. The reduction of developing anterior instability by means of a brace should facilitate - apart from an individual operation-time-arrangement - especially a conservative approach within the framework of anterior instability and physical activity. Aside from the improvement of the mechanical stabilization, indications for suitability in strain situations could be detected for the tested brace.

Photochemical and photobiological studies with acridine and phenanthridine hydroperoxides in cell-free DNA

The acridine and phenanthridine hydroperoxides 3 and 7 were synthesized as photochemical hydroxyl radical sources for oxidative DNA damage studies. The generation of hydroxyl radicals upon UVA irradiation (lambda = 350 nm) was verified by trapping experiments with 5,5-dimethyl-1-pyrroline N-oxide and benzene. The enzymatic assays of the damage in cell-free DNA from bacteriophage PM2 caused by the acridine and phenanthridine hydroperoxides 3 and 7 under near-UVA irradiation revealed a wide range of DNA modifications. Particularly, extensive single-strand break formation and DNA base modifications sensitive to formamidopyrimidine DNA glycosylase (Fpg protein) were observed. In the photooxidation of calf thymus DNA, up to 0.69 +/- 0.03% 8-oxo-7,8-dihydroguanine was formed by the hydroperoxides 3 and 7 on irradiation, whose yield was reduced up to 40% in the presence of the hydroxyl radical scavengers mannitol and tert-butanol. The acridine and phenanthridine hydroperoxides 3 and 7 also induce DNA damage through the type I photooxidation process, for which photoinduced electron transfer from 2'-deoxyguanosine to the singlet states of 3 and 7 was estimated by the Rehm-Weller equation to possess a negative Gibb's free energy of ca -5 kcal/ mol. Control experiments with the sensitizers acridine 1 and the acridine alcohol 4 in calf thymus and PM2 DNA confirmed the photosensitizing propensity of the UVA-absorbing chromophores. The present study emphasizes that for the development of selective and efficient photochemical hydroxyl radical sources, chromophores with low photosensitizing ability must be chosen to avoid type I and type II photooxidation processes.

[Blood group specific properties of leucocyte nuclei (author's transl)]

The absorbing and precipitating capacity of leucocyte nuclear suspensions derived from conserved blood of various blood groups was examined with anti-A-, anti-B-, anti-H, anti-M-, anti-N-, and anti-CDE-, and anti-D-sera as well as with anti-AHP- and Evonymus-extracts. Nuclei of blood group A absorbed anti-A, but not anti-B; nuclei of blood group B absorbed anti-B, but not anti-A. Nuclei of blood group 0 absorbed anti-H, but neither anti-A nor anti-B. Anti-M-, anti-N-, anti-CDE-, and anti-D-sera showed no absorption effect after incubation with leucocyte nuclei of corresponding blood groups. A nuclei were strongly precipitated by anti-AHP; B- and 0-nuclei were markedly precipitated by Evonymus-extract. B- and 0-nuclei showed only a weak precipitation with anti-AHP-extract; A-nuclei were only slightly precipitated by Evonymus-extract. Hence, leucocyte nuclei possess blood group specific properties, which, according to the present studies, are limited to certain blood group systems.