Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Edoxaban versus placebo, aspirin, or aspirin plus clopidogrel for stroke prevention in atrial fibrillation. An indirect comparison analysis

As non-valvular atrial fibrillation (AF) brings a risk of stroke, oral anticoagulants (OAC) are recommended. In 'real world' clinical practice, many patients (who may be, or perceived to be, intolerant of OACs) are either untreated or are treated with anti-platelet agents. We hypothesised that edoxaban has a better net clinical benefit (NCB, balancing the reduction in stroke risk vs increased risk of haemorrhage) than no treatment or anti-platelet agents. We performed a network meta-analysis of published data from 24 studies of 203,394 AF patients to indirectly compare edoxaban with aspirin alone, aspirin plus clopidogrel, and placebo. Edoxaban 30 mg once daily significantly reduced the risk of all stroke, ischaemic stroke and mortality compared to placebo and aspirin. Compared to aspirin plus clopidogrel, there was a lower risk of intra-cranial haemorrhage (ICH). Edoxaban 60 mg once-daily had a reduced risk of any stroke and systemic embolism compared to placebo, aspirin, and aspirin plus clopidogrel. Mortality rates for both edoxaban doses were estimated to be lower compared to any anti-platelet, and significantly lower compared to placebo. With overall reduced risk of ischemic stroke and ICH, both edoxaban doses bring a NCB of mean (SD) 1.68 (0.15) saved events per 100 patients per year compared to anti-platelet drugs in a clinical trial population. The NCB was demonstrated to be lower, at 0.77 (0.12) events saved (p< 0.01) when modeled to data from a 'real world' cohort of AF patients. In conclusion, edoxaban is likely to provide even better protection from stroke and ICH than placebo, aspirin alone, or aspirin plus clopidogrel in both clinical trial populations and unselected community populations. Both edoxaban doses would also bring a positive NCB compared to anti-platelet drugs or placebo/non-treatment based on 'real world' data.

Dabigatran adherence in atrial fibrillation patients during the first year after diagnosis: a nationwide cohort study

BACKGROUND

There is a perception among physicians that lack of routine monitoring with non-vitamin K antagonist oral anticoagulants (NOACs) may lead to poor adherence to medication. We studied adherence during the first year of usage in a cohort of patients with newly diagnosed non-valvular atrial fibrillation (AF) started on the NOAC, dabigatran etexilate.

METHODS AND RESULTS

Nationwide Danish patient and prescription purchase registries were used to identify newly diagnosed AF patients taking dabigatran, comorbidities, and refill patterns under a twice-daily, one pill regimen. Adherence was characterized among remaining users (N = 2960) after 1 year using the proportion of days covered (PDC), gap rates and restart rates. The overall 1-year PDC was 83.9%, with 76.8% of patients having a 1-year PDC in excess of 80%. Patients with a CHA2 DS2 -VASc score ≥ 2 were more adherent to medication regimes than patients with a CHA2 DS2 -VASc score of 1 (PDC ratio, 1.12; 95% confidence interval [CI], 1.08-1.17) and generally patients with higher morbidity showed more adherence. Patients with prior bleeding were not less adherent to medication regimes than patients with no prior bleeding (PDC ratio, 1.02; 95% CI, 0.98-1.06). The overall gap rate was 1.4 gaps per year. There were no clear tendencies in gap rates among subgroups, although patients with higher morbidity tended to have slightly more, but shorter, gap periods.

CONCLUSIONS

More than 75% of patients were showed > 80% adherence to medication regimes during the first year. Patients with higher morbidity, including patients with a higher risk of stroke or bleeding, exhibited better adherence. This improvement may be attributable to more regular contact with the healthcare system.

Randomized clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins

BACKGROUND

This randomized trial compared four treatments for varicose great saphenous veins (GSVs).

METHODS

Five hundred consecutive patients (580 legs) with GSV reflux were randomized to endovenous laser ablation (980 and 1470 nm, bare fibre), radiofrequency ablation, ultrasound-guided foam sclerotherapy or surgical stripping using tumescent local anaesthesia with light sedation. Miniphlebectomies were also performed. The patients were examined with duplex imaging before surgery, and after 3 days, 1 month and 1 year.

RESULTS

At 1 year, seven (5.8 per cent), six (4.8 per cent), 20 (16.3 per cent) and four (4.8 per cent) of the GSVs were patent and refluxing in the laser, radiofrequency, foam and stripping groups respectively (P < 0.001). One patient developed a pulmonary embolus after foam sclerotherapy and one a deep vein thrombosis after surgical stripping. No other major complications were recorded. The mean(s.d.) postintervention pain scores (scale 0-10) were 2.58(2.41), 1.21(1.72), 1.60(2.04) and 2.25(2.23) respectively (P < 0.001). The median (range) time to return to normal function was 2 (0-25), 1 (0-30), 1 (0-30) and 4 (0-30) days respectively (P < 0.001). The time off work, corrected for weekends, was 3.6 (0-46), 2.9 (0-14), 2.9 (0-33) and 4.3 (0-42) days respectively (P < 0.001). Disease-specific quality-of-life and Short Form 36 (SF-36(®)) scores had improved in all groups by 1-year follow-up. In the SF-36(®) domains bodily pain and physical functioning, the radiofrequency and foam groups performed better in the short term than the others.

CONCLUSION

All treatments were efficacious. The technical failure rate was highest after foam sclerotherapy, but both radiofrequency ablation and foam were associated with a faster recovery and less postoperative pain than endovenous laser ablation and stripping.

Impact of vascular disease in predicting stroke and death in patients with atrial fibrillation: the Danish Diet, Cancer and Health cohort study

BACKGROUND

The presence of vascular disease (peripheral artery disease [PAD] and/or myocardial infarction [MI]) may impact on the risk of stroke and death among patients with incident atrial fibrillation (AF). To test this hypothesis, we analyzed data from a large Danish prospective cohort, the Danish Diet, Cancer and Health (DCH) study, to assess the risk of stroke or death among those who developed AF according to concomitant presence of vascular disease.

METHODS

A prospective cohort study of 57, 053 persons (27, 178 men and 29, 876 women, respectively), aged between 50 and 64 years. The risk of stroke or death for patients with vascular disease was assessed amongst 3315 patients with incident AF (mean age, 67.1years; 2130 men, 1185 women) using Cox proportional hazard models, after a median follow-up of 4.8 years.

RESULTS

 Of the subjects with AF, 417 (12.6%) had 'vascular disease' (PAD and/or prior MI). The risk of the primary endpoint (stroke or death) was significantly higher in patients with vascular disease at 1-year follow-up (crude hazard ratio [HR] 2.51 [1.91-3.29]), with corresponding crude HRs for PAD and MI being 3.51 (2.40-5.13), and 1.99 (1.46-2.72), respectively. For the secondary endpoints of death or stroke individually, these risk estimates were similar (crude HR 2.48 [1.89-3.26] and 1.77 [1.18-2.66], respectively). After adjustment for risk factors within the CHADS(2) score, the adjusted HR for the primary endpoint (stroke or death) in patients with vascular disease was 1.91 (1.44-2.54), which was also significant for death (1.97 [1.48-2.62]).

CONCLUSION

Vascular disease (prior MI and PAD) is an independent risk factor for the primary endpoint of 'stroke or death' in patients with AF, even after adjustment for the CHADS(2) risk score, although this is driven by the impact on mortality. This reaffirms that patients with vascular disease represent a 'high-risk' population, which necessitates proactive management of all cardiovascular risk factors and effective thromboprophylaxis (i.e. oral anticoagulation), which has been shown to significantly reduce the risk of stroke and death in AF.

The relationship between QTc changes and nutrition during weight loss after gastroplasty

Electrocardiograms, serum electrolytes, plasma concentrations of pre-albumin and retinol-binding globulin, and dietary intakes were analyzed in 22 women during weight loss after gastroplasty surgery for morbid obesity. QT interval corrected for heart rate (QTc) was prolonged (greater than 0.44 sec) in 32% (95% confidence limits 14-55%) on one or more occasions. No clinical or electrocardiographic complications were seen. Occurrence of QTc prolongation was significantly (p less than 0.05) associated with protein intake below recommendation and with low plasma pre-albumin concentrations. QTc prolongation was not associated with mineral intake and occurred in spite of normal serum levels of calcium (uncorrected and albumin-corrected), magnesium, potassium and sodium. Because QTc prolongation may precede fatal arrhythmias, adequate protein intake is mandatory during weight reduction.

[Abciximab (ReoPro) in the treatment of acute coronary syndromes]

Platelet activation plays a major role in the pathophysiology of acute coronary syndromes (ACS). Inhibition of platelet function is the basic pharmacological treatment of ACS. Platelet membrane glycoprotein IIb/IIIa inhibitors, a new class of potent antiplatelet agents, have been used in the treatment of ACS and in the prevention of complications after percutaneous coronary interventions (PCI). Several large clinical trials have demonstrated the effectiveness of this class of agents. The first of these agents to show beneficial effects after coronary interventions was the mouse/human chimeric Fab fragment antibody c7E3 abciximab (ReoPro). The purpose of this article is to describe the pharmacology of abciximab and to review the results of the clinical trials carried out with the drug in patients with ACS, treated either with or without acute/elective PCI.

[Clinical studies on glycoprotein IIb/IIIa receptor antagonist]

Platelet activation plays a major role in the pathophysiology of acute coronary syndromes (ACS), and inhibition of platelet function is the basic pharmacological treatment of ACS. Platelet membrane glycoprotein IIb/IIIa inhibitors, a new class of potent antiplatelet agents, have been used in the treatment of ACS, as well as in the prevention of complications after percutaneous coronary interventions. The aim of this article is to describe the potential possibilities of platelet inhibition and to review the pharmacology of glycoprotein IIb/IIIa inhibitors, the results of the clinical trials with these agents, and their current use in the pharmacological treatment of ACS and in relation to percutaneous coronary intervention.

[Parvovirus B19 infection as the cause of hepatitis and neutrophil granulocytosis in a 20-year old woman]

A case of Parvovirus B19 infection (erythema infectiosum) in a 20 year old woman is presented. The patient presented with fever, arthritis in one knee, neutrophil granulocytosis and biochemical evidence of hepatitis. Serological evidence of Parvovirus B19 infection was found as the only explanation of the clinical picture. Hepatitis was due to Parvovirus B19 infection as there was no serological evidence of EBV or CMV reactivation. Neutrophil granulocytosis and thrombocytosis were found and were probably due to an active bone marrow in the recovery phase of bone marrow aplasia.

Dose response profiles of human growth hormone in subcutaneous wound chambers in rats

OBJECTIVE

To investigate dose response profiles of human growth hormone in soft connective tissue healing when it is given locally in subcutaneous wound chambers.

DESIGN

Placebo controlled parallel study.

SETTING

Institute of Medical Anatomy, Denmark.

MATERIAL

36 male Sprague Dawley rats, in three group of 12.

INTERVENTIONS

Stainless steel wire mesh cylinders 7 mm in diameter and 20 mm long were implanted subcutaneously in pairs in the upper and lower back on either side of the midline in three groups of male Sprague Dawley rats. Two groups were each given two different doses of growth hormone (group 1, 0.2 and 0.7 IU; and group 2, 0.02 and 2 IU) in two cylinders and vehicle alone in the two cylinders on the opposite side. Group 3 were given vehicle alone in two cylinders and needle puncture (sham) on the opposite side. Injections of growth hormone or vehicle (placebo) were given every three days for 16 days.

MAIN OUTCOME MEASURES

Body weight, weight of granulation tissue, and concentrations of hydroxyproline and aminoterminal propeptide of procollagen type III.

RESULTS

The dose response curves for weight of granulation tissue and deposition of collagen were upward convex (ANOVA p < 0.001 and 0.001, respectively). Growth hormone in doses of 0.2 and 0.7 IU stimulated formation of granulation tissue to means of 180% (95% confidence interval (Cl) 149% to 210%) and 174% (95% Cl 148% to 200%) more than in the placebo treated cylinders (group 3) (p < 0.05 and < 0.01, respectively). Doses of 0.2 and 2 IU, however, had less effect. The placebo cylinders in animals in groups 1 and 2 contained a mean of 157% (95% Cl 137% to 177%) more granulation tissue than the cylinders in group 3, indicating that locally applied growth hormone also had a systemic effect.

CONCLUSION

The clinical use of topical growth hormone in wound healing may be complicated by the relatively narrow therapeutic interval.

Influence of human growth hormone on granulation tissue formation, collagen deposition, and the aminoterminal propeptide of collagen type III in wound chambers in rats

The influence of growth hormone on granulation tissue formation was investigated in wire mesh cylinders implanted subcutaneously in rats. Two groups of 10 rats (study 1) and 1 group of 12 rats (study 2) were used for the investigation. Growth hormone, 0.02 and 0.2 IU (study 1), 0.05 and 0.2 IU (study 2), or vehicle only, was injected into the cylinders every third day for 16 days. In study 2, wound fluid was aspirated before injection of growth hormone and saved for later analysis of the aminoterminal propeptide of collagen type III. In both studies, growth hormone significantly increased the formation of granulation tissue and of total collagen content dose-dependently, whereas the relative amount of collagen was unaffected by growth hormone treatment. Wound fluid aminopropeptide increased significantly after implantation of the cylinders until day 7, before declining slightly, with no difference between the groups. We conclude that growth hormone stimulated granulation tissue formation and collagen deposition dose-dependently in the wound cylinders when injected every third day. The results suggest that growth hormone treatment does not cause excessive collagen deposition in newly formed granulation tissue.

The reference range for complexed alpha 2-macroglobulin human plasma: development of a new enzyme linked in immunosorbent assay (ELISA) for quantitation of complexed alpha 2-macroglobulin

Purified alpha 2-macroglobulin was complexed by reaction with methylamine and used to raise monoclonal murine antibodies. A four-step enzyme linked immunosorbent assay (ELISA) was developed to determine the antibody-specificity of the produced monoclonal murine antibodies towards human native and complexed alpha 2-macroglobulin. Two monoclonal antibodies were selected, H11A11 (specific towards complexed alpha 2-macroglobulin) and 1CG4 (recognizes both forms of the molecule), and purified by affinity chromatography on protein G. The purified antibodies were used to develop a fast three-step ELISA for exact quantitation of complexed and total alpha 2-macroglobulin in human plasma. The intra-assay coefficient of variation (CV) for measurement of complexed alpha 2-macroglobulin is 2.2-9.9%, whereas the inter-assay CV was determined to be 3.7-10.5% and the recovery of the assay is 93-108%. The assay for total alpha 2-macroglobulin has an intra-assay CV of 3.0-15.5%, an interassay CV of 5.1-21.2% and a recovery of 91-116%. Citrated plasma samples from 139 healthy blood donors were examined, resulting in a reference range for complexed alpha 2-macroglobulin of 13.5-31.1 mg 1(-1) with a median value of 21.7 mg 1(-1). The concentration of total alpha 2-macroglobulin was measured by the same assay using the monoclonal antibodies 1CG4. For total alpha 2-macroglobulin we determined the reference range to be 1.12-3.54 g 1(-1) with a median value of 2.14 g 1(-1). Based on these results the reference range for complexed alpha 2-macroglobulin as a percentage of total alpha 2-macroglobulin was calculated to be 0.8-1.9% with a median value of 1.0%.

Effect of meal frequency on blood glucose, insulin, and free fatty acids in NIDDM subjects

OBJECTIVE

We studied the effects of meal frequency on blood glucose, serum insulin, and FFAs in 12 NIDDM subjects.

RESEARCH DESIGN AND METHODS

Subjects were assigned in random order to two 8-hr observation periods after an overnight fast. They received isocaloric diets with similar composition either as six small or as two large meals. At the end of each study period, an IVGTT was given.

RESULTS

Two large meals induced an 84% greater maximum amplitude of glucose excursions than six small meals (6.1 +/- 0.5 vs. 3.3 +/- 0.5 mM, P < 0.005) and higher insulin responses (P < 0.03). The Kg response to an IVGTT did not differ in the two situations. The average FFA level was lowest in response to frequent meals (P < 0.02).

CONCLUSIONS

A higher meal frequency acutely subdues glucose excursions and reduces insulin and FFA levels during the daytime in older NIDDM subjects.

Collagen types I and III propeptides as markers of healing in chronic leg ulcers. A noninvasive method for the determination of procollagen propeptides in wound fluid--influence of growth hormone

A noninvasive method allowing measurements of the propeptides of collagen type III (PIIINP) and type I (PICP) in ulcer washings was developed. The response to topical human growth hormone was examined. Fourteen patients with venous ulcers were treated sequentially with human growth hormone (0.1, 0.25, and 1 IU/cm2/day), each dose for 1 week, followed by 1 week washout. On alternate days, three and two times during treatment and washout periods, respectively, the ulcers were washed and incubated for 30 minutes with sterile water. No changes in healing rates in relation to growth hormone application were observed. In contrast, PIIINP increased significantly to 168% (154% to 184%) (mean, 95% confidence interval) and 195% (179% to 218%) 5 and 9 days, respectively, after start of treatment, (p < 0.01). Propeptides of collagen type I reached a significant increase, to 196% (172% to 232%), in the fourth week, (p < 0.01). The areas under the curves of PICP and PIIINP correlated significantly with the healing rates (r = 0.57, p = 0.04; and r = 0.64, p = 0.01, respectively). The authors conclude that propeptide measurements may be useful markers of healing in clinical studies.

[Growth hormone and surgery]

Development of biosynthetic human growth hormone (b-hGH) may be a beneficial supplement in the treatment of surgical patients with major traumas in future. As a result of its anabolic actions, b-hGH has proved to be protein conserving in patients who have undergone major gastrointestinal operations with a net decrease in urinary protein excretion, increased fat oxidation and preservation of grip strength and lean body mass. In addition, animal experiments have shown a pronounced stimulatory effect on the healing of tibial fractures in both young and old rats and in the healing of colon anastomoses, as evaluated from the biomechanical properties of the tissues. Experimental skin wounds have also been shown to benefit from b-hGH treatment but only in the early phases of the healing process. Studies on woundhealing in humans have revealed beneficial effects of b-hGH on donor-site healing in skin grafting of patients with severe burns on systemic administration and on healing of chronic leg ulcers on topical application. Further studies in humans with characterization of patients who may benefit from the treatment and the dose-response relations are required to evaluate possible employment of growth hormone in surgical practice.

Risk of bilateral testicular germ cell cancer in Denmark: 1960-1984

The incidence of a second primary testicular germ cell cancer among 2850 (96.6% of eligible) men with a histologically verified first primary germ cell cancer diagnosed in the period 1960-1979 in Denmark was established. Of these 2850 men, 73 (2.6%) developed a contralateral testicular cancer. In five of these patients (0.18%), the tumors were synchronous. The cumulative risk of developing a contralateral cancer 25 years after diagnosis of the first testicular germ cell cancer was 5.2% according to a Kaplan-Meier estimate. It was higher among men with a nonseminoma as the first tumor (8.4%) than among men with a seminoma as the first tumor (3.6%). Of the second tumors, 12% were stage II and 17% were stage III at the time of diagnosis. Based on 24,588 person-years at risk and 68 nonsimultaneously occurring bilateral testicular germ cell cancers, the overall relative risk (RR) of developing a second primary cancer in the contralateral testicle following a first germ cell cancer was found to be 24.8 (95% confidence interval = 19-38). Among men with a nonseminoma, the risk was higher (RR = 27.1) than among men with a seminoma (RR = 22.5). The excess risk was not affected by age at diagnosis, calendar period, or time since diagnosis. Close surveillance by screening for and treatment of carcinoma in situ of the remaining testicle in testicular cancer patients are advised.

[Acute severe polyneuropathy in hepatic porphyria]

Two cases of acute polyneuropathy in patients with latent hepatic porphyria are presented. Porphyric neuropathy is a rare, serious, life-threatening disease. Since most cases are induced by drugs, early diagnosis is essential for the treatment and prognosis. Porphyria should always be considered in acute polyneuropathy.

Protein kinase C subtypes in human neutrophils

Protein kinase C from rat brain and human neutrophils was chromatographically separated on a hydroxylapatite column connected to a high-performance liquid chromatography (HPLC) system. Protein kinase C from rat brain was separated into three peaks (types I, II, and III). In contrast, only two types were obtained from human neutrophils matching type II and type III in brain. In cell membranes from unstimulated human neutrophils type III was predominant, but mainly type II was translocated to the membranes upon stimulation with phorbolmyristatacetate (PMA). Both types were equivalently activated by phosphatidylserine, diolein, and magnium and presented identical Km for ATP.

Authentic recombinant human growth hormone. Results of a multicenter clinical trial in patients with growth hormone deficiency

197 patients with growth hormone deficiency (144 boys, 53 girls, age 1.5-19.5 [mean 11 +/- 3.6], bone age 0.3-15 [mean 8.9 +/- 3.5] years) were treated for one year with authentic recombinant human growth hormone (r-hGH, Norditropin] in several European paediatric centers. 107 patients were newly treated (group A), and 90 transferred from pituitary or methionine hGH (groups B and C). In 19 of the latter, treatment was interrupted for 6 months (group B), in the others, it was changed without interruption (group C). The dosage was 0.45 +/- 0.2 IU/kg/week given s.c. 6-7 times a week. Height velocity increased from 4.1 +/- 2.4 to 8.3 +/- 2.5 (group A), 2.6 +/- 1.8 to 8.3 +/- 2.3 (group B), and 6.2 +/- 2.7 to 6.8 +/- 2.2 cm/year (group C). Few patients complained of local discomfort at the injection site, but this disappeared after changing metacresol in the solvent to 0.9% benzyl alcohol. Only 3 patients developed antibodies to hGH in low titers, which did not interfere with growth. No changes in E. coli protein antibodies were observed. It is concluded that r-hGH is an efficient and safe treatment for children with growth hormone deficiency.

Injury and repair of smaller muscular and elastic arteries. Immunohistochemical demonstration of fibronectin and fibrinogen/fibrin and their degradation products in rabbit femoral and common carotid arteries following a dilatation injury

Indirect immunoperoxidase staining for fibrinogen/fibrin and fibronectin was performed on normal and healing arterial tissue of muscular and smaller elastic arteries. Fibronectin was observed in the wall of the normal arteries, whereas fibrinogen/fibrin could not be demonstrated. Fibronectin was observed in the intima as well as the media deposited in a similar fashion in the femoral and carotid artery during repair. Apart from the early occurrence of fibrin/fibrinogen in the media of both arteries the distribution of fibrinogen/fibrin and degradation products differed. In the femoral artery a progressively weakening positive reaction for fibrinogen/fibrin and degradation products towards the lumen was observed in the intima and the media 7 and 14 days after the lesion. By 28 days the reaction in the media was negative. No thrombus formation was observed. In contrast, all the specimens examined from the common carotid arteries were obliterated by luminal thrombi 28 days after the lesion. The thrombus as well as the damaged intimal thickening and the compressed media were loaded with fibrinogen/fibrin and degradation products. The deposition of fibronectin, fibrinogen, and degradation products in the carotid artery was similar to that previously reported in experimental aortic arteriosclerosis in rabbits as well as in giant cell arteritis.

Glycogen synthase from human and bovine polymorphonuclear leukocyte. Immunochemical characterization and comparison to glycogen synthase from rat and rabbit muscle and liver cells

Glycogen synthase from human and bovine polymorphonuclear leukocytes was purified to homogeneity. Rabbit antisera were raised against the two glycogen synthases and used for immunochemical analysis. Western blotting analysis showed that the subunit of glycogen synthase in crude homogenates of human and bovine leukocytes in both cases has an Mr of 85,000. The existence of a cross-reactivity between the two enzymes and the corresponding antisera demonstrates immunological similarities between bovine and human leukocyte glycogen synthase. In addition, both antisera recognize glycogen synthase in crude cellular extracts from rabbit and rat liver and from skeletal muscle. Leukocyte glycogen synthase, therefore, cannot be classified as either muscle (M-type) or liver (L-type) glycogen synthase and our results do not support the proposed immunochemical distinction between M- and L-type glycogen synthase.

Incidence of bilateral testicular germ cell cancer in Denmark, 1960-84: preliminary findings

The incidence of a second primary testicular germ cell cancer in the contralateral testicle among 2338 men with a first primary testicular germ cell cancer diagnosed in the years 1960-79 in Denmark was established in this preliminary report. The material represents 83% of the total cohort followed until 31 December 1984. The relative risk for a patient with testicular cancer to get yet another testicular cancer was studied, taking into account the histology of the first primary testicular germ cell cancer. Based on fifty-eight nonsimultaneous contralateral testicular cancer cases and 19,995 'person-years at risk', the overall relative risk of invasive germ cell cancer in the contralateral testicle following a first germ cell testicular cancer was found to be 23.3 (95% confidence interval: 18-30). Among men with nonseminoma the risk was higher (relative risk = 27.5) than among men with seminomas (relative risk = 20.1). Overall, sixty-two (2.7%) patients developed a second cancer. In four of these patients bilateral tumours occurred simultaneously.

Injury and repair of smaller muscular and elastic arteries. A light microscopical study on the different healing patterns of rabbit femoral and carotid arteries following dilatation injuries by a balloon catheter

26 rabbits of the Danish country strain were subjected to mechanical dilatation injury of the left femoral and carotid arteries with Fogarty's embolectomy catheters F2 and F3 respectively. The rabbits were killed 2, 7, 14 and 28 days after the dilatation injury and the arteries examined histologically. Initially both of the arteries exhibited necrosis of the media and infiltration of the vessel wall with neutrophils and mononuclear cells. From day 7, intimal thickening was observed in both types of arteries, progressing in thickness during the later stages. However, thrombosis occurred in the majority of the carotid arteries, whereas this was only infrequently seen in the femoral arteries. In all of the dilated arteries, the elastic laminas were stretched or fragmented and never regained their normal appearance. In the carotid artery, giant cells accumulated around the fragmented elastin and calcified areas, located primarily at the intima-medial border. These changes were never observed in the femoral artery. At the twenty-eight days stage, proliferation of the smooth muscle cells more or less led to restitution of the media in the femoral artery, whereas the carotid artery showed medial restitution only to a lesser extent. The similarities between the injured carotid artery and human temporal arteritis, and the utility of the model as an animal model for the study of temporal arteritis are underlined.

Purification and properties of glycogen synthase I from bovine polymorphonuclear leucocytes

Glycogen synthase I was purified from bovine polymorphonuclear leucocytes (PMNs) by a procedure involving concanavalin A-Sepharose affinity chromatography. The purified glycogen-bound glycogen synthase I had a specific activity of 9.83 U/mg protein and the glycogen free enzyme 21 U/mg protein. Molecular ratio of the native enzyme and the subunit were 340 K and 85 K respectively. After phosphorylation by the catalytic subunit of cAMP-dependent protein kinase the phosphorylated sites were studied using high-performance liquid chromatography (HPLC) of the tryptic 32P-peptides. The enzyme was phosphorylated at three different sites with retention times identical to site 1a, site 1b, and site 2 from rabbit skeletal muscle glycogen synthase.

Large-scale isolation of polymorphonuclear leucocytes from bovine blood

A method for the isolation of an enriched population (greater than 96%) of bovine polymorphonuclear leucocytes (PMNs) from 70 liters of blood was developed using a two-step procedure involving separation of the blood, in a packed red blood cell fraction containing the PMNs and a plasma fraction, by continuous flow blood separation. Hypotonic lysis of erythrocytes was then followed by centrifugation at 200 g sedimenting the PMNs. The yield was 93 +/- 30 g, the recovery was 62 +/- 20%, viability was greater than 95%. Since bovine blood can be obtained in unlimited amounts, the procedure described here can be applied to obtain large amounts of bovine PMNs for incubation studies and large-scale purification of intracellular enzymes suitable for biochemical characterization.

Creatine phosphokinase MB and lactate dehydrogenase isoenzyme 1 in polymyositis

Serious cardiac abnormalities and asymptomatic hyperkinetic heart function are frequently seen in patients with polymyositis/dermatomyositis (PM). The cardiac manifestations may be secondary to myocardial inflammation, replacement fibrosis, or alterations in the peripheral circulation. The significance of determinations of cardiospecific isoenzymes in the evaluation of myocardial manifestations in PM has not yet been established. We report on 2 patients with firm evidence of severe myocardial involvement. Nevertheless, the serum levels of creatine phosphokinase MB (CPK MB) and lactated dehydrogenase isoenzyme 1 (LDH1) were found normal. This finding casts doubt on the reliability of cardiospecific isoenzymes for the identification of inflammatory myocardial involvement in patients with PM.