Poor Prestroke Glycemic Control Increases the Rate of Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy

(1) Background: Diabetes is a well-established risk factor for acute ischemic stroke (AIS). This study evaluated the impact of prestroke glycemic control in diabetic patients on their 3-month clinical outcome after mechanical thrombectomy (MT). (2) Methods: AIS patients with a premorbid modified Rankin scale (mRS) score of 0-2 who were admitted within 6 h after stroke onset and treated with MT between January 2020 and August 2023 were retrospectively analyzed. The study evaluated the effect of prestroke glycemic control on the stroke severity, reperfusion rate, symptomatic intracranial hemorrhage (sICH) and favorable clinical outcome (modified Rankin scale score 0-2) at 3 months after endovascular treatment. (3) Results: A total of 364 patients were analyzed, with 275 cases of non-diabetes (ND), 66 of well-controlled diabetes (WCD) and 23 of poorly controlled diabetes (PCD). There was no significant difference in the baseline neurological deficit expressed according to the National Institutes of Health Stroke Scale among the three groups. The time from stroke onset to groin puncture was similar in the ND, WCD and PCD groups (median 215 min, 194.5 min and 222.5 min, respectively). There was no significant difference in the favorable 3-month clinical outcomes among these three groups (35.2% of ND patients, 42.4% of WCD patients and 39.1% of PCD patients) or full recovery (12.4% of ND patients, 11.0% of WCD patients and 17.4% of PCD patients). The rate of sICH was significantly higher in the PCD group as compared to the ND and WDP groups (21.7% of PCD patients versus 7.6% of ND patients, p = 0.038, and 6.0% of WCD patients, p = 0.046), but the 3-month mortality did not differ between the three groups (21.8% of ND group, 19.7% of WCD group and 26.1% of PCD group). (4) Conclusions: This study shows that poor prestroke glycemic control in AIS diabetic patients does not change the chance of a good clinical functional outcome after endovascular treatment. However, the increased risk of hemorrhagic complications in this group of patients should be considered.

Preoperative glycated hemoglobin concentration and early postoperative infections in patients undergoing spinal surgery: A systematic review

Early postoperative infections can affect a significant number of spinal surgery patients. Many studies reported on the features that may associate with elevated risk of infectious complications in this group. Data on the impact of glucose metabolism disorders in this area are well known. At the same time information on the correlation of preoperative HbA1c level and postoperative infections in spinal surgery are still scarce. Furthermore there are no strict recommendations regarding routine HbA1c testing prior to elective surgery. In present SR we aimed to report available clinical evidence on association between preoperative HbA1c and early postoperative infections. We used PubMed and EMBASE database and a set of specific key words (spine surgery AND infections AND HbA1c) to identify eligible studies. The study was registered in PROSPERO database and reported according to PRISMA recommendations. 16 studies were selected for further assessment. Predominance of data indicated a significant correlation between preoperative HbA1c concentration and elevated risk of postoperative infections, as well as higher rate of non - infective complications and worse patients future outcome. Adequately designed future studies on purposely dimensioned sample size are needed to confirm the role of preoperative HbA1c testing in preoperative management of spinal surgery patients.

Direct admission vs. secondary transfer for mechanical thrombectomy: long-term clinical outcomes from a single Polish Comprehensive Stroke Centre

INTRODUCTION

We aimed to compare 3-month clinical outcomes after mechanical thrombectomy (MT) in patients transferred directly to a comprehensive stroke centre ('mothership', MS) to the outcomes of patients transferred secondarily from primary stroke centres ('drip-and-ship', DAS) in Lubelskie province, the third largest province in Poland.

MATERIALS AND METHODS

In a prospective stroke registry, all patients with large vessel occlusion in anterior circulation admitted within six hours of onset and treated with MT between 2017 and 2020 were retrospectively analysed.

RESULTS

A total of 400 patients was evaluated: 267 treated with the MS approach and 133 with the DAS approach. Time from stroke onset to groin puncture was shorter in the MS group. There was a significant difference in 3-month excellent clinical outcomes (mRS 0-1) between these two groups (32.9% of MS patients vs. 22.5% of DAS patients, p < 0.05), but there was no difference if the 3-month endpoint was expressed as mRS ≤ 2 (42.3% of MS vs. 34.5% of DAS patients, p = 0.13). The rate of symptomatic intracranial haemorrhage and mortality was comparable in both groups.

CONCLUSIONS

Our study shows that direct admission to a comprehensive stroke centre resulted in more patients achieving excellent treatment outcomes (mRS 0-1). At the same time, the superiority of the MT model over the DAS model in obtaining mRS 0-2 was not unequivocally demonstrated. Further studies are needed to determine the best stroke model for patients potentially eligible for MT.

Stroke patients from rural areas have lower chances for long-term good clinical outcome after mechanical thrombectomy

BACKGROUND

This study evaluated 3-months clinical outcome after mechanical thrombectomy (MT) in stroke patients transferred to a comprehensive stroke center (CSC) from a rural and urban areas in a Lubelskie province, the third largest province in Poland.

MATERIALS AND METHODS

Acute stroke patients with a premorbid modified Rankin scale (mRS) score 0-2 who were admitted within 6 h after stroke onset and treated with MT between 2016 and 2020 were retrospectively analyzed. Patients from rural and urban areas transported directly to CSC were compared regarding the onset-to-groin time, reperfusion rate, symptomatic intracranial hemorrhage (sICH) and favourable clinical outcome (modified Rankin Scale score 0-2) 3-months after MT.

RESULTS

A total of 398 patients were analyzed: 179 from rural areas (RA) and 219 from urban areas (UA). There was no significant difference in baseline neurological deficit expressed in The National Institutes of Health Stroke Scale (median 18.4 for RA patients versus 18.1 for UA patients, p = 0.70). Time from stroke onset to groin puncture was significantly shorter in the UA patients (median 197.3 min versus 219.6 min, p = 0.004). There was a significant difference in 3 months favourable clinical outcome between these two groups (31.3% of RA patients versus 42.5% of UA patients, p = 0.021) and full recovery rates (5.6% of RA patients versus 15.0% of UA patients, p = 0.002). The rate of sICH and 3-months mortality was similar in both groups (7.3% of RA patients versus 8.7% of UA patients, p = 0.61% and 21.8% of RA group vs. 22.4% of UA group, p = 0.88, respectively).

CONCLUSION

Stroke patients from RA undergoing thrombectomy had worse functional outcome compared to UA patients. Since the benefit of MT is time dependent, urban-rural differences in stroke outcome probably result from the longer time from stroke onset to reperfusion treatment in RA patients.

Entrapping of the spin label tempocholine into human erythrocytes by resealing after hyposmolar stress. Comparison with haemolysis. The effects of some membrane-active substances

Human erythrocytes were subjected to a sudden hyposmolar stress by suspension in solutions of varying salt concentrations in the presence of the spin label tempocholine. The enlarged pores in the erythrocyte membranes produced by the influx of water, followed by stretching, allowed the passage of the spin label, so that a certain amount of tempocholine was entrapped when the erythrocytes spontaneously resealed with closing of the pores. The excess of spin label in the external solution was then reduced to a diamagnetic species by the addition of ascorbic acid. The positively charged tempocholine and the ascorbic acid did not penetrate properly resealed erythrocytes, so that the electron spin resonance (ESR) signal from the entrapped spin label constituted a measure of the effective resealing of the pores and rifts in the membrane subsequent to hyposmolar stress. Some drug substances were found to influence the entrapping curves obtained when the amount of entrapped spin label was plotted against the osmolarity. Chlorpromazine, trifluoperazine, nicardipine, amperozide and haloperidol gave rise to a dose-dependent decrease of the entrapping of tempocholine, especially at low osmolarities. The exclusion of Ca2+ and Mg2+ ions from the solutions increased the action of chlorpromazine. The protective action against haemolysis brought about by a number of membrane-active substances at low concentrations [2] had its counterpart in the entrapping curve observed with chlorpromazine at 0.1 mM. It is suggested that the substances in this series exerted their action on the resealing process by interaction with the calmodulin system.

Characterization of acid and alkaline phosphatase activity in preparations of tubulin and microtubule-associated proteins

Acid and alkaline phosphatase activity, determined by the hydrolysis of p-nitrophenyl phosphate, was found in preparations of microtubules purified from bovine brain by temperature-dependent assembly-disassembly and ion-exchange chromatography. Phosphocellulose-purified tubulin contained an associated acid phosphatase activity, stimulated by Mg2+ and by Zn2+. Alkaline phosphatase activity with a pH optimum of 10.4 was measured in a fraction of microtubule-associated proteins (MAPs). Kinetics and the effects of sodium fluoride, sodium tartrate, sulfhydryl-blocking agents, EDTA and Zn2+ are reported.

The ATPase activity in brain microtubule preparations is membrane-associated

Microtubule protein prepared from bovine brain by a temperature-dependent assembly-disassembly procedure contained Mg2+- or CA2+-stimulated ATPase activity. However, activity decreased with successive cycles of assembly-disassembly such tht 15% of the Mg2+-stimulated and 31% of the Ca2+-stimulated activity of the second-cycle material remained after seven cycles. Microtubule preparations purified by three cycles of assembly-disassembly contained many membrane fragments and vesicles which were absent in microtubule preparations cycled eight times. Histochemistry and electron microscopy revealed that much of the activity is associated with the vesicles. Vesicles with an accumulation of led phosphate deposits (indication of ATPase activity) were observed in high-speed pellets (150,000 g, 60 min) of microtubule-associated proteins. Most of the activity in the microtubule-associated protein preparations, but only a fraction of the total protein is pelleted. 53-78% of the ATPase activity, but only 6% of the total protein, is recovered in a microtubule-associated protein fraction eluted from phosphocellulose with 0.17 M NaCl. Polypeptides resolved on SDS polyacrylamide gradient gels have estimated molecular weights of 30,000-76,000. Electron micrographs of this material revealed short filaments, vesicles, and small ring-like structures. None of the inhibitors of possible contaminating ATPases affected the ATPase activity.

Ca2+- or Mg2+-dependent enzymatic ATP hydrolysis associated with the microsomal fraction of frog sciatic nerves

The microsomal fraction of frog sciatic nerves was found to contain Ca2+- or Mg2+-dependent hydrolytic activity toward different nucleoside di- and triphosphates. In the presence of Ca2+ substrate specificity was in the order CTP > UTP > GTP > ATP. When Mg2+ was used, the triphosphates were approximately equally good substrates. ATP hydrolytic activity was very similar with Ca2+ or Mg2+ as the cofactor, whereas Ca2+ was the more potent activator of hydrolysis of the other triphosphates tested. The preparation showed some activity toward the nucleoside diphosphates but none toward the monophosphates or p-nitrophenylphosphate. The enzymic properties of ATP hydrolysis were more closely studied. The hydrolysis was optimal at 18--24 degrees C in the presence of 1 mM-Ca2+ or 1 mM-Mg2+. Ca2+- and Mg2+-ATP hydrolysis displayed pH maxima around 8.0--8.5 and 7.4--8.0, respectively. Vmax values for Ca2+- and Mg2+-ATP hydrolysis similar: approx. 12 mumol Pi per h per mg protein with a Km value of approx. 0.05 mM. The ATP hydrolysis activity was inhibited by NaF but unaffected by ouabain, vanadate, cytochalasin B, and various drugs known to influence ATPase activity of mitochondria. Zn2+ stimulated the ATP hydrolysis activity at low concentrations (10(-6)-10(-5) M) and inhibited it at higher concentrations. The possibility that these observations account for stimulation and inhibition of axonal transport in frog sciatic nerves exposed to similar concentrations of Zn2+ is discussed.

The association of carbohydrate with tubulin and in vitro assembled microtubules from bovine brain

Phosphocellulose-purified tubulin (PC tubulin) was analyzed for neutral and amino sugar content, which was found to be 8.3 +/- 0.11 and 0.8 +/- 0.02 mol/mol dimer, respectively. A histochemical-electron-microscopic investigation was undertaken to attempt to localize carbohydrate associated with polymerized microtubules (MT). Outer diameters of MT assembled in vitro from bovine brain MT protein (tubulin and microtubule associated proteins) were found to increase upon treatment with ruthenium red, Alcian blue, and lanthanum hydroxide, which have been reported to possess specificity for complex carbohydrates. Concanavalin A-reactive sites were detected on the surface and in the lumen of MT assembled from MT protein and from PC tubulin.