Red-cell GSH regeneration and glutathione reductase activity in G6PD variants in the Ferrara area

Summary. Red-cell studies were carried out on three groups of G6PD-deficient subjects with different G6PD variants from the Ferrara area of Northern Italy. Red-cell GSH and activities of G6PD, glutathione reductase (GR), glutathione peroxidase (GPx) and superoxide dismutase (SOD) were measured. A method was developed to measure red-cell GSH regeneration after oxidation of endogenous GSH in whole blood by diamide and only this clearly distinguished the variants from each other and from normal. Regeneration by 1 h was lowest in the Mediterranean variant, 0–10.2% in contrast to 93–98% in normal. A predisposition to a haemolytic crisis after ingestion of fava beans was not clearcut, but subjects appeared to be at risk if GSH regeneration at 1 h was less than 30% of the endogenous level, and red-cell FAD⁺ was very high indicated by high in vitro GR activity and inhibition by added FAD⁺.
It is suggested that the most informative tests in G6PD deficiency are measurements of GSH regeneration in intact red cells plus GR activity and/or red-cell flavin compounds.     

Marrow transplantation with or without donor buffy coat cells for 65 transfused aplastic anemia patients

Sixty-five multiply transfused patients with severe aplastic anemia were given cyclophosphamide followed by grafts anemia were given cyclophosphamide followed by grafts from HLA-identical siblings. The effect of the administration of viable donor buffy coat cells following the marrow inoculum was evaluated with regard to graft rejection and survival. Results in 43 patients so treated are presented along with those in 22 concurrent patients given marrow alone. Most patients given buffy coat had positive in vitro tests of sensitization indicating a high risk for graft rejection, while all but one of the patients given marrow alone had negative tests. Thirty of the 43 (70%) patients given marrow and buffy coat are alive between 10 and 61 mo (median 36) after grafting; 4 died after graft rejection and 6 with acute or chronic graft-versus-host disease (GVHD). Eleven of the 22 (50%) patients given marrow alone are alive between 29 and 65 mo (median 52); 7 died after graft rejection and 3 with GVHD. The addition of buffy coat cell infusions to the marrow inoculum reduced the risk of rejection and increased survival in the currently reported transfused patients when compared to patients grafted before 1976. However, there was an increased risk of chronic GVHD. Recipients of marrow from female donors survived slightly better (73%) than recipients of male marrow (58%).     

Phase I trial of interleukin-2 after unmodified HLA-matched sibling bone marrow transplantation for children with acute leukemia

Allogeneic bone marrow transplantation (BMT) for advanced acute leukemia is associated with a high risk of relapse. It is postulated that interleukin-2 (IL-2) administered after BMT might induce or amplify a graft-versus-leukemia effect and thereby reduce the relapse rate. To identify an IL-2 regimen for testing this hypothesis, a phase I trial of IL-2 (Roche) was performed in children in complete remission (CR) without active graft-versus-host disease (GVHD) off immunosuppressive agents after unmodified allogeneic matched-sibling BMT for acute leukemia beyond first remission. Beginning a median of 68 days after BMT, 17 patients received escalating doses of induction IL-2 (0.9, 3.0, or 6.0 x 10(6) IU/m2/d representing levels I, II, and III) for 5 days by continuous intravenous infusion (CIV). After 6 days of rest, they received maintenance IL-2 (0.9 x 10(6) IU/m2/d) for 10 days by CIV infusion. Levels I and II were well-tolerated, but, of 6 patients at level III, 1 developed pulmonary infiltrates, 1 developed hypotension (both resolved), and 1 died of bacterial sepsis and acute respiratory distress syndrome. Grade II acute GVHD developed in 1 patient at level I and 1 at level III. The maximum tolerated dose of induction IL-2 was level II. IL-2 induced lymphocytosis, with an increase in CD56+ and CD8+ cells. Ten patients remain in CR at 5+ to 67+ months. Thus, a regimen of IL-2 has been identified that did not induce a high incidence of acute GVHD when administered to children after unmodified allogeneic BMT. Its clinical activity will be assessed in a phase II trial.     

Normal synthesis and expression of endothelial IIb/IIIa in Glanzmann's thrombasthenia

Glanzmann's thrombasthenia is a bleeding disorder, inherited in an autosomal recessive way and characterized by an absence or deficiency of the platelet glycoprotein (GP) IIb/IIIa complex. Recently, we and others demonstrated that cultured human umbilical vein endothelial cells synthesized a membrane protein complex similar to the platelet GP IIb/IIIa complex. In this article, we demonstrate that endothelial cells isolated from the umbilical vein of a newborn with Glanzmann's thrombasthenia, as compared with normal endothelial cells, show no difference in their ability to synthesize and express this GP IIb/IIIa complex. Our results indicate that Glanzmann's thrombasthenia is not accompanied by an "endotheliopathy."     

A humanised tissue‐engineered bone model allows species‐specific breast cancer‐related bone metastasis in vivo

Bone metastases frequently occur in the advanced stages of breast cancer. At this stage, the disease is deemed incurable. To date, the mechanisms of breast cancer‐related metastasis to bone are poorly understood. This may be attributed to the lack of appropriate animal models to investigate the complex cancer cell–bone interactions. In this study, two established tissue‐engineered bone constructs (TEBCs) were applied to a breast cancer‐related metastasis model. A cylindrical medical‐grade polycaprolactone‐tricalcium phosphate scaffold produced by fused deposition modelling (scaffold 1) was compared with a tubular calcium phosphate‐coated polycaprolactone scaffold fabricated by solution electrospinning (scaffold 2) for their potential to generate ectopic humanised bone in NOD/SCID mice. While scaffold 1 was found not suitable to generate a sufficient amount of ectopic bone tissue due to poor ectopic integration, scaffold 2 showed excellent integration into the host tissue, leading to bone formation. To mimic breast cancer cell colonisation to the bone, MDA‐MB‐231, SUM1315, and MDA‐MB‐231BO breast cancer cells were cultured in polyethylene glycol‐based hydrogels and implanted adjacent to the TEBCs. Histological analysis indicated that the breast cancer cells induced an osteoclastic reaction in the TEBCs, demonstrating analogies to breast cancer‐related bone metastasis seen in patients.     

CaMKIIδ and cardiomyocyte Ca2+ signalling new perspectives on splice variant targeting

Control of cardiomyocyte cytosolic Ca²⁺ levels is crucial in determining inotropic status and ischemia/reperfusion stress response. Responsive to fluctuations in cellular Ca²⁺, Ca²⁺/calmodulin‐dependent protein kinase II (CaMKII) is a serine/threonine kinase integral to the processes regulating cardiomyocyte Ca²⁺ channels/transporters. CaMKII is primarily expressed either in the δ_B or δ_C splice variant forms, which may mediate differential influences on cardiomyocyte function and pathological response mechanisms. Increases in myocyte Ca²⁺ levels promote the binding of a Ca²⁺/calmodulin complex to CaMKII, to activate the kinase. Activity is also maintained through a series of post‐translational modifications within a critical region of the regulatory domain of the protein. Recent data indicate that the post‐translational modification status of CaMKIIδ_B/δ_C variants may have an important influence on reperfusion outcomes. This study provided the first evidence that the specific type of CaMKII post‐translational modification has a role in determining target selectivity of downstream Ca²⁺ transporters. The study was also able to demonstrate that the phosphorylated form of CaMKII closely co‐localizes with CaMKIIδ_B in the nuclear/myofilament fraction, contrasting with a co‐enrichment of oxidized CaMKII in the membrane fraction with CaMKIIδ_C. It has also been possible to conclude that a hyper‐phosphorylation of CaMKII (Thr287) in reperfused hearts represents a hyper‐activation of the CaMKIIδ_B, which exerts anti‐arrhythmic actions through an enhanced capacity to selectively increase sarcoplasmic reticulum Ca²⁺ uptake and maintain cytosolic Ca²⁺ levels. This suggests that suppression of global CaMKIIδ may not be an efficacious approach to developing optimal pharmacological interventions for the vulnerable heart.     

von Willebrand disease "Vicenza" with larger-than-normal (supranormal) von Willebrand factor multimers

When normal volunteers or patients with type I von Willebrand disease (VWD) are given desmopressin (DDAVP), a set of larger-than-normal (supranormal) von Willebrand factor (VWF) multimers, similar to those present in VWF-containing cells such as platelets megakaryocytes and endothelial cells, appear transiently in postinfusion plasma. In two kindreds with mild lifelong bleeding symptoms transmitted as an autosomal dominant trait, all ten symptomatic members (but none of the five asymptomatic members) had a supranormal multimeric structure for plasma VWF, apparently identical to that seen for postdesmopressin normal plasma. Plasma factor VIII coagulant activity (VIII:C), VWF antigen (VWF:Ag), ristocetin-induced platelet agglutination, and ristocetin cofactor (RiCof) activity were low. Platelet VWF:Ag and RiCof levels (tested for three patients only) were normal. Bleeding times were normal or slightly prolonged. The patients' platelet multimeric structure was the same as that for normal platelets. After desmopressin infusion the plasma VWF multimeric structure remained supranormal as for preinfusion plasma, with VIII:C VWF:Ag and RiCof increasing markedly over baseline values and disappearing at a normal rate. Examination of the VWF subunit composition from three of these patients indicated that proteolytic processing of their VWF did not differ from normal. This study describes the first variant of VWD with a supranormal multimeric structure.     

Risk factors for calcification of the vertebrobasilar arteries in cardiovascular patients referred for a head CT,the SMART study

Background and purposeVertebrobasilar artery calcification (VBAC) has been associated with increased stroke occurrence. Little is known on VBAC risk factors, especially for patients with cardiovascular disease. We aimed to assess risk factors associated with VBAC in a cohort of cardiovascular patients referred for a head computed tomography (CT) scan.Materials and methodsAll patients who underwent a clinically indicated, unenhanced, thin slice head CT 6 months before or after inclusion in the SMART study were included. CTs were assessed for presence of VBAC (dichotomously). Relative risks of the associations of age, sex, diabetes mellitus (DM), obesity, body mass index, estimated glomerular filtration rate, hypertension, hyperlipidemia, use of lipid lowering medication, smoking status, high sensitivity C-reactive protein, ankle-brachial index (ABI; ≤ 0.90, ≥ 1.30, continuous), internal carotid artery stenosis ≥ 70%, and carotid intima-media thickness (IMT) with VBAC were estimated using Poisson regression analysis with robust standard errors, adjusted for age and sex.ResultsOf the 471 patients included (57% male, median age 58 [interquartile range 47–63]), 117 (24.8%) showed VBAC. Presence of VBAC was associated with older age (RR per 10 years = 1.70 [95%CI 1.46–1.99]), DM (RR = 1.45 [95%CI 1.03–2.06]), obesity (RR = 1.53 [95%CI 1.10–2.12]), ABI ≤ 0.90 (RR = 1.57 [95%CI 1.02–2.41]), and an increased carotid IMT (RR = 2.60 per mm [95%CI 1.20–5.62]). Other measurements were not associated with VBAC.ConclusionsWe identified several markers associated with VBAC in patients with cardiovascular disease referred for a head CT. Future investigation into the relationship between VBAC and stroke is warranted to determine the potential of VBAC in stroke prevention.     

Long-COVID postural tachycardia syndrome: an American Autonomic Society statement

COVID-19 is a global pandemic that has had a devastating effect on the health and economy of much of human civilization. While the acute impacts of COVID-19 were the initial focus of concern, it is becoming clear that in the wake of COVID-19, many patients are developing chronic symptoms that have been called Long-COVID. Some of the symptoms and signs include those of postural tachycardia syndrome (POTS). Understanding and managing long-COVID POTS will require a significant infusion of health care resources and a significant additional research investment. In this document from the American Autonomic Society, we outline the scope of the problem, and the resources and research needed to properly address the impact of Long-COVID POTS.

     

Return to sporting activity after Birmingham hip resurfacing arthroplasty: Mid term results

Background:

Hip resurfacing arthroplasty (HRA) is primarily indicated for young, active patients with disabling coxarthrosis who wish to remain active and return to sports after surgery. Relatively few prospective studies have assessed return to sporting activity and impact of gender and age on this.

Materials and Methods:

Seventy-nine consecutive patients treated with HRA were included. Patients were reviewed clinically and radiologically. Function was assessed using the modified University of California Los Angeles (UCLA) activity score. The Oxford, Harris and WOMAC hip scores were calculated.

Results:

Average age at the time of surgery was 54.9 years (range 34.5–73.6 years). Average preoperative and postoperative UCLA scores were 4 and 7.6 respectively. Patients were involved in 2 (0–4) sporting activities preoperatively and 2 (0–5) postoperatively. Preoperative and postoperative Oxford Hip Scores, Harris Hip Score and WOMAC scores were 40, 46 and 51 and 16, 94 and 3 respectively (P < 0.0001). Patients returned to sports at an average of 3 months postoperatively.

Conclusion:

Patients were able to return to sports by 3 months and perform the same number of activities at preoperative intensity. Activity levels are maintained up to the medium term with few complications.