Antileukinate,a hexapeptide inhibitor of CXC-chemokine receptor,suppresses bleomycin-induced acute lung injury in mice

Abstract A hexapeptide, Ac-RRWWCR-NH₂ (Antileukinate), has been reported to be a potent inhibitor of CXC-chemokine receptor. However, the in vivo anti-inflammatory activity of this agent has not been tested except in a rabbit skin edema model. This study was undertaken to investigate the effect of subcutaneously administered Antileukinate on experimental bleomycin-induced acute lung injury in mice, in which CXC-chemokines have been reported to be involved. Lung injury was assessed on the basis of histopathology, the number of total cells, the percentage of neutrophils, and protein concentration in the bronchoalveolar lavage (BAL) fluid, and the wet lung weight at 7 days after intratracheal instillation of bleomycin. Histopathological studies revealed that treatment with Antileukinate markedly suppressed inflammatory cell infiltration and interstitial lung edema. The neutrophil counts in the BAL fluid were significantly decreased in the Antileukinate-treated group. The suppression of pulmonary edema was further confirmed by the reduction of wet lung weight and total protein concentration in the BAL fluid. These findings suggest that Antileukinate is able to inhibit acute lung injury by suppressing neutrophil mobilization induced by CXC-chemokines.     

A randomized,double-blind,placebo-controlled trial of infliximab in refractory polymyositis and dermatomyositis

ObjectiveTo investigate in a pilot study the safety and efficacy of infliximab in patients with refractory dermatomyositis (DM) and polymyositis (PM).MethodsA randomized, double-blind, placebo-controlled trial including subjects with active DM or PM. Participants had stable doses of immunosuppressive medication and prednisone (≤0.5 mg/kg/day), and exhibited clinical signs of muscle weakness for at least 4 weeks prior to study entry. Participants received infusions of either placebo or infliximab 5 mg/kg at 0, 2, 6, and 14 weeks in blinded manner. The primary outcome was a ≥15% manual muscle strength (MMT) improvement at week 16 compared to week 0. The secondary outcome measures were improvement defined by the International Myositis Assessment and Clinical Studies Group (IMACS) criteria. At week 16, responders in each arm had the option of either continuing the same treatment or changing to the non-responder treatment for that study arm. Non-responders in the 5 mg/kg infliximab arm were increased to infliximab 7.5 mg/kg for weeks 22, 30, and 38. Non-responders in the placebo arm at week 16 received infliximab 5 mg/kg at weeks 16, 18, 22, 30, and 38. Outcomes were reassessed at week 40.ResultsTwelve subjects completed the study to week 16. Six of the 12 subjects received infliximab treatment at the dose of 5 mg/kg with only one subject meeting the responder criteria at that dose. Of the remaining five subjects on infliximab, three crossed over to the infliximab 7.5 mg/kg dose. One of those three subjects responded. All six patients in the placebo arm crossed over to the 5 mg/kg dosing regimen after week 16, and two of those responded to infliximab.ConclusionsInfliximab therapy for patients with refractory PM and DM was well tolerated and may benefit a subset of patients.     

Gastric inflammation, metaplasia, and tumor development in gastrin-deficient mice

BACKGROUND & AIMS: Gastrin deficiency and proton pump inhibitor treatment cause achlorhydria, which predisposes to disease. To elucidate the underlying molecular biology, we examined the changes in gastric gene expression in both types of achlorhydria. We also explored the associated changes in the gastric microflora and the long-term consequences of gastrin-deficient achlorhydria. METHODS: Expression profiles were generated from gastric RNA from wild-type mice, gastrin knockout (KO) mice, gastrin KO mice after 1 week of gastrin infusion, and wild-type mice treated for 1 month with a proton pump inhibitor. The results were confirmed using real-time polymerase chain reaction and immunohistochemistry. Selective media were used to characterize the gastric microflora. RESULTS: The number of gastric bacteria was increased in both gastrin KO and PPI-treated mice. The expression profiles revealed activation of immune defense genes, interferon-regulated response genes, and intestinal metaplasia of the gastric mucosa. In young gastrin-deficient mice, gastrin infusions reversed the changes. Over time, the changes accumulated, became irreversible, and progressed into metaplasia and polyp development. Finally, the study showed that gastrin regulated the expression of genes encoding extracellular matrix proteins. CONCLUSIONS: Independently of gastrin, achlorhydria is associated with gastric bacterial overgrowth and intestinal gene expression patterns and is associated with predisposition to disease. Gastrin is therefore essential for prevention of gastric disease, mainly through control of acid secretion but to a lesser extent also through control of gastric gene expression. The gastrin-deficient mouse serves as a useful new model for gastric metaplasia and neoplasia.     

Acquired factor VIII inhibitor treated with cyclophosphamide, vincristine, and prednisone

Life-threatening bleeding can occur in non-hemophiliacs with factor VIII inhibitor and is difficult to control. Various methods have been used to suppress the inhibitor. Since 1993 we treated 6 non-hemophilic patients with factor VIII inhibitor with cyclophosphamide, vincristine, and prednisone (CVP) every 3-4 weeks. Five had complete response with disappearance of factor VIII inhibitor and normalization of factor VIII after 1 to 7 cycles of CVP. One patient did not respond after 4 cycles of CVP; mitoxantrone was added to additional two cycles of CVP, and the inhibitor disappeared.     

Hereditary angioedema: new findings concerning symptoms, affected organs, and course

Purpose

Hereditary angioedema (HAE) due to C1 inhibitor deficiency is clinically characterized by relapsing skin swellings, abdominal pain attacks, and life-threatening upper airway obstruction. Our aim was to examine a temporal and spatial pattern of the edema episodes by evaluating the long-term course of hereditary angioedema in order to establish a specific swelling pattern.

Subjects and methods

Data were generated from 221 patients with C1 inhibitor deficiency by asking them about symptoms they experienced during their edema episodes. Documentation was accomplished through the use of standardized questionnaires.

Results

A total of 131 110 edema episodes were observed. Clinical symptoms started at a mean age of 11.2 (SD 7.7) years. During the following cumulative 5736 years, only 370 (6.5%) symptom-free years occurred. Skin swellings, including extremity, facial, genital, and trunk swellings, and abdominal attacks occurred in 97.4% of all edema episodes of the disease. The other episodes were laryngeal edema (0.9%); edema of the soft palate (0.6%); tongue swellings (0.3%); headache episodes (0.7%); episodes affecting urinary bladder (0.3%), chest (0.2%), muscles (0.4%), joints (0.1%), kidneys (0.1%), and esophagus (0.05%), and were partly combined with other edema episodes. The per-patient analysis and the per-episode analysis revealed markedly discrepant results. On average, women had a more severe course of the disease than men. Patients with early onset of clinical symptoms were affected more severely than those with late onset.

Conclusion

The described swelling pattern is specific for HAE and allows a tentative diagnosis based on clinical symptoms and the course of the disease.     

Pathophysiology, diagnosis, and treatment of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Activating mutations of KIT or the platelet-derived growth factor receptor alpha gene (PDGFRA) have been identified in the vast majority of GISTs. The respective oncoproteins exhibit constitutive tyrosine kinase activity and promote cell growth. KIT and PDGFRA mutations are rarely found in GISTs in patients with neurofibromatosis type 1 (NF1) suggesting that the pathogenesis of GIST in NF1 patients is different from that in non-NF1 patients. Endoscopic diagnosis of GIST is usually difficult. Endoscopic ultrasonography (EUS)-guided fine-needle aspiration biopsy (EUS-FNAB) is a useful method for the diagnosis of GIST and for the detection of KIT or PDGFRA mutations. Imatinib mesylate, a tyrosine kinase inhibitor known to inhibit the activities of BCR-ABL, KIT, and PDGFR, is currently being used for the treatment of both chronic myeloid leukemia and metastatic GIST. The clinical response to imatinib therapy correlates with the types of mutations of KIT and PDGFRA, and the determination of KIT and PDGFRA mutations is useful for predicting the effect of imatinib. Resistance to imatinib after an initial response has been reported; secondary point mutations in KIT or PDGFRA that confer imatinib resistance are the most common mechanisms responsible for acquired resistance to imatinib. The continued development of target-specific therapies should increase the probability of cure in most patients with GISTs.     

Clinical and neurophysiological studies with the aldose reductase inhibitor,sorbinil, in symptomatic diabetic neuropathy

Summary The effect of sorbinil (200 mg daily for 4 weeks) was examined in 13 patients, mean age 59.7 years (range 42–72 years), with symptomatic diabetic neuropathy of mean duration 6 years (range 1–18 years). In this double-blind, placebo-controlled crossover trial, studies were made of motor, sensory and autonomic nerve function, severity of painful symptoms and duration of sleep. One patient was withdrawn because of an adverse reaction to sorbinil. In the other 12, constant mean values for glycosylated haemoglobin A₁ between 11% and 12% indicated stable though not ideal diabetic control throughout the study. Example values for nerve conduction velocity on placebo and active treatment were: 44.3 ± 5.9 and 44.8 ± 5.1 metres/s (mean±SD) for median motor nerve, 38.4 ±8.2 and 37.2 ± 7.7 metres/s for median sensory nerve. Thus there was no significant effect of sorbinil on conduction velocity in these or any other of the motor and sensory nerves tested. Abnormal autonomic function was not improved by sorbinil. Subjective pain scores on a 10 cm visual analogue scale were 4.2 ± 2.4 on placebo and 4.3 ± 2.4 after sorbinil. Duration of sleep on placebo and active treatment was 6.1 ±1.6 and 6.2 ±1.7 h/night, respectively. We were not able to detect any beneficial effect of sorbinil on painful diabetic neuropathy in our patients.     

Gastroesophageal reflux symptoms not responding to proton pump inhibitor: GERD,NERD, NARD,esophageal hypersensitivity or dyspepsia?

Gastroesophageal reflux (GER) is a common gastrointestinal process that can generate symptoms of heartburn and chest pain. Proton pump inhibitors (PPIs) are the gold standard for the treatment of GER; however, a substantial group of GER patients fail to respond to PPIs. In the past, it was believed that acid reflux into the esophagus causes all, or at least the majority, of symptoms attributed to GER, with both erosive esophagitis and nonerosive outcomes. However, with modern testing techniques it has been shown that, in addition to acid reflux, the reflux of nonacid gastric and duodenal contents into the esophagus may also induce GER symptoms. It remains unknown how weakly acidic or alkaline refluxate with a pH similar to a normal diet induces GER symptoms. Esophageal hypersensitivity or functional dyspepsia with superimposed heartburn may be other mechanisms of symptom generation, often completely unrelated to GER. Detailed studies investigating the pathophysiology of esophageal hypersensitivity are not conclusive, and definitions of the various disease states may overlap and are often confusing. The authors aim to clarify the pathophysiology, definition, diagnostic techniques and medical treatment of patients with heartburn symptoms who fail PPI therapy.     

Prevalence of and risk factors for HIV-associated neuropathy in Melbourne, Australia 1993-2006

OBJECTIVES: The aim of the study was to describe the prevalence of and risk factors for HIV-associated sensory neuropathy (HIV-SN) in 2006 [the era of stavudine, didanosine and zalcitabine (dNRTI)-sparing highly active antiretroviral therapy (HAART)] and to compare our findings with data obtained in the same clinic in 1993 (pre-HAART) and 2001 (frequent use of dNRTI-containing HAART). METHODS: This was a cross-sectional comparative study using convenience sampling. HIV-positive adults attending a tertiary referral clinic over a 2-week period were screened for HIV-SN using the AIDS Clinical Trials Group screening tool. HIV-SN was defined as present if the patient had both neuropathic symptoms and abnormal signs. Demographic, clinical, laboratory and treatment data were considered as possible risk factors for HIV-SN, and results were compared with data obtained in the same clinic in 1993 and 2001. RESULTS: One hundred patients were screened. The prevalence of HIV-SN was 42%, which was unchanged since 2001 (44%) despite a significant reduction in the use of dNRTIs. HIV-SN remained much more common than in 1993 (42% vs 13%; P<0.0001). The only independent associations with HIV-SN in 2006 were increasing patient age and a history of exposure to either stavudine or indinavir. This compares with 1993 when neuropathy was increased in those with Mycobacterium avium complex infection, and 2001 when patient age and use of stavudine and didanosine were the independent associations with HIV-SN in this clinic. CONCLUSIONS: HIV-SN remained common among ambulatory patients in 2006 (42% prevalence) despite a significant reduction in the use of dNRTIs. In addition to patient age and stavudine exposure, indinavir use may be a risk factor for HIV-SN.     

Structure, inhibitor, and regulatory mechanism of Lyp, a lymphoid-specific tyrosine phosphatase implicated in autoimmune diseases

The lymphoid-specific tyrosine phosphatase (Lyp) has generated enormous interest because a single-nucleotide polymorphism in the gene (PTPN22) encoding Lyp produces a gain-of-function mutant phosphatase that is associated with several autoimmune diseases, including type I diabetes, rheumatoid arthritis, Graves disease, and systemic lupus erythematosus. Thus, Lyp represents a potential target for a broad spectrum of autoimmune disorders. Unfortunately, no Lyp inhibitor has been reported. In addition, little is known about the structure and biochemical mechanism that directly regulates Lyp function. Here, we report the identification of a bidentate salicylic acid-based Lyp inhibitor I-C11 with excellent cellular efficacy. Structural and mutational analyses indicate that the inhibitor binds both the active site and a nearby peripheral site unique to Lyp, thereby furnishing a solid foundation upon which inhibitors with therapeutic potency and selectivity can be developed. Moreover, a comparison of the apo- and inhibitor-bound Lyp structures reveals that the Lyp-specific region S(35)TKYKADK(42), which harbors a PKC phosphorylation site, could adopt either a loop or helical conformation. We show that Lyp is phosphorylated exclusively at Ser-35 by PKC both in vitro and in vivo. We provide evidence that the status of Ser-35 phosphorylation may dictate the conformational state of the insert region and thus Lyp substrate recognition. We demonstrate that Ser-35 phosphorylation impairs Lyp's ability to inactivate the Src family kinases and down-regulate T cell receptor signaling. Our data establish a mechanism by which PKC could attenuate the cellular function of Lyp, thereby augmenting T cell activation.     

Histiocytic neoplasms: Going,going, but not quite gone

BRAF and MEK inhibitors have revolutionised the treatment of patients with high-risk histiocytic neoplasms but does a complete response mean that treatment can be withdrawn? Commentary on: Reiner et al. Outcomes after interruption of targeted therapy in patients with histiocytic neoplasms. Br J Haematol 2023;203:389–394.     

The HMG-CoA inhibitor, simvastatin, triggers in vitro anti-tumour effect and decreases IgM secretion in Waldenstrom macroglobulinaemia

Waldenstrom macroglobulinaemia (WM) is an incurable lymphoplasmacytic lymphoma with secretion of serum monoclonal immunoglobulin M (IgM). We previously showed that patients receiving cholesterol-lowering statins, had the lowest IgM value in a large cohort of patients with WM. Simvastatin, a 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitor, induced inhibition of proliferation, cytotoxic effect and apoptosis in IgM secreting cell lines as well as in primary CD19⁺ WM cells. Interestingly, those effects were reversed by addition of mevalonate and geranylgeranylpyrophosphate, demonstrating that simvastatin inhibited cell growth, survival and IgM secretion on BCWM.1 WM cells by inhibition of geranylgeranylated proteins. Furthermore, simvastatin overcame tumour cell growth induced by co-culture of WM cells with bone-marrow stromal cells. Simvastatin also decreased IgM secretion by BCWM.1 cells at an early time-point that had not affected cell survival. Simvastatin-induced cytotoxicity was preceded by a decrease in Akt (protein kinase B, PKB) and extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathways at 18 h. In addition, simvastatin induced an increase in stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) MAPK followed by caspase-8, -9, -3 and poly(ADP-ribose) polymerase (PARP) cleavages at 18 h, leading to apoptosis. Furthermore, simvastatin enhanced the cytotoxicity induced by bortezomib, fludarabine and dexamethasone. Our studies therefore support our earlier observation of statin-mediated anti-WM activity and provide the framework for future clinical trials testing simvastatin in WM.     

Determinants of Long-Term Outcome of Patients with Reflux-Related Ear, Nose, and Throat Symptoms

Gastroesophageal reflux disease (GERD) is present in up to 75% of patients with chronic refractory ear, nose, and throat (ENT) symptoms, and proton pump inhibitor (PPI) therapy induces symptom relief in the majority of these patients. It has been suggested that endoscopic findings and quantification of esophageal acid exposure may help to predict the long-term outcome of medical therapy, but prospective studies that confirm this hypothesis are lacking. The aim of the present study was to investigate the relationship of endoscopic findings and quantification of reflux with long-term outcome in patients with reflux-related ENT symptoms. One hundred six consecutive patients with chronic refractory unexplained ENT symptoms underwent upper GI endoscopy, 24-hr dual-channel esophageal pH and Bilitec (n = 35) monitoring, and esophageal manometry. Subsequently, all were treated with omeprazole, 20 mg b.i.d., and patients were followed at 2-week intervals until symptom relief. Four weeks later, omeprazole therapy was gradually decreased and the lowest effective omeprazole maintenance dose, if any, was determined. Eighty-one patients (49 men; mean age, 50) experienced a clear or excellent therapeutic response after, on average, 4 weeks of omeprazole, 20 mg b.i.d. In 36 patients (44%; group A), PPI treatment could be stopped completely, 27 patients (33%; group B) required a maintenance dose of omeprazole, 20 mg/day, and 18 patients (22%; group C) required maintenance with omeprazole, 40 mg/day. The prevalence of reflux esophagitis was significantly lower in group A patients, who also had significantly lower distal esophageal acid exposure, proximal esophageal acid exposure, and esophageal duodenogastroesophageal reflux exposure compared to groups B and C. Multivariate analysis identified the presence of esophagitis and pathological distal esophageal acid exposure as risk factors for the need of maintenance therapy. In patients with reflux-related ENT symptoms, initial findings on upper GI endoscopy and 24-hr pH-metry help to predict the need for maintenance therapy.