Suppressive effects of nonsteroidal anti-inflammatory drugs diclofenac sodium, salicylate and indomethacin on delayed rectifier K+-channel currents in murine thymocytes

Brain Leukocytes as the Potential Therapeutic Target for Post-COVID-19 Brain Fog

After recovering from the acute phase of coronavirus disease 2019 (COVID-19), many patients struggle with additional symptoms of long COVID during the chronic phase. Among them, the neuropsychiatric manifestations characterized by a short-term memory loss and inability to concentrate are called "brain fog". Recent studies have revealed the involvement of "chronic neuro-inflammation" in the pathogenesis of brain fog following COVID-19 infection. In the COVID-related brain fog, similarly to neurodegenerative disorders caused by neuro-inflammation, brain leukocytes, such as microglia and lymphocytes, are hyperactivated, suggesting the overexpression of delayed rectifier K⁺-channels (Kv1.3) within the cells. In our previous patch-clamp studies, drugs, such as antihistamines, statins, nonsteroidal anti-inflammatory drugs, antibiotics and anti-hypertensive drugs, suppressed the Kv1.3-channel activity and reduced the production of pro-inflammatory cytokines. Additionally, newer generation antihistamines, antibiotics and corticosteroids strongly stabilize mast cells that directly activate microglia in the brain. Taking such pharmacological properties of these commonly used drugs into account, they may be useful in the treatment of COVID-related brain fog, in which the enhanced innate and adaptive immune responses are responsible for the pathogenesis.

Effects of nonsteroidal anti-inflammatory drugs on ultrasound findings of mRNA COVID-19 vaccine-related lymphadenopathy

BACKGROUND

Previous studies reported axillary lymphadenopathy (LAP) as a side effect of the anti-COVID-19 vaccine. However, the effects of nonsteroidal anti-inflammatory drug (NSAID)s on mRNA COVID-19 vaccine-related LAP have not been investigated.

PURPOSE

We aimed to investigate the effects of NSAIDs on temporal changes in sonographic findings of COVID-19 vaccine-associated LAP.

METHODS

Our single-center retrospective cohort study was conducted between October 2021 and April 2022. We included patients (aged ≥ 18 years) who applied with complaints of swelling in the ipsilateral axillary region after the COVID-19 vaccine and had axillary region ultrasound (US) scans in electronic medical records within 30 days pre-vaccination. The serial US was performed on the third, 10th, and 30th days post-vaccination.

RESULTS

Our study included 38 patients with a median age of 36 (IQR, 32-43) years. In 18 (47.4%) patients used NSAIDs in the early post-vaccination period. Measurements of LAPs on ultrasound scans increased at day 3 post-vaccination compared with pre-vaccination both in NSAID users and non-users. On the 10th day, a statistically insignificant decrease in LAP diameters and cortical thickness was observed in NSAID users compared to non-users. On the post-vaccination 30th day, axillary LAPs regressed similarly in both groups.

CONCLUSION

In our study, post-vaccine NSAID use had no statistically significant effect on the course of axillary LAPs.

Suppressing leukocyte Kv1.3-channels by commonly used drugs: A novel therapeutic target for schizophrenia?

Recent studies revealed the involvement of "chronic inflammation" in the pathogenesis of schizophrenia. In schizophrenia and some neurodegenerative disorders that are caused by inflammation, T-lymphocytes and macrophages were hyperactivated or proliferated in the central nervous system, being accompanied by the overexpression of delayed rectifier K⁺-channels (Kv1.3) within the cells. In our previous basic studies, in addition to nonsteroidal anti-inflammatory drugs (NSAIDs) and statins, antibiotics (clarithromycin, chloroquine), anti-hypertensive drugs (nifedipine, benidipine, diltiazem, verapamil) and anti-allergic drugs (cetirizine, fexofenadine, azelastine, terfenadine) strongly suppressed the Kv1.3-channel activity and pro-inflammatory cytokine production from lymphocytes. Given such pharmacological properties of these commonly used drugs, they may be useful in the treatment of schizophrenia, in which the enhanced cellular immunity and the subsequent release of excessive cytokines are responsible for the pathogenesis.

Does immunosuppressive property of non-steroidal anti-inflammatory drugs (NSAIDs) reduce COVID-19 vaccine-induced systemic side effects?

To help stop the coronavirus disease 2019 (COVID-19) pandemic, vaccines are currently the most critical tool. However, the COVID-19 mRNA vaccines frequently cause systemic side effects shortly after the injection, such as fever, headache and generalized fatigue. In our survey, after receiving the second dose of the COVID-19 vaccine, 80% developed fever, 62% headache and 69% generalized fatigue. Among people who required antipyretics, the average durations of fever and headache were significantly shorter in those who took non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin, loxoprofen and ibuprofen, than those who took acetaminophen. In our patch-clamp studies, NSAIDs effectively suppressed the delayed rectifier K⁺-channel (Kv1.3) currents in T-lymphocytes and thus exerted immunosuppressive effects. Because of this pharmacological property, the use of NSAIDs should be more effective in reducing the vaccine-induced systemic side effects that are caused primarily by the enhanced cellular immunity.

α 1-Adrenergic Receptor Blockade by Prazosin Synergistically Stabilizes Rat Peritoneal Mast Cells

BACKGROUND

Adrenaline quickly inhibits the release of histamine from mast cells. Besides β 2-adrenergic receptors, several in vitro studies also indicate the involvement of α-adrenergic receptors in the process of exocytosis. Since exocytosis in mast cells can be detected electrophysiologically by the changes in the membrane capacitance (Cm), its continuous monitoring in the presence of drugs would determine their mast cell-stabilizing properties.

METHODS

Employing the whole-cell patch-clamp technique in rat peritoneal mast cells, we examined the effects of adrenaline on the degranulation of mast cells and the increase in the Cm during exocytosis. We also examined the degranulation of mast cells in the presence or absence of α-adrenergic receptor agonists or antagonists.

RESULTS

Adrenaline dose-dependently suppressed the GTP-γ-S-induced increase in the Cm and inhibited the degranulation from mast cells, which was almost completely erased in the presence of butoxamine, a β 2-adrenergic receptor antagonist. Among α-adrenergic receptor agonists or antagonists, high-dose prazosin, a selective α 1-adrenergic receptor antagonist, significantly reduced the ratio of degranulating mast cells and suppressed the increase in the Cm. Additionally, prazosin augmented the inhibitory effects of adrenaline on the degranulation of mast cells.

CONCLUSIONS

This study provided electrophysiological evidence for the first time that adrenaline dose-dependently inhibited the process of exocytosis, confirming its usefulness as a potent mast cell stabilizer. The pharmacological blockade of α 1-adrenergic receptor by prazosin synergistically potentiated such mast cell-stabilizing property of adrenaline, which is primarily mediated by β 2-adrenergic receptors.

Second-Generation Histamine H1 Receptor Antagonists Suppress Delayed Rectifier K+-Channel Currents in Murine Thymocytes

BACKGROUND/AIMS

Voltage-dependent potassium channels (Kv1.3) are predominantly expressed in lymphocyte plasma membranes. These channels are critical for the activation and proliferation of lymphocytes. Since second-generation antihistamines are lipophilic and exert immunomodulatory effects, they are thought to affect the lymphocyte Kv1.3-channel currents.

METHODS

Using the patch-clamp whole-cell recording technique in murine thymocytes, we tested the effects of second-generation antihistamines, such as cetirizine, fexofenadine, azelastine, and terfenadine, on the channel currents and the membrane capacitance.

RESULTS

These drugs suppressed the peak and the pulse-end currents of the channels, although the effects of azelastine and terfenadine on the peak currents were more marked than those of cetirizine and fexofenadine. Both azelastine and terfenadine significantly lowered the membrane capacitance. Since these drugs did not affect the process of endocytosis in lymphocytes, they were thought to have interacted directly with the plasma membranes.

CONCLUSIONS

Our study revealed for the first time that second-generation antihistamines, including cetirizine, fexofenadine, azelastine, and terfenadine, exert suppressive effects on lymphocyte Kv1.3-channels. The efficacy of these drugs may be related to their immunomodulatory mechanisms that reduce the synthesis of inflammatory cytokine.

Acute Bronchitis Caused by Bordetella Pertussis Possibly Co-Infected with Mycoplasma Pneumoniae

BACKGROUND Mycoplasma pneumoniae and Bordetella pertussis are among the causative pathogens of human acute bronchitis, which usually has mild symptoms. However, if there is a co-infection, the symptoms often can be prolonged and occasionally can lead to severe respiratory complications. CASE REPORT A 49-year-old Japanese female, who had not been vaccinated for B. pertussis, developed a persistent productive cough which became vigorous, and occasionally caused difficulty breathing and vomiting. Since serum IgM to M. pneumoniae was positive and IgG to B. pertussis was significantly elevated, and there were no findings of pneumonia on a chest x-ray film, we made a diagnosis of acute bronchitis caused by B. pertussis with possible co-infection with M. pneumoniae. The use of garenoxacin, a quinolone derivative, failed to work; however, a macrolide antibiotic clarithromycin dramatically improved her symptoms shortly after its administration. CONCLUSIONS In this patient case, because of the lymphocyte-stimulatory nature of M. pneumoniae and B. pertussis, an increased immunological response was likely to be involved in the pathogenesis of the symptoms. The immunosuppressive effect of clarithromycin was considered to repress the increased lymphocyte activity, facilitating the remission of the disease.

Postrenal acute kidney injury in a patient with unilateral ureteral obstruction caused by urolithiasis: A case report

RATIONALE

In patients with bilateral ureteral obstruction, the serum creatinine levels are often elevated, sometimes causing postrenal acute kidney injury (AKI). In contrast, those with unilateral ureteral obstruction present normal serum creatinine levels, as long as their contralateral kidneys are preserved intact. However, the unilateral obstruction of the ureter could affect the renal function, as it humorally influences the renal hemodynamics.

PATIENT CONCERNS

A 66-year-old man with a past medical history of hypertension and diabetes mellitus came to our outpatient clinic because of right abdominal dullness.

DIAGNOSES

Unilateral ureteral obstruction caused by a radio-opaque calculus in the right upper ureter and a secondary renal dysfunction.

INTERVENTIONS

As oral hydration and the use of calcium antagonists failed to allow the spontaneous stone passage, extracorporeal shock wave lithotripsy (ESWL) was performed.

OUTCOMES

Immediately after the passage of the stone, the number of red blood cells in the urine was dramatically decreased and the serum creatinine level almost returned to the normal range with the significant increase in glomerular filtration rate.

LESSONS

Unilateral ureteral obstruction by the calculus, which caused reflex vascular constriction and ureteral spasm in the contralateral kidney, was thought to be responsible for the deteriorating renal function.

Lymphocyte Kv1.3-channels in the pathogenesis of chronic obstructive pulmonary disease: novel therapeutic implications of targeting the channels by commonly used drugs

In patients with chronic obstructive pulmonary disease (COPD), over-activated T-lymphocytes produce pro-inflammatory cytokines and proliferate in situ in the lower airways and pulmonary parenchyma, contributing substantially to the pathogenesis of the disease. Despite our understanding of the molecular mechanisms by which lymphocytes are activated, we know little about the physiological mechanisms. T-lymphocytes predominantly express delayed rectifier K⁺-channels (Kv1.3) in their plasma membranes and these channels play crucial roles in inducing the lymphocyte activation and proliferation. In the pathogenesis of chronic inflammatory diseases, such as chronic kidney disease (CKD) or inflammatory bowel disease (IBD), these channels, which are overexpressed in proliferating lymphocytes within the inflamed organs, are responsible for the progression of the diseases. Since the over-activation of cellular immunity is also mainly involved in the pathogenesis of COPD, this disease could share similar pathophysiological features as those of CKD or IBD. From a literature review including ours, it is highly likely that the Kv1.3-channels are overexpressed or over-activated in T-lymphocytes isolated from patients with COPD, and that the overexpression of the channels would contribute to the development or progression of COPD. The involvement of the channels leads to novel therapeutic implications of potentially useful Kv1.3-channel inhibitors, such as calcium channel blockers, macrolide antibiotics, HMG-CoA reductase inhibitors and nonsteroidal anti-inflammatory drugs, in the treatment of COPD.

Hydrocortisone and dexamethasone dose-dependently stabilize mast cells derived from rat peritoneum

BACKGROUND

Besides their anti-inflammatory properties, corticosteroid drugs exert anti-allergic effects. Exocytosis of mast cells is electrophysiologically detected as the increase in the whole-cell membrane capacitance (Cm). Therefore, the lack of such increase after exposure to the drugs suggests their mast cell-stabilizing effects.

METHODS

We examined the effects of 1, 10, 100 and 200μM hydrocortisone or dexamethasone on the degranulation from rat peritoneal mast cells. Employing the whole-cell patch-clamp recording technique, we also tested their effects on the Cm during exocytosis.

RESULTS

At relatively lower concentrations (1, 10μM), both hydrocortisone and dexamethasone did not significantly affect the degranulation from mast cells and the increase in the Cm induced by GTP-γ-S. Nevertheless, at higher doses (100, 200μM), these drugs inhibited the degranulation from mast cells and markedly suppressed the GTP-γ-S-induced increase in the Cm.

CONCLUSIONS

Our results provided electrophysiological evidence for the first time that corticosteroid drugs, such as hydrocortisone and dexamethasone, inhibited the exocytotic process of mast cells in a dose-dependent manner. The mast cell-stabilizing effects of these drugs may be attributable to their "non-genomic" action, by which they exert rapid anti-allergic effects.

Clarithromycin Dose-Dependently Stabilizes Rat Peritoneal Mast Cells

BACKGROUND

Macrolides, such as clarithromycin, have antiallergic properties. Since exocytosis in mast cells is detected electrophysiologically via changes in membrane capacitance (Cm), the absence of such changes due to the drug indicates its mast cell-stabilizing effect.

METHODS

Employing the whole-cell patch clamp technique in rat peritoneal mast cells, we examined the effects of clarithromycin on Cm during exocytosis. Using a water-soluble fluorescent dye, we also examined its effect on deformation of the plasma membrane.

RESULTS

Clarithromycin (10 and 100 μM) significantly inhibited degranulation from mast cells and almost totally suppressed the GTP-x03B3;-S-induced increase in Cm. It washed out the trapping of the dye on the surface of mast cells.

CONCLUSIONS

This study provides for the first time electrophysiological evidence that clarithromycin dose-dependently inhibits the process of exocytosis. The mast cell-stabilizing action of clarithromycin may be attributable to its counteractive effect on plasma membrane deformation induced by exocytosis.

Nonsteroidal Anti-Inflammatory Drugs Quickly Resolve Symptoms Associated with EBV-Induced Infectious Mononucleosis in Patients with Atopic Predispositions

Case series

Patient: Female, 24 • Male, 35

Final Diagnosis: EBV-induced infectious mononucleosis

Symptoms: Fever • general malaise • lymphadenopathy

Medication: —

Clinical Procedure: Physical examination and serological testing

Specialty: Infectious diseases

Usefulness of targeting lymphocyte Kv1.3-channels in the treatment of respiratory diseases

T lymphocytes predominantly express delayed rectifier K(+)-channels (Kv1.3) in their plasma membranes. Patch-clamp studies revealed that the channels play crucial roles in facilitating the calcium influx necessary to trigger lymphocyte activation and proliferation. Using selective channel inhibitors in experimental animal models, in vivo studies further revealed the clinically relevant relationship between the channel expression and the development of chronic respiratory diseases, in which chronic inflammation or the overstimulation of cellular immunity in the airways is responsible for the pathogenesis. In chronic respiratory diseases, such as chronic obstructive pulmonary disease, asthma, diffuse panbronchiolitis and cystic fibrosis, in addition to the supportive management for the symptoms, the anti-inflammatory effects of macrolide antibiotics were shown to be effective against the over-activation or proliferation of T lymphocytes. Recently, we provided physiological and pharmacological evidence that macrolide antibiotics, together with calcium channel blockers, HMG-CoA reductase inhibitors, and nonsteroidal anti-inflammatory drugs, effectively suppress the Kv1.3-channel currents in lymphocytes, and thus exert anti-inflammatory or immunomodulatory effects. In this review article, based on the findings obtained from recent in vivo and in vitro studies, we address the novel therapeutic implications of targeting the lymphocyte Kv1.3-channels for the treatment of chronic or acute respiratory diseases.

Roles of lymphocyte kv1.3-channels in the pathogenesis of renal diseases and novel therapeutic implications of targeting the channels

Delayed rectifier K⁺-channels (Kv1.3) are predominantly expressed in T lymphocytes. Based on patch-clamp studies, the channels play crucial roles in facilitating the calcium influx necessary to trigger lymphocyte activation and proliferation. Using selective channel inhibitors in experimental animal models, in vivo studies then revealed the clinically relevant relationship between the channel expression and the pathogenesis of autoimmune diseases. In renal diseases, in which “chronic inflammation” or “the overstimulation of cellular immunity” is responsible for the pathogenesis, the overexpression of Kv1.3-channels in lymphocytes promotes their cellular proliferation and thus contributes to the progression of tubulointerstitial fibrosis. We recently demonstrated that benidipine, a potent dihydropyridine calcium channel blocker, which also strongly and persistently inhibits the lymphocyte Kv1.3-channel currents, suppressed the proliferation of kidney lymphocytes and actually ameliorated the progression of renal fibrosis. Based on the recent in vitro evidence that revealed the pharmacological properties of the channels, the most recent studies have revealed novel therapeutic implications of targeting the lymphocyte Kv1.3-channels for the treatment of renal diseases.

Suppressive effects of diltiazem and verapamil on delayed rectifier K(+)-channel currents in murine thymocytes

BACKGROUND

Lymphocytes predominantly express delayed rectifier K(+)-channels (Kv1.3) in their plasma membranes, and these channels play crucial roles in the lymphocyte activation and proliferation. Since diltiazem and verapamil, which are highly lipophilic Ca(2+) channel blockers (CCBs), exert relatively stronger immunomodulatory effects than the other types of CCBs, they would affect the Kv1.3-channel currents in lymphocytes.

METHODS

Employing the standard patch-clamp whole-cell recording technique in murine thymocytes, we examined the effects of these drugs on the channel currents and the membrane capacitance.

RESULTS

Both diltiazem and verapamil significantly suppressed the peak and the pulse-end currents of the channels, although the effects of verapamil were more marked than those of diltiazem. Both drugs significantly lowered the membrane capacitance, indicating the interactions between the drugs and the plasma membranes.

CONCLUSIONS

This study demonstrated for the first time that CCBs, such as diltiazem and verapamil, exert inhibitory effects on Kv1.3-channels expressed in lymphocytes. The effects of these drugs may be associated with the mechanisms of immunomodulation by which they decrease the production of inflammatory cytokines.

Physiological significance of delayed rectifier K(+) channels (Kv1.3) expressed in T lymphocytes and their pathological significance in chronic kidney disease

T lymphocytes predominantly express delayed rectifier K(+) channels (Kv1.3) in their plasma membranes. More than 30 years ago, patch-clamp studies revealed that the channels play crucial roles in facilitating the calcium influx necessary to trigger lymphocyte activation and proliferation. In addition to selective channel inhibitors that have been developed, we recently showed physiological evidence that drugs such as nonsteroidal anti-inflammatory drugs, antibiotics, and anti-hypertensives effectively suppress the channel currents in lymphocytes, and thus exert immunosuppressive effects. Using experimental animal models, previous studies revealed the pathological relevance between the expression of ion channels and the progression of renal diseases. As an extension, we recently demonstrated that the overexpression of lymphocyte Kv1.3 channels contributed to the progression of chronic kidney disease (CKD) by promoting cellular proliferation and interstitial fibrosis. Together with our in-vitro results, the studies indicated the therapeutic potency of Kv1.3-channel inhibitors in the treatment or the prevention of CKD.

HMG-CoA reductase inhibitors pravastatin, lovastatin and simvastatin suppress delayed rectifier K(+)-channel currents in murine thymocytes

BACKGROUND

Since lymphocytes predominantly express delayed rectifier K(+)-channels (Kv1.3) that trigger lymphocyte activation, statins, which exert immunosuppressive effects, would affect the channel currents.

METHODS

Employing the patch-clamp technique in murine thymocytes, we examined the effects of statins on Kv1.3-channel currents and the membrane capacitance (Cm).

RESULTS

Pravastatin significantly suppressed the pulse-end currents of the channels. Lovastatin and simvastatin also suppressed the peak currents, significantly decreasing the Cm.

CONCLUSIONS

This study demonstrated for the first time that statins inhibit thymocyte Kv1.3-channels. The slow inactivation patterns induced by lovastatin and simvastatin may be associated with their accumulation in the plasma membranes.

Pitting type of pretibial edema in a patient with silent thyroiditis successfully treated by angiotensin II receptor blockade

Patient: Female, 56

Final Diagnosis: Thyroiditis – silent

Symptoms: Palpitations • pretibial pitting edema • short of breath • sweating

Medication: —

Clinical Procedure: —

Specialty: Endocrinology and Metabolic

Differential effects of clarithromycin and azithromycin on delayed rectifier K(+)-channel currents in murine thymocytes

CONTEXT

Lymphocytes predominantly express delayed rectifier K(+)-channels (Kv1.3) in their plasma membranes, and the channels play crucial roles in the lymphocyte activation and proliferation. Since macrolide antibiotics, such as clarithromycin and azithromycin, exert immunomodulatory effects, they would affect the Kv1.3-channel currents in lymphocytes.

OBJECTIVE

This study determined the physiological involvement in the mechanisms of immunomodulation by these antibiotics.

MATERIALS AND METHODS

Employing the standard patch-clamp whole-cell recording technique in murine thymocytes, we examined the effects of 30 and 100 µM clarithromycin and azithromycin on the Kv1.3-channel currents and the membrane capacitance.

RESULTS

Clarithromycin significantly suppressed the peak currents (30 µM, 178 ± 5.6 to 111 ± 2.0 pA/pF; 100 µM, 277 ± 4.4 to 89.6 ± 10 pA/pF) and the pulse-end currents (30 µM, 47.5 ± 2.2% to 15.5 ± 3.3%; 100 µM, 48.5 ± 1.4% to 15.8 ± 1.0%) of thymocyte Kv1.3-channels without significant effects on the membrane capacitance. In contrast, azithromycin did not affect the channel currents. However, it significantly decreased the membrane capacitance (30 µM, 4.68 ± 0.14 to 3.74 ± 0.13 pF; 100 µM, 4.47 ± 0.06 to 3.37 ± 0.08 pF), indicating its accumulation in the plasma membrane.

DISCUSSION AND CONCLUSION

This study demonstrated for the first time that clarithromycin exerts inhibitory effects on thymocyte Kv1.3-channel currents, while azithromycin decreases the membrane capacitance without affecting the channel currents. These differences in the effects of the macrolide antibiotics may reflect differences in the mechanisms of immunomodulation by which they control the production of cytokines.

A case of fitz-hugh-curtis syndrome complicated by appendicitis conservatively treated with antibiotics

A 27-year-old woman developed a low grade fever and increased vaginal discharge that persisted for 2 weeks. Intermittent abdominal pain in the right upper quadrant had been experienced over the previous few days. Due to her clinical manifestations and typical abdominal computed tomography (CT) findings, including hepatic capsular enhancement and hepatomegaly, a diagnosis of Fitz-Hugh-Curtis syndrome was made. The early empirical use of antibiotics, azithromycin and levofloxacin, partially improved her symptoms. However, the low grade fever persisted and additional abdominal pain developed in the right lower quadrant. Based on the radiological evidence of an enlarged appendix with wall thickening, a diagnosis of appendicitis was additionally made, which was thought to occur secondarily to the genital tract infection. Following the administration of antibiotics ceftriaxone and cefditoren pivoxil, her symptoms were completely resolved without the need for any surgical intervention. Here, we report the first case of Fitz-Hugh-Curtis syndrome complicated by appendicitis, which was conservatively managed with antibiotic treatment alone. In this case, the overgrowth of pathogens within the genital tract and their direct penetration into the appendix was thought to be responsible for the development of appendicitis.

Aspirin-induced microscopic surface changes stimulate thrombopoiesis in rat megakaryocytes

During the process of thrombopoiesis, invaginations of the plasma membrane occur in megakaryocytes. Since acetylsalicylic acid (aspirin), the most commonly used anti-inflammatory and antiplatelet drug, interacts with the lipid bilayers of the plasma membranes, this drug would affect the process of thrombopoiesis. In the present study, employing a standard patch-clamp whole-cell recording technique, we examined the effects of aspirin on delayed rectifier K(+)-channel (Kv1.3) currents and the membrane capacitance in megakaryocytes. Using confocal imaging of di-8-butyl-amino-naphthyl-ethylene-pyridinium-propyl-sulfonate (di-8-ANEPPS) staining, we also monitored the membrane invaginations in megakaryocytes. Aspirin suppressed both the peak and the pulse-end currents with a significant increase in the membrane capacitance. Massive di-8-ANEPPS staining after treatment with aspirin demonstrated the impaired membrane micro-architecture of megakaryocytes. This study demonstrated for the first time that aspirin induces microscopic surface changes in megakaryocytes. Such surface changes were thought to stimulate thrombopoiesis in megakaryocytes as detected by the increase in the membrane invaginations.

Overexpression of Delayed Rectifier K(+) Channels Promotes In situ Proliferation of Leukocytes in Rat Kidneys with Advanced Chronic Renal Failure

Leukocytes, such as lymphocytes and macrophages, predominantly express delayed rectifier K⁺ channels (Kv1.3), and the channels play crucial roles in the activation and proliferation of the cells. Since lymphocytes are activated in patients with end-stage renal disease (ESRD), the channels expressed in those cells would contribute to the progression of renal fibrosis in advanced-stage chronic renal failure (CRF). In the present study, using a rat model with advanced CRF that underwent 5/6 nephrectomy followed by a 14-week recovery period, we examined the histopathological features of the kidneys and the leukocyte expression of Kv1.3-channels and cell cycle markers. Age-matched sham-operated rats were used as controls. In the cortical interstitium of advanced CRF rat kidneys, leukocytes proliferated in situ and overexpressed Kv1.3 channel protein in their cytoplasm. Treatment with margatoxin, a selective Kv1.3-channel inhibitor, significantly suppressed the number of leukocytes and the progression of renal fibrosis with a significant decrease in the cortical cell cycle marker expression. This study demonstrated for the first time that the number of leukocytes was dramatically increased in rat kidneys with advanced CRF. The overexpression of Kv1.3 channels in the leukocytes was thought to contribute to the progression of renal fibrosis by stimulating cell cycling and promoting cellular proliferation.

Complete remission of human parvovirus b19 associated symptoms by loxoprofen in patients with atopic predispositions

Two cases of women in their thirties with past histories of atopic dermatitis and allergic rhinitis developed a low grade fever, followed by a butterfly-shaped erythema, swelling of their fingers, and polyarthralgia. Despite such symptoms that overlap with those of systemic lupus erythematosus (SLE), the diagnostic criteria for SLE were not fulfilled. Due to positive results for human parvovirus B19 (HPV-B19) IgM antibodies in the serum, diagnoses of HPV-B19 infection were made in both cases. Although acetaminophen failed to improve their deteriorating symptoms, a nonsteroidal anti-inflammatory drug (NSAID), loxoprofen, completely removed the symptoms immediately after the administration. In those cases, since the patients were predisposed to atopic disorders, an increased immunological response based on the lymphocyte hypersensitivity was likely to be involved in the pathogenesis. The immunomodulatory property of NSAID was thought to repress such lymphocyte activity and thus provided a rapid and sustained remission of the disease.