Effectiveness and safety of deucravacitinib treatment for moderate-to-severe psoriasis in real-world clinical practice in Japan

BACKGROUND

Deucravacitinib is a selective oral tyrosine kinase 2 (TYK2) inhibitor recently approved for psoriasis.

OBJECTIVES

We aimed to evaluate the real-world effectiveness and safety of deucravacitinib for psoriasis.

METHODS

We analyzed 33 Japanese patients with psoriasis (23 with plaque psoriasis, eight with psoriatic arthritis, and two with erythrodermic psoriasis) from January 2023 to October 2023. All patients received deucravacitinib 6 mg daily until week 16.

RESULTS

At week 8, 12, or 16, the achievement rate of PASI 75 was 60.9%, 73.9%, or 78.3%, that of PASI 90 was 13.0%, 39.1%, or 52.2%, that of PASI 100 was 0%, 8.7%, or 13.0%, that of absolute PASI ≤2 was 34.8%, 65.2%, or 78.3%, respectively. The achievement rate of dermatology life quality index 0/1 at week 16 was 42.9%. Fourteen patients (42%) complained pruritus. Peak pruritus-numerical rating scale in patients with pruritus decreased by median [interquartile] 71.4 [50-80] % of baseline at week 2. Adverse events occurred in 18.2% of patients, which were mild and manageable.

CONCLUSIONS

Deucravacitinib for patients with psoriasis was well-tolerated and gave favorable therapeutic effects in the real-world practice. Deucravacitinib treatment rapidly reduced pruritus.

Predictive factors for responders to upadacitinib treatment in patients with atopic dermatitis

BACKGROUND

Janus kinase 1 inhibitor upadacitinib is therapeutically effective for atopic dermatitis (AD). However, predictive factors for high responders to upadacitinib have not been established in real-world clinical practice.

OBJECTIVES

To identify predictive factors for responders to upadacitinib 15 mg or 30 mg, defined as achievers of investigator's global assessment (IGA) 0/1 with ≥ 2-point improvement from basal IGA.

METHODS

A retrospective study was conducted from August 2021 to July 2023 on 159 AD patients treated with upadacitinib 15 mg and 52 patients with 30 mg. Patients in each group were categorized into responders (achievers of IGA 0/1 at week 12) and non-responders (non-achievers). We compared baseline values of clinical and laboratory parameters between responders and non-responders. Logistic regression analysis was used to detect variables predicting responders. Receiver-operating characteristic curves were used for evaluating prediction capabilities of the variables.

RESULTS

In logistic regression analysis, responders to 15 mg upadacitinib were associated with lower total EASI and higher age whereas responders to 30 mg were associated with lower LDH and lower IgE.

CONCLUSIONS

Lower total EASI and higher age may predict responders to upadacitinib 15 mg while lower IgE and lower LDH may predict responders to 30 mg.

Long-term effectiveness and safety of upadacitinib for Japanese patients with moderate-to-severe atopic dermatitis: a real-world clinical study

BACKGROUND

Previous clinical trials presented efficacy and safety of Janus kinase 1 inhibitor upadacitinib through 52 weeks for moderate-to-severe atopic dermatitis (AD).

OBJECTIVES

To assess the effectiveness and safety of upadacitinib through 48 weeks in real-world clinical practice for Japanese AD patients (aged ≥12 years).

METHODS

This retrospective study included 287 patients with moderate-to severe AD treated with 15 mg (n = 216) or 30 mg (n = 71) of upadacitinib daily. Effectiveness was assessed using eczema area severity index (EASI) scores, atopic dermatitis control tool (ADCT), peak pruritus-numerical rating scale (PP-NRS), and investigator's global assessment (IGA). Safety was evaluated through the incidence of treatment-emergent adverse events.

RESULTS

From baseline, EASI, ADCT, PP-NRS, and IGA rapidly reduced at week 4, and the reduction was maintained until week 48 of treatment with upadacitinib at both doses. Achievement rates of EASI 75, EASI 90, and EASI 100 at week 48 were 63.5, 30.2, and 7.9 in 15 mg group, and 77.4, 54.8, and 3.2% in 30 mg group, respectively. Acne and herpes zoster were frequent, but no serious adverse events occurred.

CONCLUSIONS

Upadacitinib was therapeutically effective and tolerable for moderate-to-severe AD through 48 weeks in real-world clinical practice.

Early itch relief with upadacitinib predicts later skin clearance in Atopic dermatitis

BACKGROUND

Though Janus kinase inhibitors such as upadacitinib rapidly relieve itch in atopic dermatitis (AD) patients, how early itch relief impacts later skin clearance is not examined.

OBJECTIVES

This study aims to determine if early itch relief by upadacitinib could predict complete skin clearance in later phases.

METHODS

This retrospective study involved 105 patients with moderate-to-severe AD treated with upadacitinib 15 mg/day. Eczema area and severity index (EASI), atopic dermatitis control tool, and achievement rate of EASI 100 were evaluated at weeks 4, 12, and 24. The threshold of early peak pruritus-numerical rating scale (PP-NRS) predicting later skin clearance was assessed by area under the receiver-operating characteristic curve, and predictors for EASI 100 achievement were determined by logistic regression analysis.

RESULTS

The rate of achieving EASI 100 at week 24 was extremely higher in patients who achieved week 2 PP-NRS ≤ 1 (42.9%) than in non-achievers (1.4%). The logistic regression analysis showed that the achievement of week 2 PP-NRS ≤ 1 and low body mass index were associated with achievement of EASI 100 at weeks 12 and 24.

CONCLUSIONS

The achievement of week 2 PP-NRS ≤ 1 may predict later skin clearance in upadacitinib treatment.

Real-world effectiveness and safety of bimekizumab in Japanese patients with psoriasis: A single-center retrospective study

Bimekizumab, which suppresses both interleukin (IL)-17A and IL-17F, has recently been approved as a biologic for psoriasis. We aimed to evaluate the real-world effectiveness and safety of bimekizumab for psoriasis and to identify predictive factors for its treatment responsiveness. We analyzed 36 Japanese patients with psoriasis (19 with psoriasis vulgaris and 17 with psoriatic arthritis) from May 2022 to September 2023. All patients received bimekizumab (320 mg every 4 weeks) until week 16. Seventeen patients (43.2%) had experienced bio-switch. The median (interquartile range) baseline total psoriasis area and severity index (PASI) was 6 (3.2-20.0). Total PASI rapidly and significantly decreased at week 4 by a median 79.8% from baseline, and gradually decreased thereafter. The PASI on the trunk, and upper and lower limbs rapidly and significantly decreased at week 4 compared to baseline and plateaued thereafter. The neutrophil-to-lymphocyte ratio and neutrophil number significantly decreased at week 16 compared to baseline. At weeks 4, 8, 12, and 16, the achievement rate of absolute PASI ≤2 was 72.2%, 80.6%, 92.9%, and 96.4%, respectively; that of absolute PASI ≤1 was 41.7%, 61.3%, 85.7%, and 82.1%; that of PASI 75 was 55.5%, 52.9%, 69.7%, and 75.8%; that of PASI 90 was 36.1%, 50.0%, 57.6%, and 62.9%; and that of PASI 100 was 19.4%, 38.2%, 51.5%, or 57.6%, respectively. Linear multivariate regression analysis revealed that younger age was associated with a higher percentage reduction of total PASI at weeks 4 and 8. There were no serious or fatal adverse events during treatment. In conclusion, bimekizumab rapidly and remarkably reduced the total PASI together with high achievement rates of absolute PASI ≤1 and ≤2, and with favorable safety in real-world clinical practice. Younger age may be a predictive factor for a good treatment response to bimekizumab.

Total eosinophil count as a biomarker for therapeutic effects of upadacitinib in atopic dermatitis over 48 weeks

Background

Atopic dermatitis (AD) is a chronic skin disease characterized by type 2-skewed immune responses, and significantly influenced by cytokines dependent on Janus kinases (JAKs). Upadacitinib, a JAK1 inhibitor, is effective for moderate-to-severe AD. This study aims to identify biomarkers that reflect long-term therapeutic effects of upadacitinib 15 mg or 30 mg.

Methods

A retrospective study from August 2021 to July 2023 included 213 AD patients treated with upadacitinib 15 mg and 70 AD patients with 30 mg. We analyzed eczema area and severity index (EASI), peak pruritus-numerical rating scale (PP-NRS), serum immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), lactate dehydrogenase (LDH), and total eosinophil count (TEC) at weeks 0, 4, 12, 24, 36, and 48 of treatment.

Results

Both treatments with upadacitinib 15 mg and 30 mg significantly reduced EASI and PP-NRS scores over week 4 to 48 compared to baseline. Upadacitinib 15 mg or 30 mg treatment significantly decreased TEC compared to baseline through week 4 to 36 or week 4 to 48, respectively. The percent reduction of TEC correlated with those of EASI and PP-NRS through week 4 to 48 of treatment with upadacitinib 15 mg, or through week 12 to 48 with 30 mg, respectively. After adjusting for % reductions of other laboratory markers, the significance of correlations was preserved at weeks 36 and 48 of 15 mg treatment, while at weeks 4 and 36 of 30 mg treatment.

Conclusion

The % reduction of TEC correlated with those of EASI and PP-NRS during upadacitinib treatment, indicating its potential as a biomarker reflecting treatment responses to upadacitinib in AD patients. However, the variability of significant correlation during treatment indicates that further inspection is needed for its usefulness in monitoring responses to upadacitinib treatment for AD.

Sustained Effectiveness of Upadacitinib in Moderate-to-Severe Atopic Dermatitis: A 48-Week Real-World Study

Clinical trials and real-world studies have shown the effectiveness of upadacitinib for treating rash and pruritus in patients with atopic dermatitis (AD). This study aimed to determine whether the early reduction in rash or pruritus at week 12 of upadacitinib treatment could be maintained at later treatment stages. This retrospective study involved 227 and 73 patients with moderate-to-severe AD treated with 15 and 30 mg upadacitinib daily, respectively. The eczema area and severity index (EASI) scores, peak pruritus numerical rating scale (PP-NRS), and investigator's global assessment (IGA) were analyzed. At week 12, patients were divided into achievers and non-achievers of EASI 75, 90, 100, absolute EASI ≤ 2, IGA0/1, PP-NRS4, or absolute PP-NRS ≤ 1. Achievement rates for each endpoint were assessed at later time points (weeks 24, 36, and 48) in both groups. Week 12 achievers largely maintained their endpoint achievements until week 48, regardless of dosage (15 mg or 30 mg). Week 12 non-achievers saw an increasing achievement rate of EASI 75 until week 48. The initial reduction in rash and pruritus at week 12 persisted until week 48 with upadacitinib treatment, suggesting potential benefits for patients requiring prolonged treatment despite not achieving EASI 75 at week 12.

Effectiveness of Dose Increase in Upadacitinib from 15 mg to 30 mg for Patients with Moderate-to-Severe Atopic Dermatitis: A Real-World Clinical Practice in Japan

BACKGROUND

Atopic dermatitis is characterized by persistent eczema and pruritus. Janus kinase inhibitors, including upadacitinib, are effective treatments for moderate-to-severe atopic dermatitis. If patients do not respond well to a certain dose of a Janus kinase inhibitor, increasing the dose may improve their treatment responsiveness.

OBJECTIVES

We assessed the outcomes of a dose increase in upadacitinib from 15 mg to 30 mg for Japanese patients with moderate-to-severe atopic dermatitis.

METHODS

In 23 patients who showed insufficient responses to upadacitinib 15-mg treatment, the dose of upadacitinib was increased to 30 mg. We evaluated total Eczema Area and Severity Index (EASI), EASI on the head and neck, trunk, upper, or lower limbs, EASI of erythema, edema/papulation, excoriation, or lichenification, and Peak Pruritus Numerical-Rating Scale at baseline (onset of upadactinib 15 mg), week 0 (time of increase), and weeks 4 and 12 after the increase.

RESULTS

Total EASI, EASI on each anatomical site, EASI of each clinical sign, and Peak Pruritus Numerical-Rating Scale were markedly reduced at weeks 4 or 12 compared with week 0. After the dose increase, the achievement rates of EASI 75 and EASI 90 significantly improved; EASI 75 4.3%, 68.2%, and 66.7%; EASI 90 0%, 18.2%, and 38.1% at weeks 0, 4, and 12, respectively.

CONCLUSIONS

These results suggest that upadacitinib 30 mg can ameliorate rash and pruritus insufficiently improved by upadacitinib 15 mg, and that the dose increase to 30 mg may be considered as a treatment option for patients with atopic dermatitis with a limited response to upadacitinib 15 mg.

Therapeutic effectiveness of upadacitinib on individual types of rash in Japanese patients with moderate-to-severe atopic dermatitis

Atopic dermatitis (AD) is a chronic eczematous disease with various types of rash, erythema, edema/papulation, excoriation, or lichenification. Janus kinase 1 inhibitor upadacitinib is effective for moderate-to-severe AD. We aimed to investigate the therapeutic effects of upadacitinib on each rash type in AD patients in real-world clinical practice. Seventy-two Japanese patients with moderate-to-severe AD were treated with oral upadacitinib 15 mg/day plus topical corticosteroids. The Eczema Area and Severity Index (EASI) scores for erythema, edema/papulation, excoriation, or lichenification on the whole body or on head and neck, upper limbs, lower limbs, or trunk were assessed at weeks 0, 4, and 12 of treatment. The proportions of patients who achieved resolution or at least 75% reduction of EASI from baseline (EASI 75) for individual rash types were calculated at weeks 4 and 12 on the whole body or each anatomical site. The resolution rates for excoriation, erythema, edema/papulation, or lichenification on the whole body were 38.3%, 23.7%, 21.7%, and 8.3% at week 4 and 18.3%, 18.6%, 11.6%, and 13.3% at week 12, respectively. The EASI scores for all rash types significantly decreased at weeks 4 and 12 compared to week 0. The achievement rates of EASI 75 for excoriation, erythema, edema/papulation, or lichenification on the whole body were 67.2%, 66.7%, 49.2%, and 37.7% at week 4 and 57.3%, 65%, 41%, and 41% at week 12, respectively. The achievement rate of EASI 75 for erythema on head and neck at week 4 (45.3%) was lower than that on upper limbs (71%) and on lower limbs (70.8%), and that on head and neck at week 12 (42.2%) was lower than that on lower limbs (69.2%). These results indicate that upadacitinib is effective for all AD rash types, especially for excoriation and erythema, while head-and-neck erythema might be less responsive to upadacitinib.

The differential effects of upadacitinib treatment on skin rashes of four anatomical sites in patients with atopic dermatitis

BACKGROUND

Upadacitinib is an oral Janus kinase (JAK) 1 inhibitor approved in Japan for moderate-to-severe atopic dermatitis (AD), and it provides a high therapeutic efficacy.

OBJECTIVES

We compared the therapeutic effects of upadacitinib on skin rashes of individual anatomical sites, head and neck, upper limbs, lower limbs, and trunk in patients with AD.

METHODS

From August 2021 to December 2022, 65 Japanese patients with moderate-to-severe AD (aged ≥ 12 years) were treated with oral once daily upadacitinib 15 mg plus twice daily topical corticosteroids of moderate-to-strongest classes.

RESULTS

The eczema area and severity indexes (EASIs) of individual sites decreased significantly at weeks 4, 12, and 24 compared to those at week 0 in parallel to total (whole body) EASI. The achievement rates of EASI 75 at week 24 and of EASI 90 at week 12 of lower limbs were significantly higher than those of trunk. The percent reductions of EASI of lower limbs at weeks 12 and 24 were significantly higher than those of head and neck and of trunk.

CONCLUSIONS

Among the four anatomical sites, the treatment responsiveness to upadacitinib in lower limbs appeared the highest, while those in trunk and in head and neck appeared relatively lower.

Effectiveness of switching from baricitinib 4 mg to upadacitinib 30 mg in patients with moderate-to-severe atopic dermatitis: a real-world clinical practice in Japan

BACKGROUND

Atopic dermatitis (AD) is a chronic eczematous disease with severe pruritus. Janus kinase (JAK) inhibitors, upadacitinib, baricitinib, and abrocitinib, are systemic treatments for AD. The outcomes of switching from one JAK inhibitor to another have not been examined.

OBJECTIVES

We assessed the outcomes of switching from baricitinib 4 mg to upadacitinib 30 mg in Japanese patients with moderate-to-severe AD.

METHODS

Twenty patients treated with baricitinib 4 mg, showing insufficient response or adverse events, were switched to treatment with upadacitinib 30 mg. We evaluated total eczema area and severity index (EASI), EASI at head and neck, trunk, upper, or lower limbs, EASI of erythema, edema/papulation, excoriation, or lichenification, and peak pruritus numerical-rating scale (PP-NRS) at baseline (start of baricitinib), weeks 0 (time of switching), and 4 and 12 after switching.

RESULTS

Total EASI, EASI at each anatomical site, EASI of each clinical sign, and PP-NRS were markedly reduced at weeks 4 or 12 compared to week 0. Achievement rates of more than 75% or 90% reduction of EASI from baseline significantly improved after switching.

CONCLUSIONS

Switching from baricitinib 4 mg to upadacitinib 30 mg effectively improved rash and pruritus.

Effectiveness and Safety of Upadacitinib in Combination with Topical Corticosteroids in Adolescent Patients with Moderate-to-Severe Atopic Dermatitis

Purpose

To investigate the therapeutic effectiveness and safety of Janus kinase 1 inhibitor upadacitinib in adolescent patients with atopic dermatitis (AD).

Patients and Methods

This study examined therapeutic effectiveness and safety of upadacitinib for 39 Japanese adolescent patients (aged 12-17 years) diagnosed with moderate-to-severe AD from August 2021 to January 2023. The patients were treated with upadacitinib 15 mg/day plus twice daily topical corticosteroids. Total eczema area and severity index (EASI) or EASI on head and neck, upper limbs, lower limbs, and trunk or for erythema, edema/papulation, excoriation, or lichenification, atopic dermatitis control tool (ADCT), peak pruritus-numerical rating scale (PP-NRS), and laboratory indexes were assessed at weeks 0, 4, and 12 of treatment. Treatment-emergent adverse events were recorded.

Results

Total EASI or EASI on 4 anatomical sites or for 4 rash types, ADCT, and PP-NRS were significantly reduced at week 4 and 12 compared to week 0. The achievement rates at weeks 4 or 12 were 64.1% or 62.5% for EASI 75, 93.5% or 73.1% for ADCT <7-point, and 80.6% or 60% for PP-NRS ≥4-point improvement, respectively, indicating their peak at week 4 and slight decrease at week 12. The percent reduction of EASI for excoriation was higher than that for lichenification or edema/papulation at week 4 or week 12, respectively. The percent reductions of EASI for erythema and edema/papulation on head and neck were lower than those on lower limbs at week 12. Total eosinophil counts (TEC) and IgE reduced at week 4 compared to week 0 while TARC, IgE, TEC, and LDH increased at week 12 compared to week 4.

Conclusion

These results suggest therapeutic effectiveness and tolerability of upadacitinib and support its therapeutic usefulness for adolescent AD patients.

Background factors predicting the occurrence of herpes zoster in atopic dermatitis patients treated with upadacitinib

Upadacitinib, an oral Janus kinase 1 inhibitor approved for treating atopic dermatitis (AD), can cause adverse events such as herpes zoster (HZ) and acne. We aimed to identify background factors predicting the occurrence of HZ and acne during upadacitinib treatment in patients with AD. From August 2021 to December 2022, 112 Japanese patients with moderate-to-severe AD (aged ≥12 years) were treated with upadacitinib 15 mg/day (78 patients) or 30 mg/day (34 patients) plus topical corticosteroids or delgocitinib limited to head and neck for 3-9 months. AD patients with the occurrence of HZ during upadacitinib treatment had higher incidences for history of HZ and of bronchial asthma than those without in the upadacitinib 15 mg, 30 mg, and whole groups. AD patients with occurrence of HZ had higher pretreatment values of lactate dehydrogenase and eczema area and severity index on head and neck compared to those without in the upadacitinib 15 mg and whole groups. Logistic regression analysis revealed that history of HZ was associated with the occurrence of HZ in the upadacitinib 15 mg and whole groups. The proportion of underage patients (<18 years) was higher in patients with occurrence of acne compared to those without in the upadacitinib 30 mg group, but no significant differences were found in the other background factors between the two patient populations. History of HZ may predict the occurrence of HZ during upadacitinib treatment in patients with AD.

Efficacy and safety of baricitinib treatment for moderate to severe atopic dermatitis in real-world practice in Japan

The authors evaluated the efficacy and safety of baricitinib, a Janus kinase 1/2 inhibitor, for atopic dermatitis (AD) in real-world practice. From August 2021 to September 2022, 36 patients aged ≥15 years with moderate to severe AD were treated with oral baricitinib 4 mg/day plus topical corticosteroids. Baricitinib improved clinical indexes; the percent reduction at weeks 4 and 12 was a median of 69.19% and 69.98% for the Eczema Area and Severity Index (EASI), 84.52% and 76.33% for the Atopic Dermatitis Control Tool, and 76.39% and 64.58% for Peak Pruritus Numerical Rating Score, respectively. The achievement rate of EASI 75 was 38.89% and 33.33% at weeks 4 and 12, respectively. The percent reduction of EASI in the head and neck, upper limbs, lower limbs, and trunk was 56.9%, 68.3%, 80.7%, and 62.5% at week 12, respectively, with a significant difference between the head and neck versus the lower limbs. Baricitinib decreased thymus and activation-regulated chemokine, lactate dehydrogenase, and total eosinophil count at week 4. Baseline EASI of the head and neck negatively correlated with percent reduction of EASI at week 4, while baseline EASI of the lower limbs positively correlated with percent reduction of EASI at week 12. Treatment-emergent adverse events included elevation of creatine phosphokinase (11.1%), herpes labialis (5.6%), furuncle (8.3%), and exacerbation of AD (1%), without serious treatment-emergent adverse events. In this real-world study, baricitinib was well tolerated for patients with AD and achieved therapeutic effects comparable to those in clinical trials. High baseline EASI of the lower limbs might predict good treatment response at week 12, while high baseline EASI of the head and neck might predict poor treatment response at week 4 in baricitinib treatment for AD.

Effects of Biologic Therapy on Laboratory Indicators of Cardiometabolic Diseases in Patients with Psoriasis

Psoriasis is associated with cardiometabolic and cardiovascular diseases. Biologic therapy targeting tumor necrosis factor (TNF)-α, interleukin (IL)-23, and IL-17 may improve not only psoriasis but also cardiometabolic diseases. We retrospectively evaluated whether biologic therapy improved various indicators of cardiometabolic disease. Between January 2010 and September 2022, 165 patients with psoriasis were treated with biologics targeting TNF-α, IL-17, or IL-23. The patients' body mass index; serum levels of HbA1c, total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol, triglyceride (TG), and uric acid (UA); and systolic and diastolic blood pressures were recorded at weeks 0, 12, and 52 of the treatment. Baseline psoriasis area and severity index (week 0) positively correlated with TG and UA levels but negatively correlated with HDL-C levels, which increased at week 12 of IFX treatment compared to those at week 0. UA levels decreased at week 12 after ADA treatment compared with week 0. HDL-C levels decreased 52 weeks after IXE treatment. In patients treated with TNF-α inhibitors, HDL-C levels increased at week 12, and UA levels decreased at week 52, compared to week 0. Thus, the results at two different time points (at weeks 12 and 52) were inconsistent. However, the results still indicated that TNF-α inhibitors may improve hyperuricemia and dyslipidemia.

Left ventricular outflow tract pressure gradient changes after carvedilol-disopyramide cotherapy in a cat with hypertrophic obstructive cardiomyopathy

Disopyramide reduces the left ventricular outflow tract (LVOT) pressure gradient and improves symptoms in humans with hypertrophic obstructive cardiomyopathy (HOCM). However, the efficacy of disopyramide in cats has not been reported. We treated a cat with HOCM with carvedilol and disopyramide cotherapy and monitored the changes in LVOT flow velocity and N-terminal pro B-type natriuretic peptide (NT-proBNP) concentration. A 10-month-old neutered male Norwegian Forest cat was referred with a moderate systolic cardiac murmur. Echocardiography revealed thickening of the left ventricular wall, systolic anterior motion of the mitral valve leaflets, and turbulent aortic flow in the LVOT at systole. The LVOT flow velocity was 5.6 m/s. The plasma NT-proBNP concentration exceeded 1,500 pmol/L. The cat was diagnosed with HOCM and the β-blocker carvedilol was started and gradually increased to 0.30 mg/kg, bid. After 57 days, the LVOT flow velocity (4.8 m/s) and plasma NT-proBNP concentration (870 pmol/L) had decreased but remained elevated. Therefore, disopyramide was added at 5.4 mg/kg po bid and increased to 10.9 mg/kg po bid after 22 days. After 141 days of carvedilol and disopyramide treatment, the systolic anterior motion of the mitral valve leaflets had disappeared and the LVOT flow velocity and plasma NT-proBNP concentration had decreased to 0.7 m/s and 499 pmol/L, respectively. No adverse effect has been observed during the follow-up. Disopyramide might relieve feline LVOT obstruction after only partial response to a beta-blocker. Further large-scale studies are required to investigate the efficacy and safety of disopyramide use in cats with moderate to severe HOCM.

Long-term follow-up of collateral pathways established after lymphadenectomy in rats

A collateral pathway established after lymphadenectomy could play an important role in long-term lymphedema treatment. The present study investigated alterations of lymph dynamics 1 year after lymphadenectomy using indocyanine green fluorescent lymphography to determine if a collateral pathway may be used for long-term lymphedema treatment. Wistar rats were anaesthetized and lymph nodes were excised at the inguinal and popliteal fossae. The treated hind limb was evaluated by fluorescent lymphography between 10 weeks and 6 months and between 6 months and 1 year postoperatively. Fluorescent lymphography demonstrated a lymphatic pathway to the ipsilateral axillary fossa in all rats 1 year after lymphadenectomy. Some capillary branches in the paths leading to the ipsilateral axillary fossa were dilated and tortuous. In addition, areas in which a fluorescent signal was not visible were increased in the thigh. In conclusion, the collateral pathway did not appear to be only for temporary use to compensate for drainage from the edematous limb but appears more stable as a component of a compensating lymphatic system. These new dilated vessels, although functional at this point, may still be susceptible to disturbance by further alteration to the lymph vessels.

Serial magnetic resonance imaging study of posterior cruciate ligament reconstruction or augmentation using hamstring tendons

PURPOSE

The purpose of this study was to analyze serial changes in the magnetic resonance imaging (MRI) signals of autograft hamstrings single bundle posterior cruciate ligament (PCL) reconstruction and the effects of remnant preservation (augmentation).

MATERIAL AND METHODS

Twenty-two isolated PCL injuries were arthroscopically reconstructed or augmented with hamstring tendons. MRI scans were obtained at 3, 6, and 12 months, and prior to the second-look arthroscopy (average 20.7 months). The patients were divided into 2 groups by remnant preservation: five PCL reconstructions after PCL remnant resection (Group Rec) (23%), and 17 reconstructions preserving the remnant (Group Aug) (77%). The 22 patients were also divided in two groups depending on the location of the PCL tear. There were 9 knees with proximal tear (Type P) (41%) and 13 knees with distal tear (Type D) (59%). The signal intensity and fiber continuity of 4 zones (proximal, middle, distal intra-articular and tibial tunnel zones) were evaluated by the Mariani score.

RESULTS

The average MRI evaluation score gradually increased from 6 months through the final MRI. The intra-articular part of the graft exhibited slower maturation (12 months - final scan) as compared with the tibial tunnel (6-12 months). The distal zone underwent better maturation than the proximal or middle zones at all points. In the proximal zone, the score for Group Aug was significantly higher than Group Rec. In the proximal zone, the Type D score with a proximally-preserved remnant was significantly higher than Type P without a proximal remnant.

CONCLUSIONS

The hamstring tendons require more than 1 year to achieve low-signal intensity. PCL remnant has a beneficial effect on the maturation of the hamstring graft.

LEVEL OF EVIDENCE IV

therapeutic case series.

In vitro amyloidogenic peptides of galectin-7: possible mechanism of amyloidogenesis of primary localized cutaneous amyloidosis

Pathogenesis of primary localized cutaneous amyloidosis (PLCA) is unclear, but pathogenic relationship to keratinocyte apoptosis has been implicated. We have previously identified galectin-7, actin, and cytokeratins as the major constituents of PLCA. Determination of the amyloidogenetic potential of these proteins by thioflavin T (ThT) method demonstrated that galectin-7 molecule incubated at pH 2.0 was capable of binding to the dye, but failed to form amyloid fibrils. When a series of galectin-7 fragments containing β-strand peptides were prepared to compare their amyloidogenesis, Ser(31)-Gln(67) and Arg(120)-Phe(136) were aggregated to form amyloid fibrils at pH 2.0. The rates of aggregation of Ser(31)-Gln(67) and Arg(120)-Phe(136) were dose-dependent with maximal ThT levels after 3 and 48 h, respectively. Their synthetic analogs, Phe(33)-Lys(65) and Leu(121)-Arg(134), which are both putative tryptic peptides, showed comparable amyloidogenesis. The addition of sonicated fibrous form of Ser(31)-Gln(67) or Phe(33)-Lys(65) to monomeric Ser(31)-Gln(67) or Phe(33)-Lys(65) solution, respectively, resulted in an increased rate of aggregation and extension of amyloid fibrils. Amyloidogenic potentials of Ser(31)-Gln(67) and Phe(33)-Lys(65) were inhibited by actin and cytokeratin fragments, whereas those of Arg(120)-Phe(136) and Leu(121)-Arg(134) were enhanced in the presence of Gly(84)-Arg(113), a putative tryptic peptide of galectin-7. Degraded fragments of the galectin-7 molecule produced by limited trypsin digestion, formed amyloid fibrils after incubation at pH 2.0. These results suggest that the tryptic peptides of galectin-7 released at neutral pH, may lead to amyloid fibril formation of PLCA in the intracellular acidified conditions during keratinocyte apoptosis via regulation by the galectin-7 peptide as well as actin and cytokeratins.

Effects and cost of glycyrrhizin in the treatment of upper respiratory tract infections in members of the Japanese maritime self-defense force: Preliminary report of a prospective, randomized, double-blind, controlled, parallel-group, alternate-day treatment assignment clinical trial

BACKGROUND

Upper respiratory tract infections (URTIs) account for at least half of all acute illnesses. Specific antiviral therapy has not been developed against most respiratory viruses thought to cause URTIs. The pharmacologic action of glycyrrhizin has been shown to produce anti-inflammatory activity, modulation of the immune system, inhibition of virus growth, and inactivation of viruses.

OBJECTIVE

The aim of this study was to assess the tolerability, efficacy, and cost of glycyrrhizin in improving the severity and duration of signs and symptoms of URTIs. The primary end point was tolerability, and the secondary and points included improvement in signs and symptoms of URTI and cost.

METHODS

Members of the Japanese Maritime Self-Defense Force (SDF) treated for URTIs from January 2002 to May 2002 in the SDF Etajima Hospital (Hiroshima, Japan) were eligible for this prospective, randomized, double-blind, controlled, parallel-group, alternate-day treatment assignment study. All patients in this study fulfilled the following enrollment criteria: admitted to the hospital on the first arrival day as an outpatient; fever (body temperature <38.0°C) with signs and symptoms of URTI (headache, sore throat, rhinorrhea, pharyngitis); and had not received antibiotics or oseltamivir phosphate for 4 weeks before the study. Patients who were admitted on an even day received an IV drip infusion of 40 mL of glycyrrhizin (0.2%) and 500 mL of lactated Ringer's solution daily during hospitalization (glycyrrhizin group). Patients who were admitted on an odd day received an IV drip infusion of 500 mL/d of lactated Ringer's solution only (control group). Adverse effects were assessed by the physicians during hospitalization, using patient interview and laboratory analysis.

RESULTS

Forty-one consecutive patients entered the study; 15 patients (15 men, 0 women; mean [SD] age, 25.2 [1.5] years) were assigned to the glycyrrhizin group and 269 patients (24 men, 2 women; mean [SD] age, 22.6 [0.9] years) were assigned to the control group. The 2 groups were similar in terms of baseline characteristics. The mean duration of hospitalization was shorter (P = 0.01), the mean maximum body temperature 24 to 48 hours after admission was less (P = 0.05), and the cost of therapy (P = 0.03) was less in the glycyrrhizin group than the control group. No AEs were reported.

CONCLUSIONS

In this study of hospitalized patients with URTIs, glycyrrhizin therapy was associated with a shorter hospitalization, lower-grade fever, and lower cost of therapy compared with controls, showing that it may be beneficial to patients with URTIs without acute bacterial infections.

Alterations of lymph flow after lymphadenectomy in rats revealed by real time fluorescence imaging system

Secondary lymphedema is one of the sequella of cancer treatment that in inadequately understood. The purpose of the present study is to investigate lymphedema formation and to explore the escape routes for excess interstitial fluid using lymphadenectomy in a rat model. In twelve Wistar rats, lymph nodes in the right inguinal and popliteal fossas were completely removed and lymph vessels carefully ligated. After operation, treated hind limbs were evaluated by indocyanine green lymphography and circumferential measurement. Both evaluations were performed from day 3 to ten weeks. Approximately 2 to 3 weeks after operation, a network-like pattern of the fluorescent signal appeared around the surgical site which then transitioned into a linear pattern in the lower abdomen. Videorecordings identified fluorescent flow moving from the lower abdomen to the ipsilateral axillary lymph node and in some rats, the network-like pattern was also observed to pass transversely over the suprapubic region to the contralateral inguinal lymph nodes. The network-like pattern on the lower abdomen and the linear pattern to the axillary fossa were seen continuously to the end of observation. Circumferential measurements of the treated hind limbs increased initially and then declined over time. This imaging system may be useful to detect early changes in lymphatic flow before swelling occurs and further study is needed.

AGE-modified collagens I and III induce keratinocyte terminal differentiation through AGE receptor CD36: epidermal-dermal interaction in acquired perforating dermatosis

To clarify the molecular mechanism underlying the transepidermal extrusion of dermal collagen in acquired perforating dermatosis (APD) associated with diabetes mellitus and renal failure, we studied the interaction between advanced glycation end product (AGE)-modified extracellular matrix proteins and keratinocytes (KCs) in a cell culture system. The expression of involucrin (INV) and keratin 10 was significantly enhanced in normal human KCs grown on AGE-modified collagen I or III compared with cells grown on unmodified collagen I or III. Glycated collagens I and III preferentially induced the expression of AGE receptor CD36, but not of other AGE receptors. KCs induced to terminal differentiation demonstrated markedly elevated CD36 expression. Glycated collagen I- and III-induced INV expression was partially blocked by the anti-CD36 antibody (Ab). These substrates also induced epidermal matrix metalloproteinase 9 (MMP-9) expression. Lesional skin from APD patients reacted moderately or strongly with the anti-CD36 Ab as well as the anti-MMP-9 Ab in the epidermal cells surrounding the collagenous materials being eliminated. These results suggest that exposing KCs to AGE-modified interstitial collagen (types I and III) by scratching induces terminal differentiation of KCs via the AGE receptor (CD36), leading to the upward movement of KCs together with glycated collagen.

Cutaneous mucinous nodule in a patient with rheumatoid arthritis

We report a cutaneous mucinous nodule on the inflamed elbow joint in a patient with rheumatoid arthritis (RA). The lesion is clinically characterized by a continuous flow of mucinous exudates from the nodule, and histologically by an extensive mucin deposition and proliferations of the fibroblastic cells and mononuclear cells. The histological findings suggest the histogenesis of this unique nodule is related to extralesional proliferation of synovial lining cells consisting of monocyte-macrophage lineage cells and fibroblast-like cells which potentially produce synovial fluid. Four patients have been hitherto reported in the published work and all of them have been associated with RA. The condition may be one of the characteristic skin manifestations of RA.

Leukocytapheresis treatment for pyoderma gangrenosum

A 42-year-old man presented with painful erythema with pustules and multiple small ulcers on the shins. He had suffered from ulcerative colitis (UC) and received oral glucocorticosteroid and salicylazosulfapyridine therapies for 7 years. Biopsy of the lesion demonstrated mixed cellular infiltrates with dominant neutrophils. The patient was diagnosed with pyoderma gangrenosum (PG) and underwent leukocytapheresis (LCAP), an extracorporeal leucocyte removal therapy, once a week for 5 weeks without changing the doses of the oral medications. The skin lesions as well as clinical signs of UC rapidly improved after LCAP, and no recurrence was seen during a follow-up period. There were no major complications during LCAP. LCAP will provide an effective and safe tool for the treatment of PG.

[Midterm restenosis of freestyle valved conduit in an adult tetralogy of Fallot]

We report a case of midterm restenosis of freestyle valved conduit implanted between the right ventricle and the pulmonary artery. A 69-year-old woman visited our hospital with dyspnea and general fatigue and was diagnosed as tetralogy of Fallot. Total corrective surgery including patch closure of ventricular septal defect was performed using the freestyle valve with the Hemashield prothesis to reconstruct the right ventricle to the pulmonary artery. The catheterization revealed almost normal right ventricular pressure on 40th postoperative day, but the opening of the valve was limited. Twenty-two months later she visited our hospital with severe right heart failure. The pressure gradient over the valve was 122 mmHg and the leaflet of the freestyle valve was markedly thickened causing severe stenosis. Use of the freestyle valve for the right ventricular out flow tract reconstruction has to be further studied.

A novel mechanism associated with idiopathic ventricular fibrillation (IVF) mutations R1232W and T1620M in human cardiac sodium channels

Two mutations associated with idiopathic ventricular fibrillation (IVF) are localized within extracellular loops between segments DIIIS1-S2 (R1232W) and DIVS3-S4 (T1620M) of the human cardiac sodium channel (hNav1.5) alpha-subunit. We studied wild-type hNav1.5 channels and hNav1.5 channels with the R1232W/T1620M double mutation expressed in Xenopus oocytes using the cell-attached macropatch technique. We demonstrate that these mutations destabilize the fast-inactivated state (described with a two-state first-order reaction model) by decreasing reaction valence, accelerating recovery, and slowing the onset of fast inactivation, collectively resulting in delayed decay of macroscopic currents. R1232W/T1620M mutations in hNav1.5 channels also significantly increase steady-state channel availability, indicating that mutated channels occupy the slow inactivated state less than hNav1.5 channels. Under the stress of repetitive depolarizing pulses, R1232W/T1620M channels demonstrate less use-dependent current reduction compared to wild-type channels. We propose that increased channel availability coupled with destabilized fast inactivation contributes to the pathological effect of R1232W/T1620M mutations, and leads to increased excitability of cardiac tissue in vivo.

A single residue differentiates between human cardiac and skeletal muscle Na+ channel slow inactivation

Slow inactivation determines the availability of voltage-gated sodium channels during prolonged depolarization. Slow inactivation in hNa(V)1.4 channels occurs with a higher probability than hNa(V)1.5 sodium channels; however, the precise molecular mechanism for this difference remains unclear. Using the macropatch technique we show that the DII S5-S6 p-region uniquely confers the probability of slow inactivation from parental hNa(V)1.5 and hNa(V)1.4 channels into chimerical constructs expressed in Xenopus oocytes. Site-directed mutagenesis was used to test whether a specific region within DII S5-S6 controls the probability of slow inactivation. We found that substituting V754 in hNa(V)1.4 with isoleucine from the corresponding position (891) in hNa(V)1.5 produced steady-state slow inactivation statistically indistinguishable from that in wild-type hNa(V)1.5 channels, whereas other mutations have little or no effect on slow inactivation. This result indicates that residues V754 in hNa(V)1.4 and I891in hNa(V)1.5 are unique in determining the probability of slow inactivation characteristic of these isoforms. Exchanging S5-S6 linkers between hNa(V)1.4 and hNa(V)1.5 channels had no consistent effect on the voltage-dependent slow time inactivation constants [tau(V)]. This suggests that the molecular structures regulating rates of entry into and exit from the slow inactivated state are different from those controlling the steady-state probability and reside outside the p-regions.

Pretibial cyst formation after anterior cruciate ligament reconstruction using auto hamstring grafts: two case reports in a prospective study of 89 cases

Eighty-nine cases after anterior cruciate ligaments (ACL) reconstruction were followed prospectively with magnetic resonance imaging (MRI). The patients were examined using axial and sagittal MRI at least twice during the postoperative evaluation of reconstructed ACL. Two cases of pretibial cyst formation were observed. At the time of cyst formation, neither patient had any subjective or objective evidence of knee instability. The cyst of one case communicated with the intra-articular. The minimum follow-up period after the surgical excision was 9 months, with no evidence of recurrence. We might speculate that the critical period for cyst formation in both patients occurred at less than 12 months after their ACL reconstruction. We concluded that the cyst formation was most likely due to incomplete graft tendon incorporation within the osseous tunnel.

The delay in recovery from fast inactivation in skeletal muscle sodium channels is deactivation

1. Using macropatch techniques, we tested the assumption that deactivation underlies the observed delay in the onset to recovery from fast inactivation by comparing open-state deactivation to recovery delay for rat skeletal muscle mutations R1441C and R1441P. 2. Deactivation kinetics from the open state were determined from the exponential decay of tail currents. R1441C and R1441P prolonged open-state deactivation, with the greatest effect produced by R1441P. 3. Delays in the onset to recovery from fast inactivation for R1441P and for R1441C were abbreviated compared to those for rSkM1. Recovery delay was longer in R1441P than R1441C at voltages more negative than -110 mV. Recovery from inactivation exhibited a voltage dependence which, unlike delay, saturated at depolarized voltages. Recovery rate constants were increased to a similar extent for R1441C and R1441P at -150 to -120 mV compared to rSkM1. 4. These results indicate that the delay in the onset to recovery from fast inactivation in skeletal muscle sodium channels is due to deactivation. Lessening of charge immobilization for R1441C and R1441P may contribute to observed biophysical defects underlying the hyperexcitability of muscle fibers containing paramyotonia congenita mutations. The second stage of recovery from fast inactivation may be affected differentially by these mutations.

Evaluation of the internal thoracic arterial graft patency by the transthoracic Doppler method under continuous intravenous infusion of adenosine triphosphate disodium

Usefulness of the Doppler method under continuous infusion of adenosine triphosphate disodium (ATP) for improvement of accuracy in the diagnosis of the left internal thoracic arterial graft (LITA) patency was examined using transthoracic ultrasonic echocardiography. 1) Influence of ATP on the Doppler velocity in a graft was examined in 7 patients with good LITA grafts using physiological saline as the control. In the ATP group, 80 mg of ATP was dissolved in 20 ml physiological saline and continuously infused at 0.14 mg/kg/min. In the saline group, an equal volume of physiological saline was administered and the blood flow velocity in the LITA was recorded continuously by the transthoracic Doppler method from the supraclavicular fossa approach. Results; ATP administration increased the blood flow velocity in the LITA and the rate of increase was 48.3% for systolic peak velocity, 111% for diastolic peak velocity, 64.4% for systolic time velocity integral and 99% for diastolic time velocity integral indicating particularly high rates of increase in diastolic components. The diastolic/systolic peak velocity ratio or diastolic fraction did not increase significantly. In the saline group, none of the parameters showed a change. 2) Angiographic findings of the LITA were compared with the measurement values of the diastolic components by the Doppler method to examine usefulness of diastolic component measurement with ATP infusion for diagnosis of LITA patency. Subjects were 19 patients with good LITA (group A) and 8 patients with bad LITA (group B). Results; while there were significant differences in the mean baseline diastolic peak velocity, mean diastolic time velocity integral and mean diastolic fraction between the groups, overlapping was seen in individual cases. However, the inter-group differences were more distinct by ATP infusion and the borderline values were 30 cm/sec for diastolic peak velocity and 10 for diastolic time velocity integral. 3) Reliability of the diagnosis for LITA patency by measuring the diastolic components using the Doppler method with ATP infusion was examined and compared with the angiographic findings as the gold standard. Subjects were 27 patients and the diagnostic criteria for good LITA were set at 30 cm/sec for diastolic peak velocity and 10 for diastolic time velocity integral. Results; sensitivity and specificity of the Doppler method with ATP infusion were 100% for diagnosis of LITA patency by measuring the diastolic components. Conclusion, in diagnosis of LITA patency by the transthoracic ultrasonic cardiography, diagnostic accuracy was improved by measuring the diastolic parameters under continuous infusion of ATP.

Effect of cerebrospinal fluid shunting on experimental syringomyelia: magnetic resonance imaging and histological findings

The histological changes associated with syringomyelia after reduction of the syrinx size were investigated after cerebrospinal fluid shunting in experimental syringomyelia in the rabbit. Five weeks after syringomyelia was induced by the injection of kaolin into the cisterna magna in Japanese white rabbits, ventriculosubgaleal shunting or syringoepidural shunting were performed. After 1 week magnetic resonance (MR) imaging and histological examination were then carried out. Five of 11 shunted animals showed postoperative reduction of syrinx size on MR imaging. Grossly, some specimens showed cavity collapse and parenchymal healing, and others showed a small residual syrinx in the dorsal horn. The most dramatic histological changes occurred in the gray matter. Specimens with syrinx collapse showed rarefaction and tearing of the gray matter, with mild glial reaction. The edematous gray matter showed both degeneration and regeneration, with neuronal processes surrounded by edema fluid. Reactive astrocytes were observed mainly at the margin of the residual syrinx. Some astrocytic processes invested the extraaxonal space and gray matter lacked supportive tissue. Greater reduction of the syrinx after shunting operation was correlated with more regeneration and less degeneration, and the white matter was edematous and histological changes were milder. Syrinx shrinkage occurred after shunting in this experimental model of syringomyelia. The selective vulnerability of gray matter even after shunting may explain discrepancies between imaging findings and clinical features in this disease. The study supports the potential benefit from early treatment, considering the associated morphological findings of regeneration.

Beneficial effect of basic fibroblast growth factor on the repair of full-thickness defects in rabbit articular cartilage

The effects of exogenous basic fibroblast growth factor (bFGF) on the repair of full-thickness cartilage defects were examined. Four-millimeter diameter, cylindrical defects were made in rabbit articular cartilage and were filled with human recombinant bFGF. The addition of bFGF to the defect induced the formation of a thick cartilage layer composed of chondrocytes and a metachromatic-stained matrix after 6 weeks. The score of the bFGF-treated tissue, as evaluated by a semiquantitative histological scale, was significantly higher than that of the untreated tissue. At 24 weeks, the cartilage-like matrix that contained the proteoglycans and type II collagen was thicker in the bFGF-treated tissue than in the untreated tissue. Immunohistochemical analysis of the tissues at 6-12 weeks with an anti-bFGF monoclonal antibody suggested that a single application of bFGF increased the number of differentiating chondrocytes that synthesized bFGF at a high level. In contrast, immunostaining of the tissues at 6-12 weeks with a monoclonal antibody against proliferating cell nuclear antigen showed that the number of proliferating cells in the bFGF-treated tissue was fewer than in the untreated tissue. These findings suggest that administration of bFGF into cartilagenous defects promotes the differentiation of chondrocytes and their matrix synthesis, and that this growth factor is useful for improving cartilage repair.

Appearance of anterior cruciate ligament autografts in their tibial bone tunnels on oblique axial MRI

The objective of this study was to observe the changing appearance of human anterior cruciate ligament (ACL) grafts in their tibial bone tunnels by MRI using oblique axial images. One-hundred and eight knees in 75 patients were studied by MRI at 1-33 months after arthroscopic ACL reconstructions using double-looped, autogenous semitendinosus and/or gracilis tendons. Knees with poor stability were excluded from this study. The examinations were performed at 0.2T with spin echo proton density and T2-weighted oblique axial images. Appearances of grafts were mainly described on spin echo proton density images based upon time after surgery. The grafts appeared as homogeneous, low signal intensity areas in the bone tunnels at 1 month after the surgery. Ring-shaped low signal intensity areas were observed along the wall of the bone tunnels in the 2- to 3-month group. In many grafts from this group, each tendinous bundle appeared as a low signal area separated by a high signal intensity area. In all cases in the 4- to 6-month group, the thickness of the ring-shaped low signal intensity area had increased, whereas the thickness of the high signal intensity area had decreased. In almost all of the cases, the interior of the bone tunnel gradually became a homologous low signal intensity region by 7 to 12 months after the surgery. According to these results, it is suggested that the maturation of the tendon-bone interface was completed from 6 to 12 months after the ACL reconstruction.

Differential effects of homologous S4 mutations in human skeletal muscle sodium channels on deactivation gating from open and inactivated states

1. The outermost charged amino acid of S4 segments in the alpha subunit of human skeletal muscle sodium channels was mutated to cysteine in domains I (R219C), II (R669C), III (K1126C), and IV (R1448C). Double mutations in DIS4 and DIVS4 (R219C/R1448C), DIIS4 and DIVS4 (R669C/R1448C), and DIIIS4 and DIVS4 (K1126C/R1448C) were introduced in other constructs. Macropatch recordings of mutant and wild-type (hSkM1-wt) skeletal muscle sodium channels expressed in Xenopus oocytes were used to measure deactivation kinetics from open or fast inactivated states. 2. Conductance (voltage) curves (G (V)) derived from current (voltage) (I (V)) relations indicated a right-shifted G (V) relationship for R669C and for R669C/R1448C, but not for other mutations. The apparent valency was decreased for all mutations. Time-to-peak activation at -20 mV was increased for R1448C and for double mutations. 3. Deactivation kinetics from the open state were determined from the monoexponential decay of tail currents. Outermost charge-to-cysteine mutations in the S4 segments of domains III and IV slowed deactivation, with the greatest effect produced by R1448C. The deactivation rate constant was slowed to a greater extent for the DIII/DIV double mutation than that calculated from additive effects of single mutations in each of these two domains. Mutation in DIIS4 accelerated deactivation from the open state, whereas mutation in DIS4 had little effect. 4. Delays in the onset to recovery from fast inactivation were determined to assess deactivation kinetics from the inactivated state. Delay times for R219C and R669C were not significantly different from those for hSkM1-wt. Recovery delay was increased for K1126C, and was accelerated for R1448C. 5. Homologous charge mutations of S4 segments produced domain-specific effects on deactivation gating from the open and from the fast inactivated state. These results are consistent with the hypothesis that translocations of S4 segments in each domain during deactivation are not identical and independent processes. Non-identical effects of these mutations raise several possibilities regarding deactivation gating; translocation of DIVS4 may constitute the rate-limiting step in deactivation from the open state, DIVS4 may be part of the immobilizable charge, and S4 translocations underlying deactivation in human skeletal muscle sodium channel may exhibit co-operativity.

Characterization of a novel Ras-binding protein Ce-FLI-1 comprising leucine-rich repeats and gelsolin-like domains

Ras proteins are conserved from yeasts to mammals and implicated in regulation of the actin cytoskeleton. The flightless-1 (fli-1) gene of Drosophila melanogaster and its homologs in Caenorhabditis elegans and humans encode proteins (FLI-1) comprising a fusion of a leucine-rich repeats (LRRs) domain and a gelsolin-like domain. This LRRs domain is highly homologous to those of three proteins involved in Ras-mediated signaling; Saccharomyces cerevisiae adenylyl cyclase, C. elegans SUR-8, and mammalian RSP-1. Here we report that the LRRs domain of C. elegans FLI-1 (Ce-FLI-1) associates directly with Ras (Kd = 11 nM) and, when overexpressed, suppresses the heat shock sensitive phenotype of yeast cells bearing the activated RAS2 gene (RAS2(Val-19)). Further, the gelsolin-like domain of Ce-FLI-1 is shown to possess a Ca2+-independent G-actin-binding activity as well as F-actin-binding and -severing activities. FLI-1 may be involved in regulation of the actin cytoskeleton through Ras.

Voltage sensors in domains III and IV, but not I and II, are immobilized by Na+ channel fast inactivation

Using site-directed fluorescent labeling, we examined conformational changes in the S4 segment of each domain of the human skeletal muscle sodium channel (hSkM1). The fluorescence signals from S4 segments in domains I and II follow activation and are unaffected as fast inactivation settles. In contrast, the fluorescence signals from S4 segments in domains III and IV show kinetic components during activation and deactivation that correlate with fast inactivation and charge immobilization. These results indicate that in hSkM1, the S4 segments in domains III and IV are responsible for voltage-sensitive conformational changes linked to fast inactivation and are immobilized by fast inactivation, while the S4 segments in domains I and II are unaffected by fast inactivation.

Effects of prelesioned peripheral nerve graft on nerve regeneration in the rat spinal cord

OBJECTIVE

The aim of this study was to examine the effects of prelesioned peripheral nerve grafts on central nerve regeneration compared with the freshly transected peripheral nerve grafts in the dorsal funiculus of the rat spinal cord.

METHODS

The experimental paradigm consisted of ligating the common peroneal nerve at the midthigh level for 7 days, while the adjacent tibial nerve was left intact. Numerous Schwann cells appeared accompanying regenerating axons in the proximal stump of the ligated nerve. The proximal stumps of the ligated (prelesioned) common peroneal nerve and the intact (untreated) tibial nerve were excised as one tissue block and autografted into the dorsal funiculi of the upper cervical cord. The graft was placed so that the prelesioned common peroneal nerve was positioned on the left dorsal funiculus and the untreated tibial nerve was positioned to the right of the midsagittal plane. Nerve regeneration was examined by light and transmission electron microscopy 1 to 16 weeks after grafting, comparing the effectiveness of prelesioned and untreated nerve grafts.

RESULTS

Numerous regenerating axons were observed in the caudal border of both grafts 1 to 2 weeks after grafting. Astrocyte proliferation was suppressed in the prelesioned grafts compared to the untreated grafts. Four to 16 weeks later, the number of regenerating axons was approximately 10-fold as large in the prelesioned grafts as in the untreated grafts. The regenerating axons were myelinated by Schwann cells. Astrocytic glial scar formation was inconspicuous in the prelesioned grafts, whereas it was prominent in the untreated grafts. Schwann cells were contiguous with astrocytes along regenerating axons, forming a continuous conduit from the central to peripheral nerve microenvironments for the outgrowth of regenerating axons.

CONCLUSION

The prelesioned peripheral nerve graft is more effective than the untreated graft in suppressing astrocytic scar formation and in supporting the outgrowth of regenerating axons in the dorsal funiculus of rat spinal cord.

MR evaluation of human anterior cruciate ligament autograft on oblique axial imaging

PURPOSE

The purpose was to observe the changing MR appearance of stable anterior cruciate ligament (ACL) grafts on oblique axial images.

METHOD

Fifty-five knees in 44 patients were studied with MRI 1-54 months after arthroscopic ACL reconstruction with double-looped autogenous semitendinosus and gracilis tendons. Knees with poor stability were excluded from this study. Examinations were performed at 0.2 T with SE proton density and T2-weighted sagittal and oblique axial images.

RESULTS

High signal intensity areas covered the grafts 1-3 months after surgery. The high signal subsequently extended into the intertendinous bundles. The entire graft gradually became a low signal intensity bundle again after 12 months. Grafts were classified by their appearance on the oblique axial images.

CONCLUSION

We conclude that high signal intensity can be seen within stable ACL grafts.

A defect in skeletal muscle sodium channel deactivation exacerbates hyperexcitability in human paramyotonia congenita

1. Paramyotonia congenita (PC) is a human hereditary disorder wherein missense mutations in the skeletal muscle sodium channel lead to cold-exacerbated muscle hyperexcitability. The most common site for PC mutations is the outermost arginine of domain i.v. segment 4 (human R1448, rat R1441). 2. We examined the rat homologues of two PC mutants with changes at this site: R1441P and R1441C. The R-->P mutation leads to the most clinically severe form of the disease. Since PC has so far been attributed to defects in fast inactivation, we expected the R-->P substitution to have a more dramatic effect on fast inactivation than R-->C. Both mutants (R1441P and R1441C), however, had identical rates and voltage dependence of fast inactivation and activation. 3. R1441P and R1441C also had slowed deactivation, compared with wild-type, raising the possibility that slowed deactivation, in combination with defective fast inactivation, might be a contributing cause of paramyotonia congenita. Furthermore, deactivation was slower in R1441P than in R1441C, suggesting that the worse phenotype of the human R-->P mutation is due to a greater effect on deactivation, and supporting our hypothesis that slowed sodium channel deactivation contributes to paramyotonia congenita. 4. We show that the downstroke of the muscle action potential produced a sodium tail current, and thus slowed deactivation opposes repolarization and therefore leads to hyperexcitability. Hyperexcitability due to slowed deactivation, which has previously been overlooked, also predicts the temperature sensitivity of PC, which has otherwise not been adequately explained.

Basic fibroblast growth factor promotes extension of regenerating axons of peripheral nerve. In vivo experiments using a Schwann cell basal lamina tube model

Schwann cell basal lamina tubes serve as attractive conduits for regeneration of peripheral nerve axons. In the present study, by using basal lamina tubes prepared by in situ freeze-treatment of rat saphenous nerve, the effects of exogenously applied basic fibroblast growth factor (bFGF) on peripheral nerve regeneration was examined 2 and 5 days after bFGF administration. Regenerating axons were observed by light and electron microscopy using PGP9.5-immunohistochemistry for specific staining of axons. In addition, the localizations of bFGF and its receptor (FGF receptor-1) were examined by immunohistochemistry using anti-bFGF antibody and anti-FGF receptor-1 antibody, respectively. Regenerating axons extended further in the bFGF-administered segment than in the bFGF-untreated control segment. Electron microscopy showed that regenerating axons grew out unaccompanied by Schwann cells. Findings concerning angiogenesis and Schwann cell migration were very similar between the bFGF treated and control nerve segment. bFGF-immunoreactivity was not detected in the control nerve segment. In contrast, bFGF-immunoreactivity was detected on the basal lamina tubes as well as on the plasmalemma of regenerating axons facing the basal lamina in the bFGF treated nerve segment up to 5 days after administration, suggesting that exogenous bFGF can be retained in the basal lamina for several days after administration. FGF receptor was detected on the plasma membrane of regenerating axons where they abutted the basal lamina. These results indicate that bFGF could promote the extension of early regenerating axons by directly influencing the axons, but not via Schwann cells or angiogenesis.

Remyelination in the rat dorsal funiculus following demyelination by laser irradiation

Excimer laser (KrF excimer laser, 248 nm wavelength) was used to damage cellular components in the dorsal funiculus at the lumbar level (L2) of the rat spinal cord. An open lesion was not found at the irradiation site on the spinal cord. However, the cytological examination revealed that cellular components were damaged to the depth of 200-500 microm from the pial surface. The characteristic feature was that at the border of the lesion, many axons remained naked but intact after their myelin sheaths had been completely disintegrated. Such naked axons were subsequently remyelinated by mature or immature glial cells. Mature oligodendrocytes, while retaining their cytoplasmic processes connected with the myelin sheaths of unaffected axons, extended new cytoplasmic processes on nearby naked axons and made new myelin sheaths around them. In contrast, 7 days after the irradiation, numerous immature glial cells appeared in association with naked axons, and some of them were differentiated into oligodendrocytes forming thin myelin sheaths on naked axons. These findings suggest that demyelinated axons can cause the proliferation and probably dedifferentiation of the oligodendrocyte lineage. The use of lasers provides a unique experimental model of demyelination and remyelination in the central nervous system of adult mammals.

Prevalence of fatty liver in Japanese children and relationship to obesity. An epidemiological ultrasonographic survey

The prevalence of fatty liver in children is unknown and its relationship to obesity is poorly defined. The present study of 810 northern Japanese children (4-12 years old) determined the prevalence of fatty liver in the pediatric population and its relationship to obesity. Diagnosis of fatty liver was based on established real-time ultrasonographic criteria. The overall prevalence of fatty liver was 2.6% and was higher for boys (3.4%) than for girls (1.8%), although not statistically significant (P = 0.15). Fatty liver was found in children as young as 6 years of age. There was no significant association between the prevalence of fatty liver and height (physical growth). There was a strong positive correlation between fatty liver prevalence and established obesity indices: Rohrer's Index--chi 2 linear trend = 59.2, P < 0.0001; body mass index--chi 2 linear trend = 91.6, P < 0.0001; and age-gender-adjusted Japanese standard index of weight for height--chi 2 linear trend = 93.2, P < 0.0001. However, direct measurement of abdominal subcutaneous fat thickness by ultrasonography was the best predictor of fatty liver: chi 2 linear trend = 159, P < 0.0001. These results indicate that fatty liver may develop very early in life, and there is a direct relationship between degree of obesity and fatty liver in children.