Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Strain, cell density, and nutrient condition affect patterns of diurnal vertical migration and superoxide production in a red-tide alga

A red tide occurs when cell densities of autotrophic microalgae and some heterotrophic protists increase dramatically and thereby change the color of the sea. Red tides sometimes have negative impacts on human activities, such as fisheries and tourism. Most red-tide flagellates display diurnal vertical migration (DVM) in which cells normally migrate upward during the day and downward at night. This behavior promotes active growth, due to the effective acquisition of nutrients and light, as well as population density increase and cell aggregation. However, the factors and their interactions influencing DVM remain to be clarified, such that no algorithm exists that can precisely simulate the DVM pattern and the development of a red tide in the field. Chattonella marina complex (hereafter Chattonella) is a representative microalga of harmful red tides and some previous studies has suggested that Chattonella's DVM plays important roles in development of a red tide. Chattonella can produce a large amount of superoxide (•O₂ ^-), which is responsible for the regulation of various physiological processes as well as its toxicity against microorganisms and animals. In the present study, we examined the effects of strain, growth phase, cell density, and nutrient deficiency on the pattern of DVM. In addition, we also measured the •O₂ ^- level in most experiments to assess the relationship between DVM and •O₂ ^- production. Some strains displayed clear DVM, whereas others aggregated at the surface all day in a fixed condition. Strains' DVM patterns did not show a relationship with •O₂ ^- production. Moreover, the DVM became less clear at high cell density and in nitrogen- or phosphorus-depleted conditions. Although a previous study reported that the •O₂ ^- production rate increased during the light period and decreased during the dark period, regardless of cell density, the diurnal pattern of •O₂ ^- became less clear at a higher cell density in a Chattonella strain used in the present study. Our findings indicate that DVM and •O₂ ^- production by a Chattonella population composed of various strains can change across developmental phases and environmental conditions. This characteristic may produce adaptability in species and increase the chances of a massive population increase.

The NAD Kinase Slr0400 Functions as a Growth Repressor in Synechocystis sp. PCC 6803

NADP+, the phosphorylated form of nicotinamide adenine dinucleotide (NAD), plays an essential role in many cellular processes. NAD kinase (NADK), which is conserved in all living organisms, catalyzes the phosphorylation of NAD+ to NADP+. However, the physiological role of phosphorylation of NAD+ to NADP+ in the cyanobacterium Synechocystis remains unclear. In this study, we report that slr0400, an NADK-encoding gene in Synechocystis, functions as a growth repressor under light-activated heterotrophic growth conditions and light and dark cycle conditions in the presence of glucose. We show, via characterization of NAD(P)(H) content and enzyme activity, that NAD+ accumulation in slr0400-deficient mutant results in the unsuppressed activity of glycolysis and tricarboxylic acid (TCA) cycle enzymes. In determining whether Slr0400 functions as a typical NADK, we found that constitutive expression of slr0400 in an Arabidopsis nadk2-mutant background complements the pale-green phenotype. Moreover, to determine the physiological background behind the growth advantage of mutants lacking slr04000, we investigated the photobleaching phenotype of slr0400-deficient mutant under high-light conditions. Photosynthetic analysis found in the slr0400-deficient mutant resulted from malfunctions in the Photosystem II (PSII) photosynthetic machinery. Overall, our results suggest that NADP(H)/NAD(H) maintenance by slr0400 plays a significant role in modulating glycolysis and the TCA cycle to repress the growth rate and maintain the photosynthetic capacity.

Nutrient deficiency stimulates the production of superoxide in the noxious red-tide-forming raphidophyte Chattonella antiqua

The raphidophyte Chattonella antiqua is a single-celled alga that forms 'red tides' in coastal areas. C. antiqua produces superoxide anions (O₂^-), the excessive production of which has been associated with fish mortality. It is suggested that putative NADPH oxidase in the outer membrane oxidizes intracellular NADPH to produce O₂^- and secrete it externally. Earlier studies revealed that photosynthetic electron transport, a major producer of NADPH in photosynthetic organisms, is involved in the production of O₂^- in C. antiqua but the details of the O₂^- production mechanism have yet to be elucidated. Since nutrient deficiency adversely affects the formation of blooms of C. antiqua, in this study, we examined the effects of nutrient deficiency on O₂^- production in C. antiqua. When cells were grown under nitrogen (N)- or phosphorus (P)-deficient conditions, the production of O₂^- was stimulated. In particular, the extracellular levels of O₂^- under N- or P-deficient conditions were high during the dark period when photosynthetic activities in terms of actual quantum efficiency and photochemical quenching were low. The extracellular levels of O₂^- under the nutrient-deficient conditions were unaffected by the presence of 3-(3,4-dichlorophenyl)-1,1‑dimethylurea (DCMU), an inhibitor of photosynthetic electron transport, but decreased when the nutrients were present. Furthermore, the intracellular ratio of NADPH to NADP⁺ under N- or P-deficient conditions was higher than that under nutrient-replete conditions. These observations suggest that another metabolic pathway, independent of photosynthesis, provides NADPH for the production of O₂^- under nutrient deficiency.

Extracellular secretion of superoxide is regulated by photosynthetic electron transport in the noxious red-tide-forming raphidophyte Chattonella antiqua

The raphidophyte Chattonella antiqua is a noxious red-tide-forming alga that harms fish culture and the aquatic environment. Chattonella antiqua produces and secretes superoxide anions (O₂^-), and excessive secretion of O₂^- into the water has been associated with fish mortality. It is known that strong light stimulates the production of O₂^- in Chattonella spp. but the mechanism of the light-induced production of O₂^- remains to be clarified. In the present study, we examined the effects of light on extracellular levels of O₂^- and photosynthesis in C. antiqua. Extracellular levels of O₂^- rose during growth under high-intensity light, and the level of O₂^- was correlated with the photosynthetic parameter qP, which reflects the rate of transport of electrons downstream of photosystem II. The production of O₂^- was inhibited in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea, an inhibitor of photosynthetic electron transport, suggesting that reducing power derived from electron transport might be required for the production of O₂^-. By contrast, the production of O₂^- was enhanced in the presence of glycolaldehyde, an inhibitor of the Calvin-Benson cycle, suggesting that the accumulation of NADPH might stimulate the production of O₂^-. Thus, it is likely that the production of O₂^- is regulated by photosynthesis in C. antiqua.

Identification of the Novel Tooth-Specific Transcription Factor AmeloD

Basic-helix-loop-helix (bHLH) transcription factors play an important role in various organs' development; however, a tooth-specific bHLH factor has not been reported. In this study, we identified a novel tooth-specific bHLH transcription factor, which we named AmeloD, by screening a tooth germ complementary DNA (cDNA) library using a yeast 2-hybrid system. AmeloD was mapped onto the mouse chromosome 1q32. Phylogenetic analysis showed that AmeloD belongs to the achaete-scute complex-like ( ASCL) gene family and is a homologue of ASCL5. AmeloD was uniquely expressed in the inner enamel epithelium (IEE), but its expression was suppressed after IEE cell differentiation into ameloblasts. Furthermore, AmeloD expression showed an inverse expression pattern with the epithelial cell-specific cell-cell adhesion molecule E-cadherin in the dental epithelium. Overexpression of AmeloD in dental epithelial cell line CLDE cells resulted in E-cadherin suppression. We found that AmeloD bound to E-box cis-regulatory elements in the proximal promoter region of the E-cadherin gene. These results reveal that AmeloD functions as a suppressor of E-cadherin transcription in IEE cells. Our study demonstrated that AmeloD is a novel tooth-specific bHLH transcription factor that may regulate tooth development through the suppression of E-cadherin in IEE cells.

The combined use of US and MR imaging for the diagnosis of masses in the parotid region

Purpose: To evaluate the usefulness of the combination of the two non-invasive modalities US and MR imaging to diagnose masses in the parotid region.

Material and Methods: The US and MR findings of 21 patients with parotid masses were analyzed retrospectively by two radiologists without any clinical or histopathological information. The specific points evaluated were location, shape, margin, internal architecture, and intensity level on both US and MR, posterior echo enhancement on US, and capsule-like lining of the tumor on MR.

Results: The findings concerning the shape and margin on US and MR were in fairly good agreement. Concerning the findings of the internal architecture, US could reveal the minute structures of the tumor while MR demonstrated differences in the signal intensities of histological tissue types of the various tumors. The posterior echo enhancement on US and the capsule-like lining on MR of the tumors were also useful for the diagnosis.

Conclusion: Our results suggest that the combination of US and MR is useful for examining soft tissue masses in the parotid region to make a more accurate diagnosis, and not just differentiate malignant lesions from those which are benign.

Development of an improved RT-PCR for specific detection of spring viraemia of carp virus

Spring viraemia of carp (SVC) is a rhabdovirus infection, which has a significant economic impact in pond cultures of carp in Europe and western Independent States of the former Soviet Union. The causative agent of SVC, spring viraemia of carp virus (SVCV), has been divided into four subgroups, Ia, Ib, Ic and Id, on the basis of glycoprotein (G) protein gene sequences. In this study, a new primer set was designed from a G gene sequence of SVCV to identify the four subtypes of SVCV by reverse transcription polymerase chain reaction (RT-PCR). The specific PCR products of 369 bp were amplified from 15 SVCV isolates of all four subtypes. However, pike fry rhabdovirus (PFRV), which is antigenically related to SVCV, and other viruses antigenically related to SVCV and PFRV were not amplified. The four subtypes of SVCV were specifically amplified by the RT-PCR. Furthermore, the detection limit of the RT-PCR was 7.1 × 10(2) copies/reaction, and it was not influenced by the addition of RNA extracted from fish tissues. The RT-PCR will be applied not only to RNA extracted from viral suspensions, but also from fish tissue. It will contribute to rapid identification of SVCV in fish with clinical signs of SVC.

Pathogenesis of acute and chronic diseases caused by cyprinid herpesvirus-3

The pathogenesis of cyprinid herpesvirus-3 (CyHV-3) was studied using different lineages of carp/koi. After exposure to the virus, infected cells were first found in the skin by histopathology and by in situ hybridization. The epidermis of the skin was most severely damaged and often sloughed off in the fish sampled on days 5 through 8, and the fish that were highly sensitive to the virus died within 8 or 10 days after infection. Serum osmolality of the infected fish, particularly just before death, was significantly lower, suggesting that the osmotic shock consequent on the damage to the skin was the direct cause of the acute deaths. On the other hand, clinical and histopathological observations indicate that the carp of a less sensitive lineage most probably died of viral encephalitis around 3 weeks after infection. For these fish, the largest number of infected cells was found in the central nervous system (CNS) sampled on day 12. A substantial amount of viral genome was found in the CNS of carp surviving more than 1 year after the infection. Thus, the CNS is probably a major target for CyHV-3, and the virus can persistently infect the CNS, presumably establishing latency.

A new method for displaying the lingual artery using high-resolution three-dimensional phase-contrast magnetic resonance angiography

The aim of this study was to display the lingual artery superimposed on the anatomical image and to confirm its course and relation to the adjacent structures, noninvasively. Nineteen volunteers participated in the magnetic resonance imaging (MRI) study and one was excluded for excessive movement during scanning. A three-dimensional phase-contrast sequence (3D-PC) of magnetic resonance angiography (MRA) was used for vessel images, and a 3D-T1 high-resolution volume examination (THRIVE) was used for anatomical images. Colour-coded vessel images from 3D-PC MRA were superimposed on the 3D volume anatomical images, and the arterial course and relation to the adjacent structures were confirmed with multiplanar reconstructed cross-sectional (MPR) images. 3D-PC MRA images visualized the lingual artery in all 18 subjects and the sublingual artery in 14 subjects. In seven of 18 cases the bilateral sublingual arteries were shown to run side by side but had no contact with the sublingual veins. They ran together with the sublingual veins in four cases. Three cases showed irregular patterns. The bilateral sublingual arteries could not be identified in four cases. 3D-PC MRA images of the lingual artery superimposed on the anatomical images may be clinically useful to confirm its course and relationship to the adjacent structures before surgery, in order to prevent haemorrhage.

(1-->3)-beta-D-glucan in patients with pulmonary aspergilloma

To elucidate the role of (1→3)-β-D-glucan in pulmonary aspergilloma, serum concentrations of (1→3)-β-D-glucan were measured repeatedly for as long as 10 months in eight patients. In four patients with inactive disease, concentrations of (1→3)-β-D-glucan were in the normal range.The concentrations of (1→3)-β-D-glucan increased in two patients, although the disease was inactive. This increase might show the earliest stage of the invasive process of the disease. In two other patients with active disease, (1→3)-β-D-glucan increased. Other parameters, such as galactomannan, immunodiffusion and a radio-allergosorbent test, as well as inflammatory m arkers such as C-reactive protein and the leukocyte count, did not show any consistent tendency in regard to the activity of the disease. Thus, a (1→3)-β-D-glucan assay may add valuable data for evaluating the disease activity and understanding the disease process of pulmonary aspergilloma.

Quantitative evaluation of vascularity within cervical lymph nodes using Doppler ultrasound in patients with oral cancer: relation to lymph node size

OBJECTIVES

The aim of this study was to quantitatively evaluate the relationship between vascularity within lymph nodes and lymph node size on Doppler ultrasound images of patients with oral cancer.

METHODS

A total of 310 lymph nodes (86 metastatic, 224 benign) from 63 patients with oral cancer were classified into 4 groups according to their short axis diameters: Group 1, short axis diameters of 4-5 mm; Group 2, 6-7 mm; Group 3, 8-9 mm; and Group 4, ≥ 10 mm. Vascular and scattering indices of lymph nodes on Doppler ultrasound images were analysed quantitatively. The vascular index was defined as the ratio of blood flow area to the whole lymph node area and the scattering index was defined as the number of isolated blood flow signal units.

RESULTS

For metastatic lymph nodes, the vascular index was highest in Group 1 and decreased as lymph node size increased. The vascular index of benign lymph nodes did not differ significantly among the four groups. The vascular index of metastatic lymph nodes was significantly higher than that of benign lymph nodes in Group 1. For metastatic lymph nodes, the scattering index increased as lymph node size increased and was significantly higher than that of benign lymph nodes in Groups 2-4.

CONCLUSIONS

An increase in vascularity is a characteristic of Doppler ultrasound findings in small metastatic lymph nodes. As the metastatic lymph node size increases, blood flow signals become scattered, and the scattering index increases.

Evaluation of T2 values and apparent diffusion coefficient of the masseter muscle by clenching

OBJECTIVE

The aim of this study was to evaluate the changes in T2 values and apparent diffusion coefficient (ADC) in the masseter muscle by clenching in healthy volunteers.

METHODS

37 volunteers were enrolled in the study. We measured bite force using pressure-sensitive paper and a T2 map. The ADC map was obtained at rest, during clenching, immediately after and 5 min after clenching. The spin-echo sequence was used to calculate T2, and single-shot spin-echo echo planar imaging was used to calculate the ADC. The motion-probing gradients (MPGs) were applied separately along the posterior-to-anterior (PA), right-to-left (RL) and superior-to-inferior (SI) directions, with b values of 0, 300 and 600 s mm(-2) in each direction. ADC-PA, ADC-RL, and ADC-SI values were obtained, and we calculated the ADC-iso for the mean diffusivity.

RESULTS

There were no significant differences between the stronger and weaker sides of bite force before, during or 5 min after clenching for T2 and ADC. The bite force had little effect on these parameters; thus, we used the average of the two sides for the following analyses. Time course analysis of ADC-iso, ADC-PA, ADC-RL and ADC-SI demonstrated a marked increase after clenching and a rapid decrease immediately after clenching, although they did not completely return to the initial values; however, the change in ADC-RL was significantly greater than those in ADC-PA or ADC-SI (P<0.001 each). The changes in T2 were similar to those of ADC, although not as marked.

CONCLUSIONS

ADC (especially ADC-RL) was altered by contraction of the masseter muscle.

Distribution and species composition of juvenile and adult scombropids (Teleostei, Scombropidae) in Japanese coastal waters

Two scombropid fishes, Scombrops boops and Scombrops gilberti, are closely related and commercially important species in Japan. These species are often confused in commercial markets because of their morphological similarity. In this study, scombropid specimens collected from various Japanese coastal waters were subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis and phylogenetic analysis of the 16S rRNA gene in mitochondrial DNA. These analyses showed that all the scombropid specimens collected from localities in the Sea of Japan were identified as S. boops, whereas those from the Pacific Ocean included two species, S. boops and S. gilberti. Almost all juvenile (<200 mm standard body length, S(L)) S. gilberti originated from the Pacific coastal waters of the northern Japan, whereas adults (>400 mm S(L)) were found only in deep water off the Izu Peninsula to the Izu Islands. This suggests that S. gilberti might migrate extensively during its life cycle. In addition, differences in the number of specimens and the distribution between the two species suggest that S. gilberti is less abundant than S. boops in Japanese waters.

Genotyping of Edwardsiella ictaluri isolates in Japan using amplified-fragment length polymorphism analysis

AIM

The major objective of the present study was to clarify genetic relationship of isolates of Edwardsiella ictaluri in Japan, which was first found from ayu Plecoglossus altivelis in Japanese rivers in 2007.

METHODS AND RESULTS

Ten isolates of Edw. ictaluri in 2007-2008 from ayu and the 1 isolate from bagrid catfish Pelteobagrus nudiceps in Japan were subjected to amplified-fragment length polymorphism (AFLP) analysis. The strains isolated from catfish in United States (ATCC strains) or Indonesia were used as reference strains. The AFLP profiles were all the same among the isolates from Japan, while the polymorphic DNA bands were observed among the strains from United States or Indonesia. The isolates from Japan and Indonesia constituted a genogroup different from the ATCC strains on a dendrogram constructed from the AFLP profiles.

CONCLUSION

No DNA polymorphisms were found among Japanese Edw. ictaluri isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

A single clonality of the Edw. ictaluri isolates in Japan suggests the single source of the organism, and the infection in ayu is in the early stage of epidemics.

Injection of a recombinant AAV serotype 2 into canine skeletal muscles evokes strong immune responses against transgene products

Using murine models, we have previously demonstrated that recombinant adeno-associated virus (rAAV)-mediated microdystrophin gene transfer is a promising approach to treatment of Duchenne muscular dystrophy (DMD). To examine further therapeutic effects and the safety issue of rAAV-mediated microdystrophin gene transfer using larger animal models, such as dystrophic dog models, we first investigated transduction efficiency of rAAV in wild-type canine muscle cells, and found that rAAV2 encoding beta-galactosidase effectively transduces canine primary myotubes in vitro. Subsequent rAAV2 transfer into skeletal muscles of normal dogs, however, resulted in low and transient expression of beta-galactosidase together with intense cellular infiltrations in vivo, where cellular and humoral immune responses were remarkably activated. In contrast, rAAV2 expressing no transgene elicited no cellular infiltrations. Co-administration of immunosuppressants, cyclosporine and mycophenolate mofetil could partially improve rAAV2 transduction. Collectively, these results suggest that immune responses against the transgene product caused cellular infiltration and eliminated transduced myofibers in dogs. Furthermore, in vitro interferon-gamma release assay showed that canine splenocytes respond to immunogens or mitogens more susceptibly than murine ones. Our results emphasize the importance to scrutinize the immune responses to AAV vectors in larger animal models before applying rAAV-mediated gene therapy to DMD patients.

Adeno-associated virus vector-mediated gene transfer into dystrophin-deficient skeletal muscles evokes enhanced immune response against the transgene product

Duchenne muscular dystrophy (DMD) is an X-linked, lethal muscular disorder caused by a defect in the DMD gene. AAV vector-mediated micro-dystrophin cDNA transfer is an attractive approach to treatment of DMD. To establish effective gene transfer into skeletal muscle, we examined the transduction efficiency of an AAV vector in skeletal muscles of dystrophin-deficient mdx mice. When an AAV vector encoding the LacZ gene driven by a CMV promoter (AAV-CMVLacZ) was introduced, beta-galactosidase expression markedly decreased in mdx muscle 4 weeks after injection due to immune responses against the transgene product. We also injected AAV-CMVLacZ into skeletal muscles of mini-dystrophin-transgenic mdx mice (CVBA3'), which show ameliorated phenotypes without overt signs of muscle degeneration. AAV vector administration, however, evoked substantial immune responses in CVBA3' muscle. Importantly, AAV vector using muscle-specific MCK promoter also elicited responses in mdx muscle, but at a considerably later period. These results suggested that neo-antigens introduced by AAV vectors could evoke immune reactions in mdx muscle, since increased permeability allowed a leakage of neo-antigens from the dystrophin-deficient sarcolemma of muscle fibers. However, resident antigen-presenting cells, such as myoblasts, myotubes and regenerating immature myofibers, might also play a role in the immune response.

Volume changes in human masticatory muscles between jaw closing and opening

Most jaw muscles are complex, multipennate with multiple components. The morphologic heterogeneity of masticatory muscles reflects their functions. We hypothesized that the volume of masticatory muscles changes between jaw closing and opening, and that there is a difference in the volume change among the muscles. Magnetic resonance images of the entire head were obtained in ten normal young adult subjects before and after maximum jaw opening. The volume changes of the masseter, medial, and lateral pterygoid muscles were measured. Only slight changes were seen in the masseter and medial pterygoid muscles. The lateral pterygoid muscle, however, significantly decreased its volume during jaw opening. The results provide normative values of muscle volume in living subjects, and suggest that the volume changes differ among jaw muscles.

Pro-apoptotic effect of presenilin 2 (PS2) overexpression is associated with down-regulation of Bcl-2 in cultured neurons

Presenilin 2 (PS2) is a polytopic membrane protein that is mutated in some cases of familial Alzheimer's disease (AD). The normal functions of PS2 and its pathogenic role in AD remain unclear. We investigated the biological role of this protein in neurons, using adenovirus-mediated transduction of the PS2 gene into rat primary cortical neurons. Immunocytochemical analyses demonstrated increased PS2 immunoreactivity in most neurons infected with recombinant adenoviruses expressing PS2. Neurons infected with wild-type or mutant (N141I) PS2-expressing adenoviruses showed a significant increase in basal cell death, compared with those infected with control beta-galactosidase-expressing adenovirus. Moreover, PS2 overexpression markedly increased neuronal susceptibility to staurosporine-induced apoptosis. Mutant PS2 was more effective in enhancing apoptosis than its wild-type counterpart. Staurosporine-induced death was significantly inhibited by a specific caspase 3 inhibitor. Western analyses revealed that Bcl-2 protein expression was specifically down-regulated in neurons overexpressing PS2, which temporally corresponded to the accumulation of C- and N-terminal fragments of PS2. Additionally, expression of mutant, but not wild-type PS2, increased the production of beta-amyloid protein (Abeta) 42. These data collectively suggest that the pro-apoptotic effect of PS2 is mediated by down-regulation of Bcl-2. PS2 mutations may increase the susceptibility of neurons to apoptotic stimuli by perturbing the regulation of cell death.

Decreased sensory cortical excitability after 1 Hz rTMS over the ipsilateral primary motor cortex

OBJECTIVES

To study changes in the excitability of the sensory cortex by repetitive transcranial magnetic stimulation (rTMS) in humans.

METHODS

Somatosensory evoked potentials (SEPs) and antidromic sensory nerve action potentials (SNAPs) were elicited by right median nerve stimulation at the wrist before and after low frequency (1 Hz) rTMS over the left motor cortex, lateral premotor cortex, sensory cortex, and also after sham stimulation. The intensity of rTMS was fixed at 1.1 times the active motor threshold at the hand area of motor cortex.

RESULTS

N20 peak (N20p)-P25 and P25-N33 amplitudes were suppressed after rTMS over the motor cortex, whereas the N20 onset (N20o)-N20p and SNAP amplitudes were not affected. They recovered to the baseline about 100 min after the rTMS. rTMS over the premotor cortex or sensory cortex or sham stimulation had no suppressive effect on SEPs.

CONCLUSIONS

The reduction of N20p-P25 and P25-N33 components without any changes of N20o-N20p amplitude suggests that the suppression occurs in the sensory cortex. rTMS (1 Hz) of the motor cortex induces a long-lasting suppression of the ipsilateral sensory cortex even at an intensity as low as 1.1 times the active motor threshold, probably via cortico-cortical pathways between motor and sensory cortex.

Organ specificity of a vacuolar Ca2+-binding protein RVCaB in radish and its expression under Ca2+-deficient conditions

Radish vacuoles contain a new type of Ca2+-binding protein (RVCaB) with high capacity and low affinity for Ca2+. The protein is able to stimulate Ca2+ uptake into vacuoles, which is driven by Ca2+-ATPase and Ca2+/H+ antiporter. In the present study, we found that the level of RVCaB mRNA is high in seedling hypocotyls and mature taproots but low in young roots and mature leaves. The RVCaB protein was abundant in hypocotyls and taproots but absent in leaves. The levels of the transcript and protein of RVCaB in taproots were gradually increased during maturation. The level of RVCaB mRNA in seedling hypocotyls doubled within a few hours when the growth medium was changed from 10 mM CaCl2 to water, although the level was strongly suppressed in 100 mM CaCl2. This response of the RVCaB gene was specific to Ca2+ and did not occur with other ions including K+ and Mg2+. RVCaB functioning as a Ca2+-sequestering protein in taproot vacuoles to provide for the Ca2+ deficiency is discussed.

[Intramedullary spinal cord metastasis of lung adenocarcinoma causing Brown-Séquard Syndrome]

A 36-year-old woman admitted to our hospital because of numbness in the left limbs and weakness in the right arm, and was subsequently given a diagnosis of intramedullary spinal cord metastases from lung cancer. The patient had lung adenocarcinoma with metastases to the brain, spine and lymph nodes. Occipital craniotomy, radiation therapy and chemotherapy were performed on the lesions in the year following June 1994. In June 1995, however, she complained of numbness in the left limbs and weakness in the right arm. Compatible with her neurological manifestation, MRI demonstrated tumors in the right side of the cord at the spinal level of C3-4 and C7-Th1, both of which were of high density in T2-enhanced conditions with enhancement by gadolinium-diethylenetriamine pentaacetic acid. No invasion from spinal metastasis was detected by CT, scintigraphy or MRI. We therefore diagnosed her manifestation as Brown-Séquard syndrome caused by intramedullary spinal cord metastatic tumors of lung adenocarcinoma. In order to avoid paraplegia and dysfunction of the bladder and bowel, radiation therapy of the cord lesions with total dose of 44 Gy was performed. Her neurologic manifestation was improved, restoring her quality of life, as the tumor size estimated by MRI decreased. Four months later, however, she died of lung adenocarcinoma that developed accompanied with severe peritonitis carcinomatosa and multiple metastases.

Identification of rat cyclic nucleotide phosphodiesterase 11A (PDE11A): comparison of rat and human PDE11A splicing variants

We have isolated and characterized rat cyclic nucleotide phosphodiesterase (PDE)11A, which exhibits properties of a dual-substrate PDE, and its splice variants (RNPDE11A2, RNPDE11A3, and RNPDE11A4). The deduced amino-acid sequence of the longest form of rat PDE11A splice variant, RNPDE11A4, was 94% identical with that of the human variant (HSPDE11A4). Rat PDE11A splice variants were expressed in a tissue-specific manner. RNPDE11A4 showed unique tissue distribution distinct from HSPDE11A4, which is specifically expressed in the prostate. Rat PDE11A splice variants were expressed in COS-7 cells, and their enzymatic characteristics were compared. Although the Km values for cAMP and cGMP were similar for all of them (1.3-1.6 and 2.1-3.9 microM, respectively), the Vmax values differed significantly (RNPDE11A4 >> RNPDE11A2 > RNPDE11A3). Human PDE11A variants also displayed very similar Km values and significantly different Vmax values (HSPDE11A4 >> HSPDE11A2 > HSPDE11A3 >> HSPDE11A1). The Vmax values of HSPDE11A4 for cAMP and cGMP were at least 100 times higher than those of HSPDE11A1. These observations indicate unique characteristics of PDE11A splicing variants.

Effects of selenium deficiency on expression of selenoproteins in bovine arterial endothelial cells

Damage to the vascular endothelium by reactive oxygen species causes many cardiovascular diseases including atherosclerosis. Such damage can be prevented by selenium (Se), which is thought to exert its actions mainly through the expression of selenoproteins. Se deficiency increased the susceptibility to tert-butylhydroperoxide (t-BuOOH) and enhanced lipid peroxidation in bovine arterial endothelial cells (BAEC). We investigated the effects of Se deficiency on the expression of the selenoproteins in BAEC. 75Se metabolic labeling analysis and RT-PCR analysis revealed that BAEC expressed two glutathione peroxidase (GPx) isozymes, cytosolic GPx (cGPx) and phospholipid hydroperoxide GPx (PHGPx), three thioredoxin reductase (TrxR) isozymes, TrxR1, TrxR2 and TrxR3, and selenoprotein P (SelP). Se deficiency reduced both enzyme activity and mRNA level of cGPx, but did not affect those of PHGPx. SelP mRNA level was also reduced by Se deficiency, although the extent of reduction was much smaller than that of cGPx mRNA. We further found that TrxR activity was also decreased by Se deficiency but none of the mRNA levels of TrxR isozymes were reduced. These results indicate that vascular endothelial cells express several selenoproteins including cGPx, PHGPx, TrxR isozymes and SelP which might play important roles in the defense system against oxidative stresses and that the expressions of these selenoproteins are differently regulated by Se status.

Integration of a picture archiving and communication system with videocapture and computed radiography in a dental hospital

A method for the integration of a picture archiving and communication system (PACS) at Kyushu University Dental Hospital with radiological information (RIS) and hospital information (HIS) systems is described. CT, US and DSA from different manufacturers were integrated by videocapture and then subsequently integrated with computed radiography (CR) by means of DICOM. The approximate amount of data stored each month on optical discs is 2 GB. The system does not incorporate intra-oral radiography.

Interhemispheric interaction between the hand motor areas in patients with cortical myoclonus

OBJECTIVE

To study interhemispheric interaction between the hand motor areas of both hemispheres through the corpus callosum in myoclonus epilepsy.

SUBJECTS

Five patients with benign myoclonus epilepsy and ten age matched normal volunteers.

METHODS

We studied effects of a medially directed conditioning stimulus over the right hand motor area on responses in the right first dorsal interosseous muscle to a posteriorly directed test stimulus over the left hand motor area.

RESULTS

In normal subjects, inhibition was evoked at interstimulus intervals (ISIs) of 8-20ms (late inhibition). In contrast, facilitation occurred in patients at ISIs of 4-6ms (early facilitation) with no late inhibition.

CONCLUSIONS

The lack of late inhibition in the patients is consistent with the idea that cortical inhibitory interneurones are affected in myoclonus epilepsy. We propose that this releases interhemispheric facilitation from powerful surround inhibition. The consequence is a predominant early facilitation between the hemispheres in patients with myoclonus epilepsy.

Overexpression of presenilin-2 enhances apoptotic death of cultured cortical neurons

Presenilin-2 (PS2) is a gene of unknown function linked with some forms of familial Alzheimer's disease. To investigate the biological role of PS2 in neurons, we overexpressed PS2 in primary cortical neurons using recombinant adenoviral vectors. Western blot and immunohistochemical analyses showed enhanced expression of PS2 proteins in infected neurons after infection of recombinant adenoviruses containing the human wild-type or mutant PS2 gene. Neuronal survival was decreased by approximately 30% in cultures infected with adenovirus expressing either wild-type or mutant PS2, as compared with those infected with adenovirus expressing the LacZ gene. Fragmented nuclei were frequently observed in dying neurons. These data suggest that apoptotic death of cultured cortical neurons is enhanced by PS2 overexpression.

Genomic organization of the human phosphodiesterase PDE11A gene. Evolutionary relatedness with other PDEs containing GAF domains

PDE11A is a dual-substrate, cAMP and cGMP, cyclic nucleotide phosphodiesterase (PDE). Presently four unique variants carrying distinct GAF sequences in the N-terminal region have been identified. While human PDE11A3 and PDE11A4 are known to be specifically expressed in testis and prostate, respectively, PDE11A1 was mainly detected in skeletal muscle. The human PDE11A gene was investigated and revealed to span > 300 kb, contain 23 exons and be mapped on chromosome 2q31. The transcription start sites of PDE11A1, PDE11A3 and PDE11A4 were determined, and the promoter sequences were revealed. Although 5' flanking genomic regions of PDE11A1 and PDE11A3 had a consensus TATA motif, that of PDE11A4 was a TATA-less but contained CCAAT box and Sp1-binding sequence. Interestingly, we found that the exon 2 sequence for N-terminal region of PDE11A3 encoded an N-terminal sequence of the cytochrome c pseudogene in an alternate reading frame, and that C-terminal region of the cytochrome c pseudogene in intron 2 was disrupted by the insertion of Alu repetitive sequence. Furthermore, we examined the exon-intron organization of the PDE2A gene and compared the exon organization among GAF-PDE family. The exon organization of the PDE11A catalytic domain was very similar to those of PDE5A and PDE6B. However, other GAF-PDEs, PDE2A and PDE10A, displayed different exon organization from PDE11A although these three PDEs are similar in their amino-acid sequences to each other. The findings suggested that PDE11A has a common ancestral gene with PDE5A and PDE6s, whereas PDE2A and PDE10A are generated separately from these three GAF-PDEs.

Purification, properties, and molecular cloning of a novel Ca(2+)-binding protein in radish vacuoles

To understand the roles of plant vacuoles, we have purified and characterized a major soluble protein from vacuoles of radish (Raphanus sativus cv Tokinashi-daikon) taproots. The results showed that it is a novel radish vacuole Ca(2+)-binding protein (RVCaB). RVCaB was released from the vacuolar membrane fraction by sonication, and purified by ion exchange and gel filtration column chromatography. RVCaB is an acidic protein and migrated on sodium dodecyl sulfate-polyacrylamide gel with an apparent molecular mass of 43 kD. The Ca(2+)-binding activity was confirmed by the (45)Ca(2+)-overlay assay. RVCaB was localized in the lumen, as the protein was recovered in intact vacuoles prepared from protoplasts and was resistant to trypsin digestion. Plant vacuoles store Ca(2+) using two active Ca(2+) uptake systems, namely Ca(2+)-ATPase and Ca(2+)/H(+) antiporter. Vacuolar membrane vesicles containing RVCaB accumulated more Ca(2+) than sonicated vesicles depleted of the protein at a wide range of Ca(2+) concentrations. A cDNA (RVCaB) encoding a 248-amino acid polypeptide was cloned. Its deduced sequence was identical to amino acid sequences obtained from several peptide fragments of the purified RVCaB. The deduced sequence is not homologous to that of other Ca(2+)-binding proteins such as calreticulin. RVCaB has a repetitive unique acidic motif, but not the EF-hand motif. The recombinant RVCaB expressed in Escherichia coli-bound Ca(2+) as evidenced by staining with Stains-all and migrated with an apparent molecular mass of 44 kD. These results suggest that RVCaB is a new type Ca(2+)-binding protein with high capacity and low affinity for Ca(2+) and that the protein could function as a Ca(2+)-buffer and/or Ca(2+)-sequestering protein in the vacuole.

Characterization and effects of methyl-2- (4-aminophenyl)-1, 2-dihydro-1-oxo-7- (2-pyridinylmethoxy)-4-(3,4, 5-trimethoxyphenyl)-3-isoquinoline carboxylate sulfate (T-1032), a novel potent inhibitor of cGMP-binding cGMP-specific phosphodiesterase (PDE5)

An isoquinolone derivative, methyl-2-(4-aminophenyl)-1, 2-dihydro-1-oxo-7-(2-pyridinylmethoxy)-4-(3,4, 5-trimethoxyphenyl)-3-isoquinoline carboxylate sulfate (T-1032), was found to be a novel potent inhibitor of cyclic GMP (cGMP)-binding cGMP-specific phosphodiesterase (PDE5). We investigated the inhibitory effects of T-1032 on six PDE isozymes isolated from canine tissues. T-1032 specifically inhibited the hydrolysis of cGMP by PDE5 partially purified from canine lung, at a low concentration (IC(50) = 1.0 nM, K(i) = 1.2 nM), in a competitive manner. In contrast, the IC(50) values of T-1032 for PDE1, PDE2, PDE3, and PDE4 were more than 1 microM. T-1032 also inhibited PDE6 from canine retina with an IC(50) of 28 nM, which is of the same order of magnitude as the IC(50) of sildenafil. cGMP hydrolytic activities of two alternative splice variants of canine PDE5 expressed in COS-7 cells were inhibited by this compound to a similar extent. T-1032 increased the intracellular concentration of cGMP in cultured rat vascular smooth muscle cells in the presence and absence of C-type natriuretic peptide, an activator of membrane-bound guanylate cyclase, whereas the compound did not change cyclic AMP levels. These data indicated that T-1032, which belongs to a new structural class of PDE5 inhibitors, is a potent and selective PDE5 inhibitor. This compound may be useful in pharmacological studies to examine the role of a cGMP/PDE5 pathway in tissues.

Isolation and characterization of two novel phosphodiesterase PDE11A variants showing unique structure and tissue-specific expression

cDNAs encoding a novel phosphodiesterase, phosphodiesterase 11A (PDE11A), were isolated by a combination of reverse transcriptase-polymerase chain reaction using degenerate oligonucleotide primers and rapid amplification of cDNA ends. Their catalytic domain was identical to that of PDE11A1 (490 amino acids) reported during the course of this study. However, the cDNAs we isolated had N termini distinct from PDE11A1, indicating two novel N-terminal variants of PDE11A. PDE11A3 cDNA encoded a 684-amino acid protein including one complete and one incomplete GAF domain in the N-terminal region. PDE11A4 was composed of 934 amino acids including two complete GAF domains and shared 630 C-terminal amino acids with PDE11A3 but had a distinct N terminus containing the putative phosphorylation sites for cAMP- and cGMP-dependent protein kinases. PDE11A3 transcripts were specifically expressed in testis, whereas PDE11A4 transcripts were particularly abundant in prostate. Recombinant PDE11A4 expressed in COS-7 cells hydrolyzed cAMP and cGMP with K(m) values of 3.0 and 1.4 microm, respectively, and the V(max) value with cAMP was almost twice that with cGMP. Although PDE11A3 showed the same K(m) values as PDE11A4, the relative V(max) values of PDE11A3 were approximately one-sixth of those of PDE11A4. PDE11A4, but not PDE11A3, was phosphorylated by both cAMP- and cGMP-dependent protein kinases in vitro. Thus, the PDE11A gene undergoes tissue-specific alternative splicing that generates structurally and functionally distinct gene products.

The human phosphodiesterase PDE10A gene genomic organization and evolutionary relatedness with other PDEs containing GAF domains

PDE10A is a cyclic nucleotide phosphodiesterase (PDE) exhibiting properties of a cAMP PDE and a cAMP-inhibited cGMP PDE. The transcripts are specifically expressed in the striatum. The human gene encoding PDE10A was cloned and investigated. The PDE10A gene spanned > 200 kb and contained 24 exons. The exon-intron organization of PDE10A was different from those of PDE5A and PDE6B, although these three PDEs include two GAF domains and have similar amino-acid sequences. The promoter sequence of PDE10A was highly GC-rich and did not contain a TATA motif and a CAAT box, suggesting it is a housekeeping gene. In Caenorhabditis elegans, the C32E12.2 gene encoding a probable PDE that is 48% identical to the human PDE10A protein showed similar exon organization to PDE10A but not PDE5A and PDE6B. This, together with the phylogenic tree analysis, suggested that the ancestral gene for PDE10A existed in a lower organism such as C. elegans.

Tumor recurrence criteria for postoperative contrast-enhanced computed tomography after surgical treatment of oral cancer and flap repair

OBJECTIVE

To characterize the computed tomography (CT) findings that distinguish cancer recurrence from postoperative changes that mimic such recurrence.

STUDY DESIGN

We evaluated a total of 72 CT scans from 32 patients who had undergone surgery with either pectoralis major myocutaneous flap or forearm flap. The observers evaluated the presence and pattern of enhancement, the presence of low density areas, and changes in the adipose tissue of the flap.

RESULTS

A persistent zone of high attenuation over 6 months suggested the high possibility of recurrence. However, an enhancement within 6 months occurred both with the recurrent tumor and with postoperative tissue. In the patients with recurrence (n = 12), the enhanced areas were focal (n = 8) or diffuse (n = 4). Focal-type recurrence often occurred at the posterior margin. The presence of low-density areas and changes in the adipose tissue in the flap are also helpful for detecting recurrence.

CONCLUSIONS

The combination of several features seen on CT images can be useful in differentiating tumor recurrence from postoperative tissue changes.

Closed-Wedge osteotomy for osteochondritis dissecans of the capitellum. A 7- to 12-year follow-up

This article details a 7- to 12-year follow-up of seven young male baseball players with osteochondritis dissecans of the capitellum that we treated using closed-wedge osteotomy. This procedure was established by Yoshizu in 1986 for the treatment of "Little League elbow." The bone of the capitellum was revascularized and remodeled within 6 months in all seven patients. Six of the patients were able to return to full athletic activity and continued to play baseball. Radiographic assessment during the follow-up study revealed minimal osteoarthritic change and suggests that the treatment is useful for such an injury.

Computed tomography and ultrasonography of metastatic cervical lymph nodes in oral squamous cell carcinoma

OBJECTIVES

To define criteria for CT and US in differentiating cervical lymph node metastases in oral squamous cell carcinoma (SCC).

MATERIALS AND METHODS

CT and/or US of 230 metastatic lymph nodes and 228 benign lymph nodes in 147 patients with oral SCC were retrospectively evaluated. The CT and US findings of each lymph node were compared with the histopathological findings. A metastasis was defined on CT as a lymph node with rim or heterogeneous enhancement, or measuring 10 mm or more in the short axis, regardless of enhancement pattern, and on US as having definite internal echoes, regardless of size, or without definite internal or hilar echoes, but measuring 10 mm or more in the short axis. A lymph node with hilar echoes or a ratio of the long to short axis (L/S ratio) of 3.5 or more was considered benign. A lymph node failing to comform to any of these categories was termed questionable.

RESULTS

The positive predictive value (PPV) for CT was 90.8% and the negative predictive value (NPV) was 70.4%. However, 65.7% of all lymph nodes could not be classified as either metastastic or benign. PPV for US was 96.5% and NPV was 88.1%. 25.5% of all lymph nodes could not be classified as either metastatic or benign.

CONCLUSIONS

Despite limitations in detecting metastases, by including a third category 'questionable' our criteria appear clinically more useful than other current methods based on two groups only.

Sonography for the detection of cervical lymph node metastases among patients with tongue cancer: criteria for early detection and assessment of follow-up examination intervals

BACKGROUND AND PURPOSE

Because the presence of cervical metastasis is one of the factors influencing the outcome of patients with carcinoma of the head and neck, its early detection is potentially very important. The purpose of this study was to evaluate the characteristic changes of cervical metastasis revealed by sonography during follow-up and to assess an adequate interval for follow-up sonography of the neck among patients with tongue cancer.

METHODS

Forty-three of 44 consecutive patients with squamous cell carcinoma of the tongue, who had undergone interstitial brachytherapy, were examined with sonography of the neck during the posttherapeutic follow-up period.

RESULTS

Seventeen cervical lymph node metastases were found in 12 of 43 patients during follow-up. Of these 17 cervical metastases, 16 (94.1%) were accurately diagnosed and one (5.9%) was misdiagnosed as nonmetastatic based on sonographic findings. Sonography of the neck performed in seven patients at an interval of less than 1 month since the last follow-up imaging showed 9 (90.0%) of 10 metastases increased by up to 2 mm in short-axis diameter. Five patients who were followed up at an interval of more than 1 month since the last follow-up imaging had seven metastases increase by 3 to 8 mm in short-axis diameter or a change of echogenicity in the internal structure of lymph nodes or both. Pathologic examinations showed extranodal spread in 3 (42.9%) of these 7 metastases.

CONCLUSION

Changes both in size and internal echogenicity can occur as quickly as 2 to 4 weeks between sonographic examinations. Therefore, in high-risk patients, or in those with suspicious sonographic findings, short-interval follow-up sonographic examinations are recommended at least during the first posttherapeutic year. Our findings suggest that follow-up sonography of the neck should be performed monthly, at least during the first posttherapeutic year.

Identification of human PDE7B, a cAMP-specific phosphodiesterase

We isolated a human cAMP-specific phosphodiesterase (PDE7B) cDNA from human caudate nucleus. The human PDE7B was composed of 450 amino acid residues with a molecular mass of 51,835 Da. The deduced amino acid sequence of human PDE7B was 64.1% identical to that of human PDE7A (67.1% identity in the catalytic region). Northern blot analysis demonstrated that PDE7B transcripts were abundantly expressed in the putamen, caudate nucleus, and heart followed by skeletal muscle, pancreas, and occipital pole. Recombinant PDE7B expressed in transfected COS-7 cells had a low cAMP K(m) value of 0. 13 microM, which is similar to the K(m) value of recombinant human PDE7A expressed in transfected COS-7 cells. Interestingly, the relative V(max) value of recombinant PDE7B was half to one-third of recombinant PDE7A. The PDE7B activity was inhibited by dipyridamole and SCH51866, with IC(50) values of 1.1 microM and 1.5 microM, respectively. Thus, the PDE7B exhibited unique tissue distribution in humans and kinetic profiles. Human PDE7B showed the lowest K(m) values compared to the other cAMP-hydrolyzing PDEs which have been reported to be expressed in the brain. Therefore, human PDE7B may be involved in the control of cAMP-mediated neural activity and cAMP metabolism in the brain.

A study of the association between the prognosis of carcinoma of the mandibular gingiva and the pattern of bone destruction on computed tomography

OBJECTIVE

To clarify whether the pattern of bone destruction seen on CT is more closely associated with the outcome of carcinoma of the mandibular gingiva than that derived from panoramic radiographs (PR).

METHOD

Axial bone window CT scans and PR of 62 patients with carcinoma of the mandibular gingiva were evaluated retrospectively by two oral radiologists for the pattern of bone destruction. Patterns were classified into the three types: erosive, invasive and mixed. The relationship between these patterns with each imaging modality and cumulative recurrence rate, cumulative metastasis rate and cumulative survival rate, calculated by the Kaplan-Meier method, were statistically analysed by the log rank test.

RESULTS

The pattern of bone destruction derived from CT was closely associated with the cumulative metastasis rate (P < 0.05), the cumulative recurrence rate and the cumulative survival rate. In contrast, the pattern of bone destruction based on the PR was not associated with the cumulative metastasis rate (P = 0.43), the cumulative recurrence rate (P = 0.44), or the cumulative survival rate (P = 0.5).

CONCLUSION

The prognosis of patients with carcinoma of the mandibular gingiva is more closely related to a classification derived from the pattern of bone destruction on CT rather than PR. However, the number of subjects investigated in this study was not large enough to confirm our conclusions statistically. Further studies by other investigators are therefore needed.

A new, simple method of making a spacer in interstitial brachytherapy for mobile tongue cancer

OBJECTIVES

This article demonstrates a new method of making a spacer that increases the distance between the mandible and implanted radioactive sources in interstitial brachytherapy for patients with mobile tongue cancer.

STUDY DESIGN

Fifty-three patients with mobile tongue cancer underwent interstitial brachytherapy with spacers made by this new technique.

RESULTS

Our spacer is not difficult to create or to use. The spacer was made from a plastic splint by using thermoforming techniques and quick self-curing resin, which did not need waxing, wiring, or casting. The surface of the spacer, which comes in contact with the tongue, is smooth because it is covered with tissue-conditioning material. There were no complaints of pain from the patients. Osteoradionecrosis of the mandible developed in only 1 (1.9%) of these patients.

CONCLUSIONS

This spacer is simple to make and prevented osteoradionecrosis.

Immune response to adenovirus-delivered antigens upregulates utrophin and results in mitigation of muscle pathology in mdx mice

The upregulation of endogenous utrophin in skeletal muscle may lead to a new approach to the treatment of Duchenne muscular dystrophy (DMD). We found that injection of an E1, E3-deleted adenovirus vector expressing beta-galactosidase (beta-Gal) or green fluorescent protein (GFP) into the skeletal muscle of neonatal dystrophin-deficient mdx mice alleviated dystrophic pathology. In the adenovirus-infected muscles, an evaluation of sarcolemma stability showed low permeability and immunohistochemistry revealed utrophin upregulation at the extrasynaptic sarcolemma of mature muscle fibers. This utrophin upregulation was concomitant with endomysial cellular infiltration from a host immune reaction. There was no evidence of active muscle regeneration. In normal C57BL/10 mice, utrophin was also upregulated in adenovirus-injected skeletal muscles, where upregulated utrophin often coexisted with dystrophin. FK506 and anti-CD4 antibody administration decreased utrophin expression in adenovirus-injected mdx muscles and prevented the dystrophic phenotype from being mitigated, suggesting that an immune reaction is involved in utrophin upregulation. This is the first report demonstrating the improvement of the dystrophic phenotype as a result of the acquired overexpression of endogenous utrophin. Our findings provide an important clue to understanding the mechanism of utrophin expression and the development of an effective treatment for DMD.

Binding and phosphorylation of a novel male germ cell-specific cGMP-dependent protein kinase-anchoring protein by cGMP-dependent protein kinase Ialpha

cGMP-dependent protein kinase (cGK) is a major cellular receptor of cGMP and plays important roles in cGMP-dependent signal transduction pathways. To isolate the components of the cGMP/cGK signaling pathway such as substrates and regulatory proteins of cGK, we employed the yeast two-hybrid system using cGK-Ialpha as a bait and isolated a novel male germ cell-specific 42-kDa protein, GKAP42 (42-kDa cGMP-dependent protein kinase anchoring protein). Although the N-terminal region (amino acids 1-66) of cGK-Ialpha is sufficient for the association with GKAP42, GKAP42 could not interact with cGK-Ibeta, cGK-II, or cAMP-dependent protein kinase. GKAP42 mRNA is specifically expressed in testis, where it is restricted to the spermatocytes and early round spermatids. Endogenous cGK-I is co-immunoprecipitated with anti-GKAP42 antibody from mouse testis tissue, suggesting that cGK-I physiologically interacts with GKAP42. Immunocytochemical observations revealed that GKAP42 is localized to the Golgi complex and that cGK-Ialpha is co-localized to the Golgi complex when coexpressed with GKAP42. Although both cGK-Ialpha and -Ibeta, but not cAMP-dependent protein kinase, phosphorylated GKAP42 in vitro, GKAP42 was a good substrate only for cGK-Ialpha in intact cells, suggesting that the association with kinase protein is required for the phosphorylation in vivo. Finally, we demonstrated that the kinase-deficient mutant of cGK-Ialpha stably associates with GKAP42 and that binding of cGMP to cGK-Ialpha facilitates their release from GKAP42. These findings suggest that GKAP42 functions as an anchoring protein for cGK-Ialpha and that cGK-Ialpha may participate in germ cell development through phosphorylation of Golgi-associated proteins such as GKAP42.

Identification of a conserved residue responsible for the autoinhibition of cGMP-dependent protein kinase Ialpha and beta

We isolated a constitutively active form of cGMP-dependent protein kinase Ialpha (cGK Ialpha) by PCR-driven random mutagenesis. The replacement of Ile-63 by Thr in the autoinhibitory domain results in the enhancement of autophosphorylation and the basal kinase activity in the absence of cGMP. The hydrophobicity at position 63 is essential for the inactive state of cGK Ialpha, and Ile-78 of cGK Ibeta is also required for the autoinhibitory property. Furthermore, cGK Ialpha (Ile-63-Thr) is constitutively active in vivo. These findings suggest that a conserved residue in the autoinhibitory domain was involved in the autoinhibition of both cGK Is.