Endothelial ROBO4 suppresses PTGS2/COX-2 expression and inflammatory diseases

Accumulating evidence suggests that endothelial cells can be useful therapeutic targets. One of the potential targets is an endothelial cell-specific protein, Roundabout4 (ROBO4). ROBO4 has been shown to ameliorate multiple diseases in mice, including infectious diseases and sepsis. However, its mechanisms are not fully understood. In this study, using RNA-seq analysis, we found that ROBO4 downregulates prostaglandin-endoperoxide synthase 2 (PTGS2), which encodes cyclooxygenase-2. Mechanistic analysis reveals that ROBO4 interacts with IQ motif-containing GTPase-activating protein 1 (IQGAP1) and TNF receptor-associated factor 7 (TRAF7), a ubiquitin E3 ligase. In this complex, ROBO4 enhances IQGAP1 ubiquitination through TRAF7, inhibits prolonged RAC1 activation, and decreases PTGS2 expression in inflammatory endothelial cells. In addition, Robo4-deficiency in mice exacerbates PTGS2-associated inflammatory diseases, including arthritis, edema, and pain. Thus, we reveal the molecular mechanism by which ROBO4 suppresses the inflammatory response and vascular hyperpermeability, highlighting its potential as a promising therapeutic target for inflammatory diseases.

Heterogeneity of endothelial VE-PTP downstream polarization, Tie2 activation, junctional claudin-5, and permeability in the aorta and vena cava

Endothelial cells of mammalian blood vessels have multiple levels of heterogeneity along the vascular tree and among different organs. Further heterogeneity results from blood flow turbulence and variations in shear stress. In the aorta, vascular endothelial protein tyrosine phosphatase (VE-PTP), which dephosphorylates tyrosine kinase receptor Tie2 in the plasma membrane, undergoes downstream polarization and endocytosis in endothelial cells exposed to laminar flow and high shear stress. VE-PTP sequestration promotes Tie2 phosphorylation at tyrosine992 and endothelial barrier tightening. The present study characterized the heterogeneity of VE-PTP polarization, Tie2-pY992 and total Tie2, and claudin-5 in anatomically defined regions of endothelial cells in the mouse descending thoracic aorta, where laminar flow is variable and IgG extravasation is patchy. We discovered that VE-PTP and Tie2-pY992 had mosaic patterns, unlike the uniform distribution of total Tie2. Claudin-5 at tight junctions also had a mosaic pattern, whereas VE-cadherin at adherens junctions bordered all endothelial cells. Importantly, the amounts of Tie2-pY992 and claudin-5 in aortic endothelial cells correlated with downstream polarization of VE-PTP. VE-PTP and Tie2-pY992 also had mosaic patterns in the vena cava, but claudin-5 was nearly absent and extravasated IgG was ubiquitous. Correlation of Tie2-pY992 and claudin-5 with VE-PTP polarization supports their collective interaction in the regulation of endothelial barrier function in the aorta, yet differences between the aorta and vena cava indicate additional flow-related determinants of permeability. Together, the results highlight new levels of endothelial cell functional mosaicism in the aorta and vena cava, where blood flow dynamics are well known to be heterogeneous.

Shear stress control of vascular leaks and atheromas through Tie2 activation by VE-PTP sequestration

Vascular endothelial protein tyrosine phosphatase (VE-PTP) influences endothelial barrier function by regulating the activation of tyrosine kinase receptor Tie2. We determined whether this action is linked to the development of atherosclerosis by examining the influence of arterial shear stress on VE-PTP, Tie2 activation, plasma leakage, and atherogenesis. We found that exposure to high average shear stress led to downstream polarization and endocytosis of VE-PTP accompanied by Tie2 activation at cell junctions. In aortic regions with disturbed flow, VE-PTP was not redistributed away from Tie2. Endothelial cells exposed to high shear stress had greater Tie2 activation and less macromolecular permeability than regions with disturbed flow. Deleting endothelial VE-PTP in VE-PTPiECKO mice increased Tie2 activation and reduced plasma leakage in atheroprone regions. ApoE-/- mice bred with VE-PTPiECKO mice had less plasma leakage and fewer atheromas on a high-fat diet. Pharmacologic inhibition of VE-PTP by AKB-9785 had similar anti-atherogenic effects. Together, the findings identify VE-PTP as a novel target for suppression of atherosclerosis.

SARS-CoV-2 disrupts respiratory vascular barriers by suppressing Claudin-5 expression

In the initial process of coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects respiratory epithelial cells and then transfers to other organs the blood vessels. It is believed that SARS-CoV-2 can pass the vascular wall by altering the endothelial barrier using an unknown mechanism. In this study, we investigated the effect of SARS-CoV-2 on the endothelial barrier using an airway-on-a-chip that mimics respiratory organs and found that SARS-CoV-2 produced from infected epithelial cells disrupts the barrier by decreasing Claudin-5 (CLDN5), a tight junction protein, and disrupting vascular endothelial cadherin-mediated adherens junctions. Consistently, the gene and protein expression levels of CLDN5 in the lungs of a patient with COVID-19 were decreased. CLDN5 overexpression or Fluvastatin treatment rescued the SARS-CoV-2-induced respiratory endothelial barrier disruption. We concluded that the down-regulation of CLDN5 expression is a pivotal mechanism for SARS-CoV-2-induced endothelial barrier disruption in respiratory organs and that inducing CLDN5 expression is a therapeutic strategy against COVID-19.

Vascular Leakage Prevention by Roundabout 4 under Pathological Conditions

Vascular permeability is regulated mainly by the endothelial barrier and controls vascular homeostasis, proper vessel development, and immune cell trafficking. Several molecules are involved in regulating endothelial barrier function. Roundabout 4 (Robo4) is a single-pass transmembrane protein that is specifically expressed in vascular endothelial cells. Robo4 is an important regulator of vascular leakage and angiogenesis, especially under pathological conditions. The role of Robo4 in preventing vascular leakage has been studied in various disease models, including animal models of retinopathy, tumors, diabetes, and endotoxemia. The involvement of Robo4 in vascular endothelial growth factor and inflammation-mediated signaling pathways has been well studied, and recent evidence suggests that Robo4 modulates endothelial barrier function via distinct mechanisms. In this review, we discuss the role of Robo4 in endothelial barrier function and the underlying molecular mechanisms.

Safety and efficacy of an anti-claudin-5 monoclonal antibody to increase blood-brain barrier permeability for drug delivery to the brain in a non-human primate

Claudin-5 (CLDN-5) is an essential component of the tight junction seal in the blood-brain barrier. Previously, we showed that CLDN-5 modulation in vitro via an anti-CLDN-5 monoclonal antibody (mAb) may be useful for increasing the permeability of the blood-brain barrier for drug delivery to the brain. Based on these findings, here we examined the safety and efficacy of the anti-CLDN-5 mAb in a non-human primate. Cynomolgus monkeys were intravenously administered the anti-CLDN-5 mAb followed by fluorescein dye (376 Da), and the concentrations of the dye in the cerebrospinal fluid was examined. When the mAb was administered at 3.0 mg/kg, the concentration of dye in the cerebrospinal fluid was increased, and no behavioral changes or changes in plasma biomarkers for inflammation or liver or kidney injury were observed. However, a monkey that received the mAb at 6 mg/kg experienced convulsions, and subsequent histopathological examination of this animal revealed vasodilation in the liver, lung, and kidney; hemorrhage in the lung; and edema in the brain. Together, our data indicate that CLDN-5 might be a potential target for enhancing drug delivery to the brain, but also that the therapeutic window of the anti-CLDN-5 mAb may be narrow for separating efficacy and toxicity.

HDAC inhibitor, MS-275, increases vascular permeability by suppressing Robo4 expression in endothelial cells

Roundabout guidance receptor 4 (Robo4) is an endothelial-specific membrane protein that suppresses pathological angiogenesis and vascular hyperpermeability by stabilizing endothelial cells. Robo4 suppresses severe systemic inflammation induced by pathogens and endotoxins and inhibits tumor growth and metastasis, therefore serving as a potential therapeutic target. Although the regulation of Robo4 expression through transcription factors and epigenetic mechanisms has been studied, the role of histone deacetylases (HDACs) has not been explored. In the present study, we investigated the involvement of HDACs in the regulation of Robo4 expression. An HDAC inhibitor, MS-275, which inhibits HDAC1, HDAC2, and HDAC3, was found to suppress Robo4 expression in endothelial cells. Small interfering RNA (siRNA)-mediated knockdown of HDAC3, but not of HDAC1 and 2, also decreased its expression level. MS-275 downregulated the expression of the transcription factor complex GABP, in addition to suppressing Robo4 promoter activity. GABP expression was also downregulated by the siRNA against HDAC3. MS-275 decreased the transendothelial electrical resistance of a monolayer of mouse endothelial cells and increased the rate of leakage of Evans blue dye in the mouse lungs. In addition, MS-275 accelerated cell migration through the endothelial cell monolayer and augmented cell extravasation in the mouse lungs. Taken together, we demonstrated that MS-275 suppresses Robo4 expression by inhibiting HDAC3 in endothelial cells and enhances endothelial and vascular permeability. Thus, we demonstrated a novel mechanism regulating Robo4 expression and vascular permeability, which is anticipated to contribute to future therapies for infectious and inflammatory diseases.

The Robo4-TRAF7 complex suppresses endothelial hyperpermeability in inflammation

Roundabout guidance receptor 4 (Robo4) is an endothelial cell-specific receptor that stabilizes the vasculature in pathological angiogenesis. Although Robo4 has been shown to suppress vascular hyperpermeability induced by vascular endothelial growth factor (VEGF) in angiogenesis, the role of Robo4 in inflammation is poorly understood. In this study, we investigated the role of Robo4 in vascular hyperpermeability during inflammation. Endotoxemia models using Robo4 ^-/- mice showed increased mortality and vascular leakage. In endothelial cells, Robo4 suppressed tumor necrosis factor α (TNFα)-induced hyperpermeability by stabilizing VE-cadherin at cell junctions, and deletion assays revealed that the C-terminus of Robo4 was involved in this suppression. Through binding and localization assays, we demonstrated that in endothelial cells, Robo4 binds to TNF receptor-associated factor 7 (TRAF7) through interaction with the C-terminus of Robo4. Gain- and loss-of-function studies of TRAF7 with or without Robo4 expression showed that TRAF7 is required for Robo4-mediated suppression of hyperpermeability. Taken together, our results demonstrate that the Robo4-TRAF7 complex is a novel negative regulator of inflammatory hyperpermeability. We propose this complex as a potential future target for protection against inflammatory diseases.

ETV2-TET1/TET2 Complexes Induce Endothelial Cell-Specific Robo4 Expression via Promoter Demethylation

Although transcription factors regulating endothelial cell (EC)-specific gene expression have been identified, it is not known how those factors induce EC-specificity. We previously reported that DNA hypomethylation of the proximal promoter elicits EC-specific expression of Roundabout4 (Robo4). However, the mechanisms establishing EC-specific hypomethylation of the Robo4 promoter remain unknown. In this study, we demonstrated that the hypermethylated Robo4 proximal promoter is demethylated as human iPS cells differentiate into endothelial cells. Reporter assays demonstrated that ETV2, an ETS family transcription factor, bound to ETS motifs in the proximal promoter and activated Robo4 expression. Immunoprecipitation demonstrated direct interaction between ETV2 and methylcytosine-converting enzymes TET1 and TET2. Adenoviral expression of ETV2-TET1/TET2 complexes demethylated the Robo4 promoter and induced Robo4 expression in non-ECs. In summary, we propose a novel regulatory model of EC-specific gene expression via promoter demethylation induced by ETV2-TET1/TET2 complexes during endothelial differentiation.

Endothelial cell-specific expression of roundabout 4 is regulated by differential DNA methylation of the proximal promoter

OBJECTIVE

The molecular basis of endothelial cell (EC)-specific gene expression is poorly understood. Roundabout 4 (Robo4) is expressed exclusively in ECs. We previously reported that the 3-kb 5'-flanking region of the human Robo4 gene contains information for lineage-specific expression in the ECs. Our studies implicated a critical role for GA-binding protein and specificity protein 1 (SP1) in mediating overall expression levels. However, these transcription factors are also expressed in non-ECs. In this study, we tested the hypothesis that epigenetic mechanisms contribute to EC-specific Robo4 gene expression.

METHODS AND RESULTS

Bisulfite sequencing analysis indicated that the proximal promoter of Robo4 is methylated in non-ECs but not in ECs. Treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine increased Robo4 gene expression in non-ECs but not in ECs. Proximal promoter methylation significantly decreased the promoter activity in ECs. Electrophoretic mobility shift assays showed that DNA methylation of the proximal promoter inhibited SP1 binding to the -42 SP1 site. In DNase hypersensitivity assays, chromatin condensation of the Robo4 promoter was observed in some but not all nonexpressing cell types. In Hprt (hypoxanthine phosphoribosyltransferase)-targeted mice, a 0.3-kb proximal promoter directed cell-type-specific expression in the endothelium. Bisulfite sequencing analysis using embryonic stem cell-derived mesodermal cells and ECs indicated that the EC-specific methylation pattern of the promoter is determined by demethylation during differentiation and that binding of GA-binding protein and SP1 to the proximal promoter is not essential for demethylation.

CONCLUSIONS

The EC-specific DNA methylation pattern of the Robo4 proximal promoter is determined during cell differentiation and contributes to regulation of EC-specific Robo4 gene expression.

Double-balloon endoscopy versus magnet-imaging enhanced colonoscopy for difficult colonoscopies, a randomized study

BACKGROUND AND STUDY AIMS

Studies have estimated that failure of cecal intubation occurs with conventional colonoscopy in up to 10 % of cases. Double-balloon endoscopy (DBE) systems, magnetic endoscope imaging (MEI), and transparent cap have been shown to improve success rates for colonoscopy. This study evaluated the utility of DBE for complete examination of the colon compared with MEI plus cap (MEI-Cap) after incomplete or technically difficult colonoscopy in a randomized comparative manner.

PATIENTS AND METHODS

A total of 94 patients with incomplete or technically difficult colonoscopy were randomly assigned to receive either DBE (n = 47) or colonoscopy with MEI-Cap (n = 47). The primary end point was cecal intubation rate within 30 minutes. Secondary end points included intubation time, pain score using a visual analog scale, abdominal pressure attempts, doses of sedative medication, and changes in patient position during colonoscopy.

RESULTS

Patient characteristics were comparable in both groups. Cecal intubation rate within 30 minutes was significantly higher for DBE (45 /47, 95.7 %) than for MEI-Cap (34 /47, 72.3 %) (P = 0.0049). Mean time to reach the cecum was significantly lower in the DBE group (13.0 ± 5.3 minutes) than in the MEI-Cap group (16.4 ± 4.8 minutes; P = 0.0003). No complications were encountered in either group.  

CONCLUSION

DBE is more useful for complete examination of the colon than MEI-Cap in patients with incomplete or technically difficult colonoscopy.

Changes in biochemical parameters after anterior cruciate ligament injury

We studied the biochemical characteristics of human knees with deficient anterior cruciate ligaments (ACL) and analysed their relationship to the time after ligamentous injury. Thirty-two patients with isolated ACL-injured knees and six healthy volunteers were enrolled. Synovial fluid samples were centrifuged after aspiration during arthroscopic examination, and aliquots of supernatant were frozen and stored at -80 degrees C. The samples were analysed for interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, IL-6, matrix metalloproteinase (MMP)-3, and tissue inhibitor of metalloproteinase (TIMP)-1 using commercially available sandwich enzyme-linked immunosorbent assay. In fluid from ACL-injured knees, the average concentrations of IL-6, MMP-3 and TIMP-1 were highly elevated in comparison with normal controls. There was a statistically significant correlation between the concentrations of MMP-3 and IL-6. The IL-6 and TIMP-1 concentrations were interrelated. The concentration of MMP-3 remained high, independent of the duration since the injury, whereas the TIMP-1 and IL-6 levels decreased. The results suggest that the timing of the treatment of an ACL-injured knee might be of importance.

Varus inclination of the distal femur and high tibial osteotomy

We have analysed retrospectively the relationship between the axial parameters of alignment of the lower limb and the recurrence of varus deformity after high tibial osteotomy. We studied 29 patients (37 knees) with a mean age at surgery of 66 years. The mean follow-up was for 7.4 years (5 to 10.5). Recurrence of varus deformity was defined as an increase in the femorotibial angle of 3° or more, compared with that obtained six months after the operation. There were four patients (four knees) with recurrence of varus deformity. They had a greater varus inclination of the distal femur than those without varus recurrence.

An association between varus inclination of the distal femur and horizontal obliquity of the joint surface was observed. Excessive obliquity prevents the shift of weight-bearing to the lateral compartment, and may cause a recurrence of varus deformity after high tibial osteotomy.

Varus inclination of the distal femur and high tibial osteotomy

We have analysed retrospectively the relationship between the axial parameters of alignment of the lower limb and the recurrence of varus deformity after high tibial osteotomy. We studied 29 patients (37 knees) with a mean age at surgery of 66 years. The mean follow-up was for 7.4 years (5 to 10.5). Recurrence of varus deformity was defined as an increase in the femorotibial angle of 3 degrees or more, compared with that obtained six months after the operation. There were four patients (four knees) with recurrence of varus deformity. They had a greater varus inclination of the distal femur than those without varus recurrence. An association between varus inclination of the distal femur and horizontal obliquity of the joint surface was observed. Excessive obliquity prevents the shift of weight-bearing to the lateral compartment, and may cause a recurrence of varus deformity after high tibial osteotomy.

Gouty tophus of the patella evaluated by PET imaging

We report a case of gouty tophus of the patella, a rare lesion, which was evaluated using positron emission tomography (PET). This modality, which uses a combination of an amino-acid analog emitter, L-[3-(18)F]-alpha-methyl tyrosine (FMT), which neglects malignancies, and a glucose analog emitter, (18)F-fluoro-2-deoxy-D-glucose (FDG), which neglects benign lesions, simulating the radiographic findings, may be useful for the preoperative evaluation of gouty tophus occurring in patella partita, including detection, differentiation from malignant tumors, and possible pathogenetic diagnosis.

Knee stability after repair of isolated midsubstance tears of the posterior cruciate ligament

This study was made to compare the results after operative versus non-operative management for tears in the substance of posterior cruciate ligament. The subjects were 40 patients, half of whom were managed operatively and the other half non-operatively. End-to-end suture was performed on the operated group. The procedure was followed by cast immobilization for 4 weeks. Non-operative management consisted of immobilization in a cast for 4 weeks after arthroscopy. The average follow-up periods were 6 years 7 months and 4 years 3 months. The operated knees were significantly more stable than those of the non-operated group on stress radiographs (p<0.0001), but not to the extent of an age-matched control group (p<0.0001). The knee rating scores did not indicate any improvement of the functional outcome in the operated group. Surgery resulted in better posterior laxity than non-operative management; the achieved stability, however, was clearly less than in controls.

The natural history of disappearing bone tumours and tumour-like conditions

We describe 27 cases of bone tumours or tumour-like lesions where there was spontaneous regression. The follow-up period was 2.8-16.7 years (average, 7.0 years). Fourteen of these cases were no longer visible on plain radiographs. Histological diagnosis included exostosis, eosinophilic granuloma, fibrous dysplasia, fibrous cortical defect, non-ossifying fibroma, osteoid osteoma and bone island. Most cases began to reduce in adolescence or earlier, although sclerotic type lesions showed their regression in older patients. All lesions thought to be eosinophilic granuloma began to regress after periods of less than 3 months, while the duration of the other lesions showed wide variation (1-74 months). As resolution of the lesions took between 2 and 79 months (mean, 25.0 +/- 20.3 months) we consider that the most likely mechanism was recovery of normal skeletal growth control. In exostosis with fracture, alteration of vascular supply may contribute to growth arrest, but not to subsequent remodelling stage. In inflammatory-related lesions such as eosinophilic granuloma, cessation of inflammation may be the mechanism of growth arrest, whilst temporary inflammation may stimulate osteogenic cells engaged in remodeling. In the sclerotic type, growth arrest is a less probable mechanism. Necrosis within the tumour and/or local changes in hormonal control, plus remodelling of the sclerotic area takes longer. Knowledge of the potential for spontaneous resolution may help in management of these tumour and tumour-like lesions of bone.

Propofol activates vanilloid receptor channels expressed in human embryonic kidney 293 cells

Propofol (2,6-diisopropylphenol) is an intravenous anesthetic agent structurally unrelated to any other intravenous anesthetics. We examined the effect of propofol on a rat vanilloid receptor that was expressed in the human embryonic kidney (HEK) 293 cells by using calcium imaging method. Propofol caused a concentration-dependent increase in [Ca(2+)](i) in the HEK293 cells with the receptor. These responses were inhibited by removing extracellular calcium ions. The propofol-evoked increase in [Ca(2+)](i) in the HEK293 cells with the receptor was partially inhibited by capsazepine, a competitive antagonist of capsaicin. We conclude that propofol acts as an agonist for the receptor.

Alcohol and the pancreas

This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The presentations were (1) Phenotypic alteration of myofibroblast during ethanol-induced pancreatic injury: its relation to bFGF, by Masahiko Nakamura, Kanji Tsuchimoto, and Hiromasa Ishii; (2) Activation of pancreatic stellate cells in pancreatic fibrosis, by Paul S. Haber, Gregory W. Keogh, Minoti V. Apte, Corey S. Moran, Nancy L. Stewart, Darrell H.G. Crawford, Romano C. Pirola, Geoffrey W. McCaughan, Grant A. Ramm, and Jeremy S. Wilson; (3) Pancreatic blood flow and pancreatic enzyme secretion on acute ethanol infusion in anesthetized RAT, by H. Nishino, M. Kohno, R. Aizawa, and N. Tajima; (4) Genotype difference of alcohol-metabolizing enzymes in relation to chronic alcoholic pancreatitis between the alcoholic in the National Institute on Alcoholism and patients in other general hospitals in Japan, by K. Maruyama, H. Takahashi, S. Matsushita, K. Okuyama, A. Yokoyama, Y. Nakamura, K. Shirakura, and H. Ishii; and (5) Alcohol consumption and incidence of type 2 diabetes, by Katherine M. Conigrave, B. Frank Hu, Carlos A. Camargo Jr, Meir J. Stampfer, Walter C. Willett, and Eric B. Rimm.

Factors affecting long-term results after arthroscopic partial meniscectomy

The purpose of this study was to determine functional and radiographic changes on long-term followup of knees with isolated meniscal tears. Sixty-seven patients were evaluated retrospectively with an average of 12.2 years' followup using the scale of Tapper and Hoover. The criteria for the radiographic results were the Fairbank's changes as the standard comparing the preoperative and the postoperative conditions of the affected knee with the contralateral knee. Seventy-nine percent of the patients had a satisfactory outcome in terms of function. The amount of meniscus removed and the Outerbridge classification of the articular cartilage at the time of the meniscectomy were determining factors for long-term functional results. Osteoarthritic deterioration was seen in 48% of patients after the surgery, but radiographic deterioration after arthroscopic partial meniscectomy was mild on long-term followup. Medial meniscectomy and the amount of meniscus removed were risk factors for postoperative radiographic change. Age, gender, and the degree of cartilage degeneration at the time of operation, in contrast, showed no significant association. Arthroscopic partial meniscectomy for isolated meniscal injury yields favorable functional results but leads to significantly increased osteoarthritic change in the long-term.

The management of medial ligament tears in patients with combined anterior cruciate and medial ligament lesions

The management of patients with combined medial collateral (MCL) and anterior cruciate (ACL) rupture remains controversial. We studied 25 such patients who elected to have the ACL lesion treated conservatively; 14 underwent MCL repair with early mobilization and 11 were treated with immobilization for two weeks. The mean follow up was 5.9 years (2 to 11). There was no difference in the clinical assessment of ligamentous laxity, KT-1000 measurements or Tegner activity scores between the two groups but there were significantly higher Lysholm function scores in the operated group.

[Preliminary survey of illegal drug misuse among Japanese high school students]

For several years, amphetamine misuse by high school students has been increasing in Japan. The Japanese National Police Agency announced that the third widespread use of amphetamines has started, especially among adolescents. However, there are few data on misuse of amphetamines or other substance abuse among high school students except for solvent inhalation. This is a preliminary survey report concerning substance abuse and substance-related problems among high school students. We surveyed 3393 high school students from 8 high schools in Kanagawa Prefecture and Kyushu Area on drinking and smoking status, and experience of illegal substance use. The results showed that 5.1% of the high school students had experiences of solvents inhalation, 1.1% of marijuana use, and 0.8% of amphetamine use. Around these illegal drug misusers, there were many reserves, such as students who experienced temptation to use solvents (13.6%), marijuana (2.4%), and amphetamines (2.5%), and those who responded that they wanted to use solvents (3.7%), marijuana (3.5%), and amphetamines (2.4%) if they were tempted. The prevalence of illegal drug misusers and reserves was not significantly different between male and female students, and they were concentrated among problem drinkers by the QF Scale and among current smokers. Prevalence of illegal drug misuse among Japanese high school students can not be estimated from the results of the survey because the subjects were limited to two areas and a small number of schools.

Mutation in the alpha-synuclein gene and sporadic Parkinson's disease, Alzheimer's disease, and dementia with lewy bodies

Recently, alpha-synuclein attracted attention when Polymeropoulos and colleagues identified a missense mutation of this gene (Science 276:2045-2047, 1997), which is responsible for a form of early-onset familial Parkinson's disease (PD). Immunohistochemically, alpha-synuclein is localized in Lewy bodies, characteristic brain pathology of PD, dementia with Lewy bodies (DLB), and Alzheimer's disease (AD), suggesting that this protein may link these common neurological diseases. Exploration of the possibility that the same mutation of the alpha-synuclein gene as that in familial PD (Ala53Thr) may also confer susceptibility to sporadic PD, DLB, and AD revealed the mutation in none of the samples of 329 cases and 230 controls examined, suggesting that this mutation is not involved in these neurological diseases.

The treatment of neuroleptic malignant syndrome using dantrolene sodium

The use of dantrolene sodium (DS) in the treatment of neuroleptic malignant syndrome (NMS) was studied from the data of 21 cases of NMS, which satisfied the diagnostic criteria of Pope et al. The mean dosage of DS was 0.97+/-0.52 mg/kg per day and the mean duration of treatment was 8.3+/-5.3 days. It was confirmed that the mean duration of treatment with DS tended to be longer in the cases involving disturbance of consciousness. However, there were no significant differences in the duration of treatment or the mean daily dosage, in the cases without disturbance of consciousness regardless of any other complications and symptoms. Also, there were no significant differences in the mean duration of treatment using DS and the mean dosage of DS between five cases that were considered to be 'typical' and 16 cases that were considered to be 'incomplete'. In addition, the prognoses of these cases were good such that not even one death occurred. In 13 cases, the treatment of psychiatric symptoms with thioridazine was started without recurrence of NMS.

Alcohol-related cancers and aldehyde dehydrogenase-2 in Japanese alcoholics

Aldehyde dehydrogenase-2 (ALDH2) eliminates most of the acetaldehyde produced during alcohol metabolism. In some drinkers, a mutant ALDH2 allele contributes to diminished activity of the enzyme, dramatically increasing the risk for esophageal cancer. This study was designed to evaluate the ALDH2 gene polymorphism as a predictor of the development of cancers prevalent in Japanese alcoholics. We performed ALDH2 genotyping on lymphocyte DNA samples from Japanese alcoholic men (487 cancer-free; 237 with cancer, including 34 oropharyngolaryngeal, 87 esophageal, 58 stomach, 46 colon, 18 liver, 7 lung, 9 other sites, and 19 multiple primary cancers in two or three organs). The frequencies of the mutant ALDH2*2 allele were significantly higher in alcoholics with oropharyngolaryngeal (52.9%), esophageal (52.9%), stomach (22.4%), colon (21.7%) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (78.6%), than in cancer-free alcoholics (9.0%). After adjustment for age, daily alcohol consumption and amount of cigarette smoking, significantly increased risks (odds ratios) in the presence of the ALDH2 *2 allele were found for oropharyngolaryngeal (11.14), esophageal (12.50), stomach (3.49), colon (3.35), lung (8.20) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (54.20) but not for liver or other cancers. These results suggest a general role of acetaldehyde, a recognized animal carcinogen, in the development of human cancers.

Imaging features of subcutaneous sarcoidosis

OBJECTIVE

This report describes subcutaneous sarcoidosis, focusing on the radiological and magnetic resonance (MR) features of the disease.

DESIGN AND PATIENTS

The cases of four patients (one male and three female, age range 36-75 years) who had subcutaneous sarcoidosis with no other organs affected were reviewed. Lesions were nodular in two cases, and in the other two were diffuse.

RESULTS

Computed tomography (CT) demonstrated a well-defined, homogeneous, and enhanced lesion in the nodular cases. However, in the diffuse cases, CT showed a heterogeneous, honeycomb-like appearance and little enhancement. Angiography showed a fine stain in the arterial phase. MR imaging of the nodular lesions was homogeneous with a signal intensity similar to muscle on T1-weighted images but heterogeneous with a higher signal than muscle on T2-weighted images. Diffuse lesions showed a striped or mesh pattern with intermediate signal intensity on both T1- and T2-weighted images. Contrast-enhanced MR images showed slight enhancement.

CONCLUSIONS

Subcutaneous sarcoidosis should be considered in the differential diagnosis when a patient presents with the radiological and MR features described.

Analysis of muscle bioenergetic metabolism in rabbit leg lengthening

The effect of lengthening on muscle metabolism was measured and correlated to the percent lengthening at early and late time points. Using the rabbit tibial lengthening model, the authors examined the effects of lengthening on the tibialis anterior muscle using phosphorus-31 magnetic resonance spectroscopy. Thirty-six rabbits were divided into five groups, four groups by percent lengthening (0%, 15%, 20%, and 25%), with each group divided into subgroups of early (end distraction) and late (12 weeks after end distraction), and the fifth group using the opposite untreated leg as control. Several parameters measuring metabolism of muscle using phosphorus-31 magnetic resonance spectroscopy analysis were compared. No changes occurred to 15% lengthening, but significant decreases were measured at 20% and 25% lengthening. After a 25% lengthening, the decreased metabolism persisted at 12 weeks after distraction, indicating the possibility of permanent damage. After 20% lengthening, the same parameters improved but never to normal levels. The authors conclude that lengthening to 15% is safe for muscle, but 20% to 25% lengthening may result in permanent metabolic damage. The current study also suggests that phosphorus-31 magnetic resonance spectroscopy may provide a viable clinical method for evaluating muscle damage during lengthening.

The influence of osteoporosis on varus osteoarthritis of the knee

We studied 37 patients with varus osteoarthritis of the knee to determine the influence of the bone mineral density (BMD) on the varus deformity. There were 15 men (21 knees) and 22 women (38 knees). The mean age of the men was 69 years and of the women 68 years. BMD was measured in the L1-L4 spinal region using dual X-ray absorptiometry. In the women a low level of BMD was associated with varus deformity originating at the proximal tibia, but a high level was predominantly linked with deformity originating in the joint space. Similar findings were obtained in the men. Our results suggest that a low BMD predisposes to trabecular microfractures and consequently increased stress on the articular cartilage. A low BMD does not preclude osteoarthritic change in the knee.

The influence of osteoporosis on varus osteoarthritis of the knee

We studied 37 patients with varus osteoarthritis of the knee to determine the influence of the bone mineral density (BMD) on the varus deformity. There were 15 men (21 knees) and 22 women (38 knees). The mean age of the men was 69 years and of the women 68 years. BMD was measured in the L1–L4 spinal region using dual X-ray absorptiometry.

In the women a low level of BMD was associated with varus deformity originating at the proximal tibia, but a high level was predominantly linked with deformity originating in the joint space. Similar findings were obtained in the men.

Our results suggest that a low BMD predisposes to trabecular microfractures and consequently increased stress on the articular cartilage. A low BMD does not preclude osteoarthritic change in the knee.

Calcific tendinitis in the posterior proximal thigh as a self-limited condition: pathogenic role of inflammatory responses

OBJECTIVE

Calcific tendinitis occurs rarely in the posterior proximal thigh. We investigated whether it is self-limited and how the natural course of the disease progresses.

METHODS

We treated 6 patients with no surgical intervention, and analyzed laboratory and radiological findings in the followup period of more than one year (average followup, 2.5 yrs).

RESULTS

Although tendinitis was severe, rapid relief was observed within 2 weeks (average 5 days). Radiological features including extraskeletal calcifications did not change within 2 weeks, and then improved by 6 weeks. Four of 6 cases showed abnormal laboratory variables. All elevated white blood cell counts and C-reactive protein levels improved within one week with clinical resolution. In comparison with time course of the symptoms, changes in the radiological findings over time appeared not to be parallel with the clinical course, but laboratory progression appeared to correspond well with clinical resolution.

CONCLUSION

Inflammatory responses to hydroxyapatite crystals may play a role in the pathogenesis of symptoms of calcific tendinitis in the posterior proximal thigh, most of which are self-limited.

Free synovium promotes meniscal healing. Synovium, muscle and synthetic mesh compared in dogs

We studied the effect of free synovium on the healing of tears in the avascular portion of the menisci in dogs. A longitudinal incision was made in the medial meniscus. In 35 dogs, a free graft of synovium was inserted into the tear and sutured. In 10 dogs, a free graft of quadriceps muscle was used. In 10 dogs, a Dacron mesh was inserted. In the contralateral knee, the tear was sutured without implantation as a control. 2, 4, 6, 8, and 12 weeks after the operation, the menisci were dissected. 11 of the 35 with free synovium were healed. The menisci with muscle grafts, those with Dacron mesh and those in the control group did not heal. Histology showed that tears were repaired with fibrous tissue. Microangiography showed that capillaries grew from the periphery, but they did not reach the tear.

Separated ossicles of the lateral malleolus

Sixty ankles of 59 patients with symptomatic ossicles of the lateral malleolus were studied. All patients underwent clinical and radiographic examinations. Stress arthrography was performed on 58, arthroscopy on 48, operative treatment on 52, and histologic examination on 23. The ossicles were classified into 3 sizes (small, medium, and large) and 2 levels (A and B) by location. The relationship between the ossicle and fibular tip was classified into 3 grades according to arthrography results (Grade 1, little inflow [< 1 mm] of the contrast medium; Grade 2, an apparent space [1-2 mm]; Grade 3, a large gap [> 2 mm]) and to operative and arthroscopic findings (Type A, a fibrous union; Type B, a partial continuity; Type C, a lax thin scar tissue; Type D, no continuity). There were significant differences in talar tilt angles on stress radiography between the 3 grades. Chronic symptoms had a tendency to increase from Grade 1 to Grade 3 and from Type A to Type C or D, with instability occurring more than pain. The size and level did not correlate with instability. Acute or chronic inversion forces may act on the connection between the ossicle and fibular tip, and damage to this structure may cause symptoms.

Entrapment neuropathy of the deep peroneal nerve associated with the extensor hallucis brevis

The authors report a case of entrapment neuropathy of the deep peroneal nerve associated with the extensor hallucis brevis. This entrapment neuropathy was found distal to the inferior retinaculum that causes the anterior tarsal tunnel syndrome. Surgical decompression of the deep peroneal nerve that was entrapped by the extensor hallucis brevis relieved the symptoms. This condition, like the anterior tarsal tunnel syndrome, deserves attention.

The natural history of untreated anterior cruciate tears in recreational athletes

A followup study was performed to elucidate the natural course of acutely torn anterior cruciate ligaments in recreational athletes. Fifty-six consecutive patients had arthroscopy within 2 weeks of their initial injuries; however, no surgery was done on the torn anterior cruciate ligament. Twenty anterior cruciate ligament and medial collateral ligament combined ruptures occurred. Patient ages ranged from 14 to 50 years old (mean, 28.9 years). Followup periods ranged from 2 to 10 years (mean, 5 years 6 months). Through examination with the KT-1000 arthrometer, side-to-side differences of anterior translation of the tibia of > or = 3 mm in 72% patients at reexamination were seen. Eight of 46 patients had mild osteoarthritic changes of Grade 1 visible on radiographs, but only 1 patient reported knee trouble. Nine patients had repeat injuries, 3 of whom had late reconstructions and 4 late meniscectomies. Functional scores averaged 95 +/- 6.5 points. Activity scores averaged 4.8 +/- 1.6 points. Operative management for the medial structure did not improve the stability better than nonoperative management. Anterior translation and functional scores of patients with medial meniscectomies showed significant differences from those of other patients. Anterior cruciate ligament reconstruction for recreational athletes should be considered when the patients have reparable meniscal tears, and meniscal repairs should be performed simultaneously.

Axial parameters affecting lower limb alignment after high tibial osteotomy

Lower limb alignment of 46 knees treated with high tibial osteotomy was studied to find a method for determining the precise correction angle. The femorotibial angle was divided into several axial alignment parameters. Before the operations, the femorotibial angle correlated with the tilting angle of the femoral shaft toward the horizontal (femoral shaft-horizontal angle) and that of the tibial shaft toward the horizontal (tibial shaft-horizontal angle). After the operations, the femorotibial angle correlated with the tibial shaft-horizontal angle, but not with the femoral shaft-horizontal angle. The postoperative femoral shaft-horizontal angle tends to be constant regardless of the degree of valgus. In preoperative varus knees, the varus deformity increases the degree of shift of the femoral and tibial shaft toward the varus direction. In postoperative valgus knees, the more valgus the knee the more the tibial shaft shifted toward the valgus direction, which was not true for the femoral shaft. The femorotibial angle was influenced more by the tibial axial alignment in the postoperative valgus knee. The slope of the distal femoral articular surface influenced the tilt of tibial articular surface toward the horizontal which, in turn, influenced the tibial shaft-horizontal angle. The authors recommend relying on the tibial axial alignment parameter to determine the amount of correction. The slope of the distal femoral articular surface should be considered in preoperative planning.

Second look arthroscopy after meniscal repair. Factors affecting the healing rate

Second look arthroscopy was performed on 46 of 137 consecutive patients who underwent arthroscopic meniscal repair. All tears were of the vertical type. Thirty-two tears were located in avascularized areas. Thirty-one patients had associated anterior cruciate ligament insufficiencies. Anterior cruciate ligament reconstructions were performed simultaneously on 26 patients. The double-needle cannula method was used in all the patients. An additional transplantation of a vascularized synovial pedicle flap to the suture site was performed on 7 tears in avascularized areas. Second look arthroscopy showed no healing in 8 patients and healing in 38. Four of the 8 unhealed tears were located in avascularized areas, and 4 had unreconstructed anterior cruciate ligament injuries respectively. All 7 patients with synovial pedicle flaps showed healing. All patients with anterior cruciate ligament reconstructions showed healing, and the healing rate was significantly higher than that of the other patients (p < 0.005). Patients with anterior cruciate ligament insufficiencies showed a significantly lower healing rate than the others (p < 0.005). In patients with tears in avascularized areas, the conventional meniscal repairs showed a lower healing rate than did the repairs with a synovial pedicle transplantation or an anterior cruciate ligament reconstruction (p < 0.005). These results suggest that the most important factors influencing meniscal healing are the presence of anterior cruciate ligament tears, ligamentous reconstruction, and vascularity of the tear site.

Untreated acute anterior cruciate ligament tears of the knee: progression and the influence of associated injuries

Arthroscopy was performed on 53 consecutive patients with acutely torn ACL within two weeks after the initial injury. Arthrography was performed on 42 of the 53 patients prior to arthroscopy. Four Segond's fractures, twenty-six meniscus tears (eight medial, eighteen lateral) and nineteen medial collateral ligament (MCL) ruptures were revealed. One medial meniscectomy was performed under arthroscopy, and ten MCL tears were repaired in the acute phase. No surgical procedure was done on the torn ACL, but three excisions of ACL stubs were performed due to a restriction of full extension. The patients were re-examined clinically and radiographically after a period of from 3 years 7 months to 11 years 1 month, averaging 6 years 2 months. Four late meniscectomies were performed on the medial menisci in the chronic phase. Anterior translations of the tibia and knee rating scores of the patients with MCL tears and with Segond's fractures did not differ from those of the others. Anterior translations of the tibia in patients with medial meniscectomies increased (P < 0.05), and their functional scores significantly decreased (P < 0.01) more than those of the other patients. Patients with repaired MCL tears showed significantly higher functional scores than those of the patients with unrepaired MCL ruptures (P < 0.05).

Scapulohumeral reflex (Shimizu). Its clinical significance and testing maneuver

Searching for a muscle stretch reflex that is innervated by the high cervical cord, the authors discovered the scapulohumeral reflex (Shimizu)--SHR (Shimizu). The testing maneuver, localization of the reflex center, its clinical significance, and the designation of the SHR (Shimizu) are dealt with in this report. The SHR is elicited by tapping the tip of the spine of the scapula and acromion in a caudal direction. The SHR is classified as hyperactive only when an elevation of the scapula or an abduction of the humerus have been clearly defined after tapping at these points. Two hundred twenty-five patients with cervical spine disorders, 90 normal individuals, and 17 patients with cerebrovascular strokes were examined. The incidence of hyperactive SHR was highest among several neurologic abnormalities in spastic cases with craniovertebral or high cervical lesions, and all cases with hyperactive SHR in the cervical spine disorder group exhibited neural compressive factors at the high cervical region. The major muscles participating in the SHR are considered to be the upper portion of the trapezius, the levator scapulae, and the deltoid. According to the anatomic level of compressive factors and the postoperative course of the activity in hyperactive SHR cases, the reflex center of the SHR is clinically presumed to be located between the posterior arch of C1 and the caudal edge of the C3 body. Hyperactive SHR provides useful information about dysfunctions of the upper motor neurons cranial to the C3 vertebral body level.