Anatomic Variations of the Flexor Carpi Radialis Brevis: A Report of Five Cases

The flexor carpi radialis brevis (FCRB) is a rare, anomalous musculotendinous structure of the wrist. Here, we report five cases of FCRB in a consecutive series of 123 distal radius fractures that were repaired by using volar locking plates.

Inhibition of Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway in rheumatoid synovial fibroblasts using small molecule compounds

Janus kinase (JAK) inhibitors have been developed as anti-inflammatory agents and have demonstrated clinical efficacy in rheumatoid arthritis (RA). We investigated if JAK-3-selective inhibition alone could disrupt cytokine signalling in rheumatoid synovial fibroblasts. In-vitro studies were performed using synovial fibroblasts isolated from patients with RA. Levels of activated JAK and signal transducer and activator of transcription (STAT) proteins were detected by immunoblot analysis. Target-gene expression levels were measured by reverse transcription-polymerase chain reaction (RT-PCR) or real-time PCR. The JAK inhibitors CP-690,550 and INCB028050 both suppressed activation of JAK-1/-2/-3 and downstream STAT-1/-3/-5, as well as the expression levels of target proinflammatory genes (MCP-I, SAA1/2) in oncostatin-M (OSM)-stimulated rheumatoid synovial fibroblasts. In contrast, the JAK-3-selective inhibitor, PF-956980, suppressed STAT-1/-5 activation but did not affect STAT-3 activation in OSM-stimulated rheumatoid synovial fibroblasts. In addition, PF-956980 significantly suppressed MCP-1 gene expression, but did not block SAA1/2 gene expression in OSM-stimulated rheumatoid synovial fibroblasts. These data suggest that JAK-3-selective inhibition alone is insufficient to control STAT-3-dependent signalling in rheumatoid synovial fibroblasts, and inhibition of JAKs, including JAK-1/-2, is needed to control the proinflammatory cascade in RA.

Serum amyloid A triggers the mosodium urate -mediated mature interleukin-1β production from human synovial fibroblasts

Background

Monosodium urate (MSU) has been shown to promote inflammasome activation and interleukin-1β (IL-1β) secretion in monocyte/macrophages, but the cellular pathway and nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in synovial tissues, remain elusive. In this study, we investigated the effects of MSU on synovial fibroblasts to elucidate the process of MSU-mediated synovial inflammation.

Methods

Human synovial fibroblasts were stimulated with MSU in the presence or absence of serum amyloid A (SAA). The cellular supernatants were analyzed by immunoblotting using anti-IL-1β or anti-caspase-1 antibodies. IL-1β or NLRP3 mRNA expressions were analyzed by real-time PCR or reverse transcription-PCR (RT-PCR) method.

Results

Neither SAA nor MSU stimulation resulted in IL-1β or interleukin-1α (IL-1α) secretions and pro-IL-1β processing in synovial fibroblasts. However, in SAA-primed synovial fibroblasts, MSU stimulation resulted in the activation of caspase-1 and production of active IL-1β and IL-1α. The effect of SAA on IL-1β induction was impaired in cells by silencing NLRP3 using siRNA or treating with caspase-1 inhibitor. In addition, SAA induced the secretion of cathepsin B and NLRP3 mRNA expression in synovial fibroblasts.

Conclusions

Our data demonstrate that exposure of human synovial fibroblasts to SAA promotes MSU-mediated caspase-1 activation and IL-1β secretion in the absence of microbial stimulation. These findings provide insight into the molecular processes underlying the synovial inflammatory condition of gout.

Serum amyloid A (SAA) induces pentraxin 3 (PTX3) production in rheumatoid synoviocytes

OBJECTIVE

Pentraxin 3 (PTX3) is an acute-phase reactant that is involved in amplification of the inflammatory response and innate immunity. In the present study, we evaluated the relationship between PTX3 and serum amyloid A (SAA), another acute-phase reactant, in rheumatoid synoviocytes.

METHODS

PTX3 mRNA expression was examined by reverse transcription polymerase chain reaction, and PTX3 protein was measured by enzyme-linked immunosorbent assay.

RESULTS

SAA induced PTX3 mRNA and PTX3 protein expression in rheumatoid synoviocytes. SAA-induced PTX3 expression was attenuated when rheumatoid synoviocytes were nucleofected with N-formyl peptide receptor ligand-1 (FPRL-1)-specific siRNA, suggesting the involvement of FPRL-1. Furthermore, SAA-induced PTX3 expression was inhibited by NF-κB or mitogen-activated protein kinase-specific inhibitors. Neither soluble TNF receptor (etanercept) nor recombinant IL-1 receptor antagonist affected PTX3 production by SAA-stimulated synoviocytes, suggesting that SAA directly induces PTX3.

CONCLUSION

Our data suggest that SAA plays a role in the proinflammatory and immune responses in rheumatoid synovium by inducing PTX3. We provide the first evidence that the acute-phase reactant SAA, which is produced systemically by hepatocytes, perpetuates the rheumatoid inflammatory processes by inducing another proinflammatory molecule, PTX3, locally in rheumatoid synovial tissues.

Angioplasty decreases prolonged QT dispersion in patients with angina pectoris but not in patients with prior myocardial infarction

BACKGROUND AND HYPOTHESIS

Prolonged QT dispersion (QTd) is shortened by successful percutaneous transluminal coronary angioplasty (PTCA) in patients with ischemic heart disease. Particularly, QTd plays an important role in the prognostication in patients with prior myocardial infarction (MI). However, whether the effect of PTCA on QTd differs in patients with and without prior MI is not clear, and this study sought to clarify this question.

METHODS

In 41 consecutive patients with ischemic heart disease, we measured QTd from a routine 12-lead electrocardiogram taken at 72 h before and after successful PTCA. Patients were divided into two groups based on the presence or absence of prior MI: Group 1 consisted of 24 patients with angina (61 +/- 11 years old) without prior MI and Group 2 was comprised of 17 patients (69 +/- 10 years old) with prior MI. QTd was calculated as the difference between the maximum and minimum QT and QT corrected for heart rate (QTc), using Bazett's formula for calculating QTcd. All measurements were obtained manually and blindly.

RESULTS

In Group 1, 15 of 24 patients (63%) demonstrated multivessel disease and 16 of 24 (67%) patients had high QTd > 60 ms. Percutaneous transluminal coronary angioplasty decreased QTd and QTcd in Group 1 (QTd, from 83 +/- 35 to 57 +/- 19 ms, p < 0.05 ; QTcd, from 89 +/- 37 to 63 +/- 33 ms, p < 0.05), whereas no changes were observed in Group 2 (QTd, from 73 +/- 25 to 69 +/- 22 ms, NS; QTcd, from 80 +/- 30 to 79 +/- 28 ms, NS). QTd is more sensitive to decrease by successful PTCA in patients with angina than in patients with prior MI.

CONCLUSIONS

The effect of successful PTCA on inhomogeneity of ventricular repolarization reflected by QTd in patients with prior MI is different from that in patients without prior MI.

Effect of aprindine on heart rate variability indices in patients with ischemic heart disease

BACKGROUND

Decreased heart rate variability indices (HRV) are associated with untoward outcome of patients with ischemic heart disease (IHD). Most class I antiarrhythmic agents decrease HRV, but aprindine (a new class I antiarrhythmic agent) is reported to increase HRV in patients without ischemia.

HYPOTHESIS

The study was undertaken to determine whether apridine might increase HRV in patients with IHD.

METHODS

To investigate the effect of aprindine on HRV in patients with IHD, we performed 24-h ambulatory electrocardiogram (ECG) at the end of placebo and aprindine (60 mg daily) treatment phases on 38 patients with IHD and at least isolated premature ventricular contractions (PVC). The study protocol utilized a single blind, 4-week, placebo-controlled design. Heart rate variability from ambulatory ECG included SDNN (ms), SDANN (ms), SD (ms), rMSSD (ms), pNN50 (%); frequency analysis of HRV consisting of total (ms, 0.01-1.00 Hz), low (ms, 0.04-0.15 Hz), and high (ms, 0.15-0.40 Hz) components.

RESULTS

Study patients were divided into three groups according to the severity of IHD and antiarrhythmic efficacy of aprindine. Group 1 consisted of 15 patients with angina with single-vessel disease, and Group 2 was composed of 10 patients with either multivessel disease or post myocardial infarction; PVCs decreased in both groups as result of aprindine treatment. Group 3 consisted of 13 patients who showed no decreased PVC after aprindine treatment. RMSSD increased, and pNN50 and high-frequency spectra tended to increase in Group 1, while SD, rMSSD, pNN50, and total and low-frequency spectra decreased in Group 3; no significant changes were observed in Group 2. Aprindine significantly augments vagal activity, as reflected by the increase of rMSSD, pNN50, and high-frequency spectra in mild IHD.

CONCLUSION

These salutary effects are less in more severe IHD, but aprindine does not aggravate HRV. Thus, if there are salutary effects on arrhythmias and no proarrhythmic effects, aprindine could be prescribed to patients with IHD without concern about decreasing HRV.

Morning attenuation of endothelium-dependent, flow-mediated dilation in healthy young men: possible connection to morning peak of cardiac events?

BACKGROUND AND HYPOTHESIS

Brachial artery flow-mediated dilation (FMD), a noninvasive, widely used clinical index of endothelial function and magnitude of FMD, has been reported to be closely related to many coronary risk factors and coronary atherosclerosis. However, there has been no study that examines the diurnal change of FMD. We designed this study to reveal the diurnal variation of FMD in healthy volunteers.

METHODS

We examined FMD in response to reactive hyperemia by high resolution ultrasound in 13 healthy young men (age 25-32) at four different times over the course of a day.

RESULTS

Mean measures of brachial artery FMD was 4.0% at 8:00, 5.3% at 12:00, 9.7% at 17:00, and 6.9% at 21:00 hours. Flow-mediated dilation at 8:00 and at 12:00 hours was significantly lower than that at 17:00 (p < 0.05).

CONCLUSIONS

These results show that endothelial function has diurnal variation and is significantly attenuated in the morning. Morning attenuation of endothelial function should be recognized in clinical research and may play an important role in the circadian variation of the occurrence of acute cardiovascular events.

Endothelial dysfunction and decreased exercise tolerance in interferon-alpha therapy in chronic hepatitis C: relation between exercise hyperemia and endothelial function

BACKGROUND

We previously reported that reversible endothelial dysfunction is caused by interferon-alpha therapy (IFN) in patients with chronic hepatitis C. In experimental studies, limb blood flow during exercise is reported to be dependent on endothelium-derived nitric oxide.

HYPOTHESIS

The purpose of this study was to confirm the effect of IFN on endothelial function and to investigate whether exercise hyperemia is dependent on endothelial function in humans.

METHODS

We performed symptom-limited exercise treadmill testing and measured flow-mediated vasodilation (FMD, endothelium-dependent vasodilation) and sublingual glyceryl-trinitrate-induced dilation (GTN-D, 0.3 mg, endothelium-independent vasodilation) in the brachial artery by using high-resolution ultrasound in 10 patients with chronic active hepatitis C (age 53 +/- 11 years, 2 men, 8 women) before and immediately after administration of recombinant interferon 2b (10 million U/day) for 4 weeks.

RESULTS

There were no significant abnormal findings in any patients in routine studies of 24-h ambulatory electrocardiogram monitoring, two-dimensional echocardiography, and exercise treadmill testing both before and after treatment. Leg fatigue and exhaustion were the reasons for termination of exercise treadmill testing in each patient. Pressure rate product was calculated at rest and peak exercise. Interferon-alpha therapy significantly (p<0.05) decreased FMD (6.8 +/- 3.1 vs. 1.9 +/- 2.6%), exercise treadmill testing tolerance time (437 +/- 89 vs. 395 +/- 62 s) and peak pressure rate product (283 +/- 41 vs. 241 +/- 47 mmHg x beats/min x 10(-2)), but not GTN-D (13.4 +/- 5.4 vs. 17.0 +/- 5.5%). The change of FMD due to IFN significantly and highly correlated with exercise treadmill testing tolerance time (r = 0.86, p<0.001), but not with change of peak pressure rate product, suggesting that FMD is more closely related to the condition of the peripheral circulation than is cardiac performance.

CONCLUSION

These results suggest that IFN in patients with chronic hepatitis C impairs endothelial function and exercise tolerance, and that endothelial function might be at least partly involved in exercise hyperemia in humans.

Significance of circulatory epinephrine levels in exercise-induced neurally mediated syncope

BACKGROUND AND HYPOTHESIS

Previous research has failed to document temporal changes in epinephrine levels in patients with neurally mediated syncope associated with exercise. The purpose of this study was to investigate the role of circulatory catecholamines in exercise-induced neurally mediated syncope, specifically focusing on epinephrine levels.

METHODS

The present study deals with temporal changes of circulatory catecholamine levels during head-up tilt tests (40 min, 80 degree tilt) in 62 patients with syncope of unknown origin, 7 of whom had syncope associated with exercise (exercise-induced group, 19+/-3 years). Data were compared with 10 control subjects (control group, 45+/-23 years). Of the 55 patients with syncope not associated with exercise, 32 tested positive for the head-up tilt tests (positive group, 31+/-16 years) and 23 patients tested negative (negative group, 46+/-19 years). Blood samples for circulatory catecholamine assay were obtained from the antecubital vein in the baseline supine position 2 min after the tilt started, every 10 min during tilt, and at the time of the onset of symptoms or the end of tilt. Levels of norepinephrine and epinephrine were determined using the high-pressure liquid chromatography (HPLC) method (pg/ml).

RESULTS

Plasma norepinephrine levels among the four groups were similar at the supine position and during tilt testing. In contrast, patients in the exercise-induced group had significantly higher maximum epinephrine levels during head-up tilt testing than the other three groups (288+/-191 vs. 148+/-117, 66+/-31, and 54+/-27 pg/ml, respectively, p < 0.05). Patients in the positive group had higher maximum epinephrine levels than those in the negative group (p <0.05). Also, patients in the exercise-induced group and those in the positive group had a significantly shorter tilt-testing time than patients in the negative and control groups.

CONCLUSIONS

A marked increase of epinephrine was observed during head-up tilt testing in patients with neurally mediated syncope associated with exercise. The present findings further accelerate the identification of the role of epinephrine in the mechanisms behind neurally mediated syncope associated with exercise.

Endothelial function and peripheral vasomotion in the brachial artery in neurally mediated syncope

BACKGROUND

Paradoxical peripheral vasodilation is one of the suspected mechanisms of neurally mediated syncope. Parasympathetic stimulation following sympathetic activation during orthostatic stress mainly contributes to this vasodilation.

HYPOTHESIS

Since endothelial function modulates peripheral vascular tone, this study aimed to determine whether endothelial function and inappropriate peripheral vasomotion has a significant role in the pathogenesis of neurally mediated syncope.

METHODS

To investigate whether endothelial function is augmented or whether abnormal peripheral vasomotion exits, flow-mediated dilation (FMD, endothelium-dependent vasodilation) and sublingual glyceryl trinitrate-induced dilation (0.3 mg, GTN-D, endothelium-independent vasodilation) were measured in the brachial artery in 16 patients with neurally mediated syncope, aged 33 +/- 10 years, by using high-resolution ultrasound. All patients underwent positive head-up tilt testing. These measures were compared with those in 16 control subjects matched with the patients by age, gender, and coronary risk factors. For FMD, percent diameter changes were obtained from baseline to hyperemic conditions (1 min after 5 min occlusion of the forearm artery). There were five smokers in both the patient and the control groups, but there was no structural heart disease in either group.

RESULTS

Baseline brachial artery diameters were comparable (3.8 +/- 0.6 vs. 3.8 +/- 0.7 mm, NS). Flow-mediated dilation in patients with neurally mediated syncope had a normal value of 9.8 +/- 5.0% despite the inclusion of five smokers. Flow-mediated dilation and GTN-D in patients with neurally mediated syncope were significantly greater than those in controls (9.0 +/- 5.0 vs. 3.0 +/- 3.5%, p<0.05; 18.4 +/- 5.5 vs. 14.1 +/- 4.4%, p<0.05).

CONCLUSIONS

Augmented endothelial function and/or abnormal peripheral vasomotion in peripheral arteries are important in patients with neurally mediated syncope in selected populations.

Frequency domain heart rate variability and plasma norepinephrine level in the coronary sinus during handgrip exercise

BACKGROUND

Heart rate (HR) variability has been recognized as an important noninvasive index of autonomic nervous activities. However, the relationship between HR variability and cardiac circulating norepinephrine (NE), especially with respect to coronary ischemia, remains unclear.

HYPOTHESIS

This study was undertaken to determine whether HR variability indices can reflect cardiac NE levels during handgrip exercise.

METHODS

We simultaneously measured HR variability and cardiac NE overflow rate in 32 patients (30 men, 2 women) during a 6-min isometric handgrip exercise. Among the 32 subjects, 20 (19 men, 1 woman) had coronary artery disease (CAD) and 12 (control group; 11 men, 1 woman) did not.

RESULTS

Hemodynamics and cardiac NE overflow rates among subjects at rest were not significantly different between the two groups. In the normal subjects, low-frequency (LF) spectra and LF/HF (high-frequency) ratios were not significantly changed during handgrip exercise, but HF spectra significantly increased from 10.1 +/- 4.5 to 12.2 +/- 7.0 ms (p < 0.05). In the subjects with CAD, LF and LF/HF spectra were significantly (p < 0.05 and 0.01, respectively) increased by handgrip exercise. High-frequency spectra were not significantly changed by handgrip exercise. In the normal subjects, a significant negative relation (r = -0.76, p < 0.01) was obtained between HF change and cardiac NE overflow rate, whereas this relationship was not significant in the subjects with CAD. The correlation between changes of LF/HF and cardiac NE overflow rate was significant in the normal (r = 0.56, p < 0.05) but not in subjects with CAD.

CONCLUSION

These results suggest that vagal modulation of HR variability is more prominent in normal coronary artery subjects than in CAD subjects during handgrip exercise. Heart rate variability indices may thus serve as adequate indicators of autonomic nerve activity in subjects with normal coronary arteries but not in those with CAD, probably due to decreased adaptation to physical stress during handgrip exercise.

Specific-wavelength visible light irradiation inhibits bacterial growth of Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

The effects of laser irradiation on Porphyromonas gingivalis have been reported, but the results are still controversial regarding the efficiency because of the differences of the light sources and irradiation conditions. The aim of this study was to determine the wavelength and irradiation conditions under which the most effective inhibitory effect on P. gingivalis growth was seen without any photosensitizers.

MATERIAL AND METHODS

Using an Okazaki large spectrograph, monochromatic light spectra ranging from 400 to 700 nm were evaluated to determine which spectra effectively inhibited bacterial growth. Moreover, using a monochromatic 405-nm irradiating device, the effects of various irradiating conditions on P. gingivalis growth were examined.

RESULTS

Growth of bacteria irradiated at 400 nm and 410 nm was significantly suppressed compared with a nonirradiated control, whereas wavelengths of 430 nm and longer produced no significant inhibition. A constant energy density of 15 J/cm2 was found to be enough to show an inhibitory effect. Significant inhibition of bacterial growth was found after only 1 min at 50 mW/cm2 irradiation.

CONCLUSION

These results indicate that P. gingivalis growth is specifically suppressed by 405-nm light irradiation, suggesting that visible blue light irradiation is a promising means for eradicating periodontopathogenic bacteria from periodontal lesions.

Side population cells expressing ABCG2 in human adult dental pulp tissue

AIM

To investigate the presence of side population (SP) cells by the Hoechst exclusion method in human adult dental pulp tissue.

METHODOLOGY

Human adult dental pulp-derived cells were generated from third molar teeth. The cells were stained with Hoechst 33342 and sorted into SP cells or non-SP cells [main population (MP) cells]. Both cell types were compared with cell growth and RT-PCR analyses.

RESULTS

SP cells that express ABCG2, Nestin, Notch-1 and alpha-smooth muscle actin were found at frequencies ranging from 0.67% to 1.02%. This SP profile disappeared in the presence of verapamil. These SP cells expressed dentine sialophosphoprotein and dentine matrix protein-1 when cultured in osteogenic medium.

CONCLUSION

Human adult dental pulp tissue contains SP cells that differentiate into odontoblast-like cells.

Osteopetrosis complicated by osteomyelitis of the mandible: a case report including characterization of the osteopetrotic bone

A case of a 53-year-old Japanese man with osteopetrosis complicated by osteomyelitis of the mandible is presented. The patient experienced frequent exacerbations and remissions of osteomyelitis of the mandible, despite undergoing several surgical debridements and sequesterectomies with appropriate antimicrobial therapy, for 3 years. Finally, the patient underwent mandibular segmental resection followed by reconstruction with a titanium reconstruction plate. Fifty-one months after surgery there is no evidence of recurrent osteomyelitis of the mandible, suggesting that a more radical surgical approach is preferable for patients with severe complications resulting from osteopetrosis. Also presented here are the histopathological and biochemical features of the osteopetrotic bone. The osteopetrotic cortical bone was morbidly sclerotic with compact and irregular laminations. Degradation of osteocytes in the osteopetrotic bone was due to hypoxia and lack of nutrition resulting from osteosclerosis. There were no significant differences between osteopetrotic and normal bone according to X-ray diffraction, Fourier transform infrared spectroscopy, collagen content or mineral content. Micro-Vickers hardness measurements showed that osteopetrotic bone was significantly harder than normal bone, and the standard deviation of hardness was greater in osteopetrotic bone. Such a loss of integrity in osteopetrotic bone is considered to be a primary reason for the greater risk of a variety of complications such as pathological fracture and refractory osteomyelitis.

Flow-mediated dilation in brachial artery in the second half of pregnancy and prediction of pre-eclampsia

Endothelial injury and increased vascular reactivity are involved in the pathogenesis of pre-eclampsia (pregnancy-induced hypertension). To investigate whether flow-mediated dilation (endothelium-dependent dilation) and the reactive hyperemic response can predict pre-eclampsia, we prospectively measured flow-mediated dilation and the Doppler flow velocity pattern (V, cm/s) in the brachial artery using high-resolution ultrasound in 43 pregnant women (32+/-5 years old) in the second half of their pregnancy, and compared the findings with traditional risk factors. Regarding the Doppler flow velocity pattern, the pulsatility index (PI)=(systolic V-diastolic V)/mean V and resistance index (RI)=(systolic V-diastolic V)/systolic V were calculated. For the flow-mediated dilation, the per cent diameter changes were determined based on those from baseline to hyperemic conditions. Nine women suffered from pre-eclampsia and 34 women remained normotensive. Only flow-mediated dilation was found to be significantly lower in the subsequently developed pre-eclampsia patients (1.6+/-1.0% in subsequently developed pre-eclampsia patients vs 11.0+/-4.5% in normotensive patients, P<0.05). Neither the other traditional factors nor the Doppler flow velocity pattern were significantly different between the subsequently developed pre-eclampsia and normotensive patients. If a normal cutoff value of 3.0% obtained from age-matched 14 nonpregnant women (32+/-7 years old) in our laboratory was used, the positive predictive value of flow-mediated dilation (<3.0%) for subsequent pre-eclampsia is 90% and the negative predictive value is 100%. In conclusion, flow-mediated dilation in brachial artery can be a simple and noninvasive modality to predict pre-eclampsia.

Expression of matrix metalloproteinase 3 in experimental atherosclerotic plaques

In atherosclerotic lesions, matrix metalloproteinases produced by foam cells (macrophages) are thought to increase plaque instability, promote plaque rupture, by degradating extracellular matrix. To investigate the relationship between the expression of these proteinases and the histologic appearance of atheromas, immunohistochemical analysis of matrix metalloproteinase 3 and cell-type markers was performed in atherosclerotic plaques induced in rabbit abdominal aortas by high-cholesterol diets and mechanical injury. In addition to an antibody against matrix metalloproteinase 3, RAM-11 and HHF-35 were used to detect macrophages and smooth muscle cells, respectively. Matrix metalloproteinase 3 was expressed diffusely within the plaques with a fibrofatty histologic pattern. In plaques with foam cell accumulation, matrix metalloproteinase 3 was seen in areas rich in foam cells and the smooth muscle cells near the lumen. In the plaques with fewer macrophages, the proteinase was expressed only in such smooth muscle cells. Matrix metalloproteinase 3 was expressed in the smooth muscle cells in plaques of all histologic types, and macrophages also expressed the metalloproteinase when present in significant numbers. These findings suggest that macrophage accumulation plays an important pathophysiologic role in causing the instability of atherosclerotic lesions by increasing the levels of matrix metalloproteinase 3.

Abnormal elastic system fibers in fibrotic human liver

The network of elastic system fibers in human fibrotic liver was investigated by histological methods, immunohistochemical staining, and electron microscopy. Type III collagen was seen not only in regions of portal fibrosis but also in the sinusoidal wall. However, elastic system fibers were not found in the Disse space of the sinusoidal wall. Elastic system fibers including oxytalan, elaunin, and elastic fibers were found successively in the course of elastogenesis. A few normal oxytalan fibers and abnormal oxytalan fibers were observed in the periportal tracts. Few normal elaunin and abnormal elaunin fibers were observed in regions of portal fibrosis but not in the surrounding margin. Elastic fibers, only in scarce amounts, were observed around the portal veins in the case of chronic active hepatitis but not in acute hepatitis. Abnormal oxytalan fibers were seen as a bundle of wavelike microfibrils and had an irregular arrangement. Abnormal elaunin fibers were not associated with bundles of microfibrils. Abnormal elaunin fibers in large amounts were found interspersed with spiraled collagen, which most likely indicates that the oxytalan fibers degenerated in the course of elastogenesis. Thus, in a fibrotic liver it is possible that synthesis of normal elaunin and elastic fibers does not occur or that the quantity of such fibers synthesized may be small because of the effect of the degenerated oxytalan fibers. As a characteristic of liver fibrosis, the composition of abnormal elastic system fibers and spiraled collagen differs from that in other fibrotic organs.

Novel mutations in the a3 subunit of vacuolar H(+)-adenosine triphosphatase in a Japanese patient with infantile malignant osteopetrosis

A case of infantile malignant osteopetrosis is described. The patient died from respiratory hemorrhage at 7 months of age despite treatment that included high doses of active vitamin D and administration of interferon-gamma. A postmortem examination revealed the presence of many osteoclasts in the bone, which lacked ruffled borders. This observation was consistent with the histology of bone reported in Atp6i-knockout mice, which lack the gene encoding the a3 subunit of vacuolar-type H(+)-adenosine triphosphatase (ATPase). Sequence analysis of the TCIRG1 gene encoding the a3 subunit revealed two novel mutations: a deletion/insertion mutation in exon 9 and a T-to-C transition at the splice donor site of intron 19. The former mutation caused a frame shift and premature stop codon. The latter was associated with abnormal splicing, which was confirmed by sequencing the products amplified by reverse transcription-polymerase chain reaction (RT-PCR), using total RNA from the liver specimen as template. Although several mutations in the TCIRG1 gene in infantile malignant osteopetrosis have been reported in other populations, this is the first case of a Japanese patient with a mutation identified in this gene. These results support the important role of the subunit in the function of the proton pump.

The repeatability of left ventricular volume assessment by a new ambulatory radionuclide monitoring system during head-up tilt

The precise measurement of changes in left ventricular volume is important to elucidate the mechanisms of neurally mediated syncope. This study was conducted to determine whether or not a brand-new ambulatory radionuclide monitoring system (C-VEST system) can be clinically used to easily and precisely measure left ventricular volume and function in tilt testing. To assess the repeatability of the C-VEST system, 12 healthy volunteers (mean age 24+/-4 years old) underwent 20 minute head-up tilt testing and we measured the temporal changes in left ventricular volume and ejection fraction twice a day (first and second studies). To investigate the changes in the C-VEST measurements and the detector position in the first and second studies, tilt testing was performed with an 80-degree passive tilt, which is the same as the standard procedure used in diagnosing neurally mediated syncope. The coefficient of repeatability for both the C-VEST and detector position was well within the clinical range (coefficient of repeatability in left ventricular volume ranged from 1.7 to 2.8; coefficient of repeatability in the detector position ranged from 2.3 to 3.1). Precise evaluation of the left ventricular volume can be achieved by an ambulatory radionuclide monitoring system in tilt testing.

Assessment of left ventricular volume by an ambulatory radionuclide monitoring system during head-up tilt in patients with unexplained syncope: relation to autonomic activity assessed by heart rate variability

BACKGROUND

Decreased left ventricular volume during head-up tilt plays an important role in triggering syncope in patients with neurally mediated syncope. However, precise changes in left ventricular volume during head-up tilt have not been well investigated. This study was conducted to test the hypothesis that the decline in left ventricular volume during tilt could trigger ventricular mechanoreceptor activation.

METHODS AND RESULTS

To investigate the mechanisms of tilt-induced syncope, we measured the temporal changes in left ventricular volume, ejection fraction, cardiac output, and heart rate variability indices during head-up tilt in 25 patients with syncope of undetermined etiology. Eleven patients had a cardioinhibitory response (CI group), 7 patients showed a vasodepressor response (VD group), and 7 patients demonstrated a negative response (NG group). Before syncope, ejection fraction increased most in the CI group, the left ventricular end-diastolic volume declined most in the VD group (VD group, -11.0% +/- 3.3%; CI group, -2.8% +/- 4.8%; NG group, -3.4% +/- 2.2%; P <.005), and the high-frequency spectra increased most in the CI group (CI group, 25.0% +/- 21.0%; VD group, -4.1% +/- 11.7%; NG group, -5.3% +/- 12.7%; P <.01). The vasodepressor response was dependent on left ventricular volume, whereas the cardioinhibitory response was related to the vagal activity reflected by high-frequency spectra.

CONCLUSIONS

The precise evaluation of left ventricular volume by an ambulatory radionuclide monitoring system combined with a heart rate variability analysis is considered useful for clarifying the pathophysiology of neurally mediated syncope.

Different mechanisms of isoproterenol-induced and nitroglycerin-induced syncope during head-up tilt in patients with unexplained syncope: important role of epinephrine in nitroglycerin-induced syncope

INTRODUCTION

A reduction in left ventricular volume and an increase in epinephrine levels have been reported in tilt-induced neurally mediated syncope. To compare the mechanisms of isoproterenol-induced and nitroglycerin-induced syncope during head-up tilt and to investigate the role of catecholamines, the temporal changes in plasma levels of norepinephrine and epinephrine and in left ventricular volume were measured.

METHODS AND RESULTS

The first study population consisted of 90 patients with syncope of unknown etiology and 12 control subjects. The second study population consisted of 43 patients with unexplained syncope. In the first study, head-up tilt (80 degree angle) was conducted for 40 minutes, and norepinephrine and epinephrine levels were measured. In the second study, all patients were randomly allocated to either isoproterenol test (20 patients) or nitroglycerin test (23 patients) for 20-minute head-up tilt. Isoproterenol infusion was given at a rate of 1 to 3 microg/min. Intravenous infusion of nitroglycerin was started at 250 microg/hour with increasing dosages up to 1,500 microg/hour. Norepinephrine and epinephrine were measured in peripheral venous blood. Left ventricular volumes were measured by echocardiography with patients in the supine position and during head-up tilt every 1 minute. End-diastolic volume and end-systolic volume were calculated. In the first study, 61 patients demonstrated a positive response and 29 patients demonstrated a negative response. Plasma norepinephrine changes during head-up tilt were not significantly different, whereas epinephrine levels were significantly higher in the positive patients than in the negative and control subjects (148 +/- 118 pg/mL vs 66 +/- 31 pg/mL and 55 +/- 27 pg/mL). Thirteen of the 20 patients given isoproterenol and 15 of the 23 patients given nitroglycerin showed a positive head-up tilt (65.0% vs 65.2%; P = NS). During isoproterenol and nitroglycerin infusion head-up tilt, epinephrine in the positive group determined by the nitroglycerin test was significantly higher than that in the other three groups (103 +/- 38 pg/mL vs 60 +/- 33 pg/mL, 31 +/- 21 pg/mL, and 50 +/- 52 pg/mL). In contrast, end-systolic volume was significantly smaller in the positive group than in the other three groups based on findings of the isoproterenol test.

CONCLUSION

The findings suggest that nitroglycerin triggers head-up tilt-induced syncope by increasing epinephrine levels, whereas isoproterenol induces syncope by decreasing left ventricular volume.

New thermo-couple copper constantan catheter for measuring regional coronary blood flow and evaluating metabolism

A new thermodilution catheter with a thermo-couple copper constantan and latex balloon in the tip has recently been developed. This device has two orifices. The left anterior descending (LAD) and/or left circumflex (LCX) flows were measured using a Doppler flow wire. The correlation between the LAD and GCV flow as well as between the LCX and CS-GCV flow were studied in closed chest animals. The flow distributions were evaluated by colored microspheres that were infused into the LAD and LCX. The regional lactate extraction ratio was measured by GCV and/or CS blood sampling performed either with or without balloon inflation before and during pacing in either LAD or LCX occluded animals. The correlations between the LAD and GCV flow, as well as between the LCX and CS-GCV flow were significant (r=0.96, r=0.93, n=30, p<0.001). The flow distribution by color microspheres in the GCV was 75+/-10% for the LAD, whereas in CS it was 70+/-12% for the LCX. By pacing, the lactate extraction ratio of the drained blood from the ischemic myocardium was +10+/-3% in the GCV blood, whereas it was -10+/-4% (p<0.01) in the CS blood. Thus, this new thermodilution catheter with a balloon was found to be useful for measuring regional coronary hemodynamics and also for evaluating the regional myocardial metabolism.

Establishment and characterization of chondrocyte cell lines from the costal cartilage of SV40 large T antigen transgenic mice

Complete understanding of the physiology and pathology of the cartilage is essential to establish treatments for a variety of cartilage disorders and defects such as rheumatoid arthritis, congenital malformations, and tumors of cartilage. Although synthetic materials have been used in many cases, they possess inherent problems including wear of the materials and low mechanical strength. Autograft has been considered very effective to overcome these problems. However, the limitation of the transplant volume is a major problem in autograft to be overcome. The costal cartilage is the most serious candidate for donor site transplantation, since it is the largest permanent hyaline cartilage in the body. To investigate the possibility using the costal cartilage as a transplant source, we have established and characterized three mouse chondrocyte cell lines (MCC-2, MCC-5, and MCC-35) derived from the costal cartilage of 8-week-old male SV40 large T-antigen transgenic mice. At confluence, all the cell lines formed nodules that could be positively stained with alcian blue (pH 2.5). The size of nodules gradually increased during culturing time. After 2 and 6 weeks of culture, RT-PCR analysis demonstrated that all three cell lines expressed mRNA from the cartilage-specific genes for type II collagen, type XI collagen, aggrecan, and link protein. Furthermore, type X collagen expression was detected in MCC-5 and MCC-35 but not in MCC-2. Any phenotypic changes were not observed over 31 cell divisions. Immunocytochemistry showed further that MCC-2, MCC-5, and MCC-35 produced cartilage-specific proteins type II collagen and type XI collagen, while in addition MCC-5 and MCC-35 produced type X collagen. Treatment with 1alpha, 25-dihydroxyvitamin D(3) inhibited cell proliferation and differentiation of the three cell lines in a dose-dependent manner. These phenotypic characteristics have been found consistent with chondrocyte cell lines established from cartilage tissues other than costal cartilage. In conclusion, costal cartilage shows phenotypic similarities to other cartilages, i.e., articular cartilage and embryonic limbs, suggesting that costal cartilage may be very useful as the donor transplantation site for the treatment of cartilage disorders. Furthermore, the cell lines established in this study are also beneficial in basic research of cartilage physiology and pathology.

Circulating skeletal stem cells

We report the isolation of adherent, clonogenic, fibroblast-like cells with osteogenic and adipogenic potential from the blood of four mammalian species. These cells phenotypically resemble but are distinguishable from skeletal stem cells found in bone marrow (stromal stem cells, "mesenchymal stem cells"). The osteogenic potential of the blood-borne cells was proven by an in vivo transplantation assay in which either polyclonal or single colony-derived strains were transplanted into the subcutis of immunocompromised mice, and the donor origin of the fully differentiated bone cells was proven using species-specific probes. This is the first definitive proof of the existence of circulating skeletal stem cells in mammals.

Bone formation by transplanted human osteoblasts cultured within collagen sponge with dexamethasone in vitro

To apply osteoblasts to bone reconstruction, we proved that transplanted osteoblasts possessed the differentiated osteoblastic function and formed bonelike tissue in vivo after transplantation. First, we confirmed that dexamethasone (Dex) promoted the expression of osteoblastic phenotype in human osteoblast culture using reverse-transcription-polymerase chain reaction (RT-PCR). These osteoblasts were cultured for 10 days within collagen sponge, which consists of denatured type I collagen, in the presence or absence of 10(-7) M Dex. The osteoblasts along with collagen sponge were transplanted into the trapezius muscles of 8-week-old severe combined immunodeficiency (SCID) mice, and the transplants were harvested at 2, 4, 6, and 8 weeks. At 2 weeks, Dex-treated osteoblasts formed bonelike tissue, the quantity of which increased in a time-dependent manner to 8 weeks. This bonelike tissue was composed of mineralized collagen matrix newly synthesized by the transplanted osteoblasts. This mineralized matrix was separated from the osteoblasts by nonmineralized matrixlike osteoid. Furthermore, many osteocytic cells were observed in this mineralized matrix. A high expression of alkaline phosphatase (ALPase) and osteocalcin was detected in the transplanted cells surrounding the bonelike tissue. In situ hybridization for human-specific alu sequence indicated that newly formed bone was of donor origin. The transplants of nontreated cells failed to form bonelike tissue. The transplants of collagen sponge alone formed no bonelike tissue. These studies indicate that Dex-treated human osteoblasts possess the differentiated osteoblastic function and are able to form bone tissue in vivo. These new findings are of use in facilitating the application of osteoblasts to bone reconstruction.

Pedicled bone flap formation using transplanted bone marrow stromal cells

HYPOTHESIS

Transplanted osteoprogenitor cells derived from cultured bone marrow stromal cells (BMSCs) can be used to fabricate pedicled bone flaps.

DESIGN

Prospective, randomized experimental trials.

SETTING

Basic science research laboratory.

MATERIALS

Immunodeficient female NIH-Bg-Nu-Xid mice, aged 3 months.

INTERVENTION

The BMSCs were harvested from the long bones of C57Bl/6 transgenic mice carrying the type Ialpha1 collagen-chloramphenicol acetyl transferase reporter gene construct; their numbers were expanded in tissue culture. Treated mice received BMSC transplantations around the common carotid artery and internal jugular vein, the aorta and its venae comitantes, or the saphenous artery and vein; control mice received a sham transplant in comparable recipient sites.

MAIN OUTCOME MEASURES

Mice underwent harvesting from 4 weeks to 2 years after transplantation. Transplants were evaluated via histological, immunohistochemical, and angiographic analyses.

RESULTS

Compared with the controls, which formed no bone, 32 of 37 BMSC-containing transplants formed a vascularized bone island that was perfused specifically and solely by its common carotid artery vascular source. Mature transplants consisted of well-developed lamellar, corticocancellous bone whose osteocytes were derived from the grafted BMSCs; hematopoietic tissue derived from the recipient mouse. Transplants formed as early as 4 weeks and remained stable in size as late as 108 weeks.

CONCLUSIONS

Bone marrow stromal cells can be used to create vascularized bone flaps in mice; these bone constructs are vascularized by their pedicle and therefore can potentially be transferred to a recipient site using microsurgical techniques. These findings provide proof of principle of an additional clinical application of BMSC transplantation techniques.

Expression of telomerase components in oral keratinocytes and squamous cell carcinomas

Telomerase activity was measured using a telomeric repeat amplification protocol (TRAP), and expressions of the telomerase components, telomerase associated protein 1 (hTEP1), human telomerase RNA component (hTR), and human telomerase reverse transcriptase (hTERT) were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) in cultured normal oral keratinocytes and oral squamous cell carcinoma (SCC) cells. Telomerase localization was analyzed by in situ hybridization (ISH) in normal, precancerous and cancerous oral tissues. There was a strong correlation of telomerase activity with the expression levels of hTERT but not with hTEP1 or hTR mRNA in the cultured cells. Not only hTEP1 and hTR but also hTERT expression were detected in the basal cells of normal oral mucosa, and the cells expressing these mRNAs were also seen in the upper layer of leukoplakia of gingiva, and a heterogeneous pattern of expression was observed in the oral SCC tissues. These results indicate that there are at least two steps in the increase of telomerase activity during carcinogenesis in oral squamous cells; a change in distribution of cells expressing these telomerase components and the over-expression of hTERT gene in individual cells.

Sequence-based diagnosis of tyrosinase-related oculocutaneous albinism: successful sequence analysis of the tyrosinase gene from blood spots dried on filter paper

BACKGROUND

A large number of mutations of the tyrosinase gene result in oculocutaneous albinism (OCA). Therefore, at present, sequence analysis of the tyrosinase gene has become necessary to diagnose OCA patients and their relatives.

OBJECTIVE

The aim of this study was to facilitate the sequence-based diagnosis of tyrosinase-related OCA by using small amounts of the patient's blood.

METHODS

Blood spots dried on filter papers were used as sources of genomic DNA. The exons and flanking regions of the tyrosinase gene were amplified by polymerase chain reaction (PCR) and were directly sequenced in both directions.

RESULTS

We successfully amplified all exons of the tyrosinase gene by PCR and were able to characterize compound heterozygous mutations of R278X and + delta C310 in the patient's gene.

CONCLUSION

Recent advances of PCR-related technology allowed us to use fairly limited samples of blood for sequence analysis of the tyrosinase gene.

Effects of SSM (specific substance maruyama) on HBe antigen-positive chronic hepatitis B -clinical efficacy and modulation of cytokines

Twenty-three patients with HBe antigen-positive chronic hepatitis B were treated with capitalite first letters Maruyama (SSM). HBe antigen turned negative in 15 patients. The levels of various cytokines in pre- and post-treatment frozen serum samples from six patients whose HBe antigen turned negative and from five whose HBe antigen did not were examined. Reduction of serum interleukin (IL) -10 level to below 20 pg/ml was observed after SSM treatment in four of the six patients whose HBe antigen turned negative. SSM was found to stimulate the production of interferon (IFN) -gamma in peripheral blood cells from two healthy volunteers. This stimulatory effect was confirmed in 12 out of 24 healthy volunteers. SSM augmented the production of IFN-gamma in eight out of 10 patients with chronic hepatitis B and nine of 10 with hepatitis C. These results demonstrate for the first time that SSM stimulates the production of IFN-gamma in human peripheral blood cells and also suggest that treatment of HBe antigen-positive chronic hepatitis B patients with SSM leads to the clearance of HBe antigen and normalization of serum aspartate aminotransferase levels through inhibition of IL-10 and stimulation of IFN-gamma.

Osteogenic imprinting upstream of marrow stromal cell differentiation

Five spontaneously transformed cell lines were established from a population of murine bone marrow stromal cells (BMSCs) and the expression profiles of phenotype-characteristic genes, patterns of in vitro differentiation, and osteogenic capacity after in vivo transplantation were determined for each. All the clones expressed stable levels of cbfa1, the osteogenic "master" gene, whereas the levels of individual phenotypic mRNAs were variable within each, suggestive of both maturational and phenotypic plasticity in vitro. Varying levels of collagen type I and alkaline phosphatase (AP) were expressed in all the clonal lines. The clonal lines with proven in vivo osteogenic potential (3 out of 5) had a high proliferation rate and expressed bone sialoprotein (BSP), whereas the two nonosteogenic clones proliferated more slowly and never expressed BSP. Bone nodules were only observed in 2 out of 3 of the osteogenic lines, and only 1 out of three formed cartilage-like matrix in vitro. There was no evidence of chondrogenesis in the nonosteogenic lines. By contrast, LPL was expressed in two osteogenic and in two nonosteogenic lines. These results demonstrate the presence of multipotential and restricted progenitors in the murine stromal system. cbfa1, collagen type I, and AP expression were common to all, and therefore presumably early, basic traits of stromal cell lines that otherwise significantly differ with respect to growth and differentiation potential. This finding suggests that an osteogenic imprinting lies upstream of diversification, modulation, and restriction of stromal cell differentiation potential.

Increased serum IL-10 and endothelin levels in hemolytic uremic syndrome caused by Escherichia coli O157

BACKGROUND

Shiga toxin, produced by Escherichia coli O157:H7, is important for the pathogenicity of the epidemic form of hemolytic uremic syndrome (HUS). This toxin has recently been found to stimulate endothelin-1 synthesis in cultured endothelial cells in vitro.

METHODS

We investigated endothelin and cytokine levels in sera during a large outbreak of E. coli O157:H7 infection in Osaka, Japan, in 1996. Eleven patients with HUS and 9 patients with hemorrhagic colitis at the onset of E. coli O157:H7 infection were studied.

RESULTS

Serum IL-6 (p < 0.01), IL-8 (p < 0.05), IL-10 (p < 0.001) and endothelin (p < 0.001) levels were significantly increased in patients with HUS compared to those with colitis only. The serum thrombomodulin level, a molecular marker of endothelial damage, also showed a significant positive correlation with serum IL-6 (p < 0.01), IL-8 (p < 0.01), IL-10 (p < 0.01) and endothelin (p < 0.001) levels. In a HUS patient, the increase in serum IL-10 and endothelin levels reached a plateau prior to the peak of serum creatinine levels.

CONCLUSION

Increased serum endothelin synthesis by Shiga toxin in vivo was proven in HUS secondary to E. coli O157:H7 infection. Increased serum endothelin and IL-10 levels were speculated to be associated with the development of HUS through vascular endothelial damage caused by E. coli O157:H7 infection.

The cell cycle control gene ZAC/PLAGL1 is imprinted--a strong candidate gene for transient neonatal diabetes

We describe a screen for new imprinted human genes, and the identification in this way of ZAC (zinc finger protein which regulates apoptosis and cell cycle arrest)/ PLAGL1 (pleomorphicadenoma of the salivary gland gene like 1) as a strong candidate gene for transient neonatal diabetes mellitus (TNDM). To screen for imprinted genes, we compared parthenogenetic DNA from the chimeric patient FD and androgenetic DNA from hydatidiform mole, using restriction landmark genome scanning for methylation. This resulted in identification of two novel imprinted loci, one of which (NV149) we mapped to the TNDM region of 6q24. From analysis of the corresponding genomic region, it was determined that NV149 lies approximately 60 kb upstream of the ZAC / PLAGL1 gene. RT-PCR analysis was used to confirm that this ZAC / PLAGL1 is expressed only from the paternal allele in a variety of tissues. TNDM is known to result from upregulation of a paternally expressed gene on chromosome 6q24. The paternal expression, map position and known biological properties of ZAC / PLAGL1 make it highly likely that it is the TNDM gene. In particular, ZAC / PLAGL1 is a transcriptional regulator of the type 1 receptor for pituitary adenylate cyclase-activating polypeptide, which is the most potent known insulin secretagog and an important mediator of autocrine control of insulin secretion in the pancreatic islet.

Initiation of ectopic epithelial calcification in a calcifying odontogenic cyst

Ultrastructural observation was performed on a calcifying odontogenic cyst (COC) associated with an odontoma and arising in the right mandibular region of an 8-year-old Japanese boy. Four types of cells were identified in the epithelial layer of the COC. The basal cells were low columnar in shape and contained some intracellular organelles. They were attached to the neighboring cells with a few desmosomes and resembled inner enamel epithelium of the normal enamel organ. The stellate reticulum-like cells, polygonal in shape, possessed desmosomes and many cytoplasmic projections. Some intracellular organelles and a few bundles of tonofilaments were observed in the cytoplasm. The light oval cells that were pale staining with toluidine blue contained dilated membranous organelles and many relatively evenly distributed tonofilaments. These cells were usually scattered in the vicinity of the focal accumulations of ghost cells, and the cell membrane was discontinuous in parts. The ghost cells contained many bundles of tonofilaments that were 60-240 nm in diameter and arranged in various directions. No intact intracellular organelles were noted in the cytoplasm. They were attached to the neighboring ghost cells with some desmosomes and their cell membrane was discontinuous in parts. A variety of vesicles, 90-450 nm in diameter, were scattered among the tonofilament bundles. Some of these contained needle-like crystals that were considered to be initial calcification sites in ghost cells. These vesicles presented morphological similarities to matrix vesicles, and it is therefore suggested that matrix vesicle-like structures are deeply involved with initiation of calcification of ghost cells in COC.

Expression pattern of macrophage migration inhibitory factor during embryogenesis

Although macrophage migration inhibitory factor (MIF) was originally identified as a lymphokine that inhibits the migration of macrophages, its ubiquitous expression suggests it may have a role beyond the immune system. Here we report a detailed characterization of MIF expression during mouse embryogenesis. The MIF expression pattern was found to parallel tissues specification and organogenesis.

Changes in the proliferative activities of cells in experimental atherosclerotic plaques during remodeling

To investigate the relationship between cytologic alterations and cellular proliferation during atherosclerotic remodeling, we examined experimental atheromatous plaques by immunohistochemistry. Plaques were formed on rabbit aortas by cholesterol-enriched diets and mechanical stimulation over a period of 2 months. Plaques were examined 1 month and 6 months after induction. We used antibodies RAM-11, HHF-35, and monoclonal anti-proliferating cell nuclear antigen (PCNA) antibody for detection of macrophages (Mphi), smooth muscle cells (SMC), and PCNA, respectively. One month after induction, the plaques revealed a thickened intima with a fibrofatty histologic pattern or accumulation of foam cells. With either histologic pattern, foam cells were found to be Mphi and proliferative activity was mainly observed in Mphi. Six months after induction, calcification and organization were seen on the induced plaques, suggesting progression of remodeling. There were fewer Mphi and more SMC compared with plaques examined 1 month after induction. Proliferative activity was observed mainly in SMC. We have demonstrated that the proliferative activity of cell types changes during remodeling of atheromatous plaques. Our results suggest an important relationship between the proliferative activity of SMC and remodeling.

Thy-1 antigen expression by cells in the osteoblast lineage

Identification of surface markers involved in osteoblast differentiation provides a method to isolate osteoblasts at various stages of maturation. In this study, we examined expression of the T lymphocyte differentiation antigen, Thy-1, by osteoblastic cells from different species. Murine skeletal progenitor, neonatal calvarial, and adult bone cells (ABCs) were selected to represent osteoblasts at distinct stages of maturation. Flow cytometric analysis showed that Thy-1 expression was undetectable on the progenitor cells (mouse limb bud clones 14 and 17), appeared on calvarial cells (45%+), and was decreased on ABCs (< 10%+). Thy-1 was also detected in situ on osteoblastic cells in mouse calvariae. Thy-1 mRNA expression correlated with cell surface expression. Antigen expression was markedly increased during the cells' proliferative phase in culture. Furthermore, examination of primary rat and human osteoblast-like cells revealed that significant levels of Thy-1 were also expressed on those cells derived from subconfluent culture. This study indicates that osteoblasts express Thy-1 antigen and that its expression is maximal at their earliest stage of maturation, during the proliferative phase, and then declines as the cells mature. In a role similar to the one it plays in the hematopoietic system, Thy-1 antigen may be useful as a differentiation marker in following the development of the osteoblast.

Expression of E-cadherin in oral cancer cell lines and its relationship to invasiveness in SCID mice in vivo

We examined the expression of E-cadherin in nine oral cancer cell lines. HSC-4, NA, ZA, HOC927 and Ca9-22 cells strongly expressed E-cadherin [E-CD(++) cell line] and HSC-2 and HSC-3 cells weakly expressed E-cadherin [E-CD(+) cell line]. All the cell lines that expressed E-cadherin were of cuboidal morphology and formed cobblestone colonies. In contrast, TSU and HOC313 cells had spindle shapes, formed dispersed colonies, and were completely negative for E-cadherin [E-CD(-) cell line]. Moreover, all cell lines that expressed E-cadherin showed tumorgenicity in SCID mice, but E-CD(-) cell lines did not show tumorgenicity. The tumors derived from E-CD(+) cell lines invaded deeper into the connective tissues than those from E-CD(++) cell lines. In immunohistochemical analysis, the difference was more marked at the edges of the cancer nests. These results suggest that E-cadherin expression was relevant to the cell forms and the differential grade of cultured cells and that reduced E-cadherin in oral cancer may be associated with invasiveness in vivo.

Construction and in vivo efficacy of a replication-deficient recombinant adenovirus encoding murine growth hormone

We have constructed a recombinant, replication-deficient, first-generation adenovirus-encoding mouse GH (mGH), AdCMVmGH. This virus directed mGH production from an epithelial cell line in vitro in a dose-dependent manner. When injected into the quadriceps muscle or submandibular ducts of mGH-deficient Snell dwarf mice, AdCMVmGH resulted in the production of significantly elevated serum mGH levels. Furthermore, after i.m. injection, dwarf mice increased in weight by 8% over 4 days and close to 100% by 30 days. When AdCMVmGH was administered to 3- to 4-week-old rats by i.v. injection to assess general metabolic responses, serum mGH, insulin-like growth factor 1, triglycerides and cholesterol levels were significantly elevated. AdCMVmGH should be a valuable experimental tool for the controlled, directed expression of mGH in preclinical mouse model studies.

Endothelium-dependent flow-mediated vasodilation in coronary and brachial arteries in suspected coronary artery disease

Previous studies showed a weak correlation between endothelial function of the coronary arteries as assessed by acetylcholine and brachial artery vasomotion during reactive hyperemia. When the same stimulus was used, we obtained a strong correlation between flow-mediated dilation in the coronary and brachial arteries (r=0.78, p <0.001), so that noninvasive assessment of flow-mediated dilation in the brachial artery could be used as a surrogate measure for coronary artery endothelial function.

Receptor tyrosine kinase expression in human bone marrow stromal cells

Bone marrow stromal cells (BMSCs) are a heterogeneous population of cells derived from colony-forming units-fibroblastic (CFU-Fs). These cells reside in the bone marrow cavity and are capable of differentiating into several cell phenotypes including osteoblasts, chondroblasts, hematopoiesis-supporting stromal cells, and adipocytes. However, the factors that regulate the proliferation and differentiation of the BMSC population are for the most part unknown. Since many members of the receptor tyrosine kinase (RTK) family have been shown to participate in growth control of various mesenchymal cell populations, in this study we examined the expression and function of RTKs in the BMSC population. Degenerate oligonucleotides corresponding to two conserved catalytic domains of the RTK family and RT-PCR were used initially to determine which RTKs are expressed in the human BMSC (hBMSC) system. After subcloning the amplification product generated from mRNA of a multicolony-derived hBMSC strain, PDGF receptor (beta), EGF receptor, FGF receptor 1, and Axl were identified by DNA sequencing of 26 bacterial colonies. Furthermore, PDGF and EGF were found to enhance BMSC growth in a dose-dependent manner and to induce tyrosine phosphorylation of intracellular molecules, including the PDGF and EGF receptors themselves, demonstrating the functionality of these receptors. On the other hand, bFGF was found to have little effect on proliferation or tyrosine phosphorylation. Since single colony-derived hBMSC strains are known to vary from one colony to another in colony habit (growth rate and colony structure) and the ability to form bone in vivo, the expression levels of these RTKs were determined in 18 hBMSC clonal strains by semiquantitative RT-PCR and were found to vary from one clonal strain to another. While not absolutely predictive of the osteogenic capacity of individual clonal strains, on average, relatively high levels of PDGF-receptor were found in bone-forming strains, while on average, nonbone-forming strains had relatively high levels of EGF-receptor. Taken together, these results indicate that RTKs play a role in the control of hBMSC proliferation, and that the differential pattern of RTK expression may be useful in correlating the biochemical properties of individual clonal strains with their ability to produce bone in vivo.

Repair of craniotomy defects using bone marrow stromal cells

BACKGROUND

Techniques used to repair craniofacial skeletal defects parallel the accepted surgical therapies for bone loss elsewhere in the skeleton and include the use of autogenous bone and alloplastic materials. Transplantation of a bone marrow stromal cell population that contains osteogenic progenitor cells may be an additional modality for the generation of new bone.

METHODS

Full thickness osseous defects (5 mm) were prepared in the cranium of immunocompromised mice and were treated with gelatin sponges containing murine alloplastic bone marrow stromal cells derived from transgenic mice carrying a type I collagen-chloramphenicol acetyltransferase reporter gene to follow the fate of the transplanted cells. Control surgical sites were treated with spleen stromal cells or gelatin sponges alone, or were left untreated. The surgical defects were analyzed histologically for percent closure of the defect at 2, 3, 4, 6, and 12 weeks.

RESULTS

Cultured bone marrow stromal cells transplanted within gelatin sponges resulted in osteogenesis that repaired greater than 99.0+/-2.20% of the original surgical defect within 2 weeks. In contrast, cranial defects treated with splenic fibroblasts, vehicle alone, or sham-operated controls resulted in minimal repair that was limited to the surgical margins. Bone marrow stromal cells carrying the collagen transgene were immunodetected only in the newly formed bone and thus confirmed the donor origin of the transplanted cells.

CONCLUSIONS

These studies demonstrate that mitotically expanded bone marrow cells can serve as an abundant source of osteoprogenitor cells that are capable of repairing craniofacial skeletal defects in mice without the addition of growth or morphogenetic factors.