Genetic evidence for involvement of β2-adrenergic receptor in brown adipose tissue thermogenesis in humans

BACKGROUND

Sympathetic activation of brown adipose tissue (BAT) thermogenesis can ameliorate obesity and related metabolic abnormalities. However, crucial subtypes of the β-adrenergic receptor (AR), as well as effects of its genetic variants on functions of BAT, remains unclear in humans. We conducted association analyses of genes encoding β-ARs and BAT activity in human adults.

METHODS

Single nucleotide polymorphisms (SNPs) in β1-, β2-, and β3-AR genes (ADRB1, ADRB2, and ADRB3) were tested for the association with BAT activity under mild cold exposure (19 °C, 2 h) in 399 healthy Japanese adults. BAT activity was measured using fluorodeoxyglucose-positron emission tomography and computed tomography (FDG-PET/CT). To validate the results, we assessed the effects of SNPs in the two independent populations comprising 277 healthy East Asian adults using near-infrared time-resolved spectroscopy (NIRTRS) or infrared thermography (IRT). Effects of SNPs on physiological responses to intensive cold exposure were tested in 42 healthy Japanese adult males using an artificial climate chamber.

RESULTS

We found a significant association between a functional SNP (rs1042718) in ADRB2 and BAT activity assessed with FDG-PET/CT (p < 0.001). This SNP also showed an association with cold-induced thermogenesis in the population subset. Furthermore, the association was replicated in the two other independent populations; BAT activity was evaluated by NIRTRS or IRT (p < 0.05). This SNP did not show associations with oxygen consumption and cold-induced thermogenesis under intensive cold exposure, suggesting the irrelevance of shivering thermogenesis. The SNPs of ADRB1 and ADRB3 were not associated with these BAT-related traits.

CONCLUSIONS

The present study supports the importance of β2-AR in the sympathetic regulation of BAT thermogenesis in humans. The present collection of DNA samples is the largest to which information on the donor's BAT activity has been assigned and can serve as a reference for further in-depth understanding of human BAT function.

Changes in Optical Path Length Reveal Significant Potential Errors of Muscle Oxygenation Evaluation during Exercise in Humans

PURPOSE

Near-infrared spectroscopy (NIRS), performed with a commonly available noninvasive tissue oxygenation monitoring device, is based on the modified Beer-Lambert law (MBLL). Although NIRS based on MBLL (NIRSMBLL) assumes that the optical path length (PL) is constant, the effects of changes in PL during exercise on muscle oxygenation calculated by MBLL are still incompletely understood. Thus, the purposes of this study were to examine the changes in optical properties during ramp incremental exercise and to compare muscle oxygen dynamics measured by time-resolved NIRS with those calculated based on MBLL.

METHODS

Twenty-two healthy young men performed ramp incremental cycling exercise until exhaustion. Optical properties (reduced scattering coefficient and PL) and absolute oxygenated, deoxygenated, and total hemoglobin and myoglobin concentrations (oxy[Hb + Mb], deoxy[Hb + Mb], and total[Hb + Mb], respectively) at the vastus lateralis were continuously monitored by a three-wavelength (763, 801, and 836) time-resolved NIRS device. The values of oxy-, deoxy-, and total[Hb + Mb] were then recalculated by assuming constant PL.

RESULTS

PL at all wavelengths statistically significantly shortened during exercise. In particular, PL at 763 nm was greatly shortened, and the average changes during exercise were a 9.8% ± 3.1% reduction. In addition, significant differences in the kinetics of oxy-, deoxy-, and total[Hb + Mb] between directly measuring PL and assuming constant PL were found. The average changes in measured PL and assuming constant PL-deoxy[Hb + Mb] were increases of 28.8 ± 16.0 μM and increases of 16.4 ± 9.3 μM, respectively.

CONCLUSION

Assuming constant PL in NIRSMBLL significantly underestimated actual muscle oxy/deoxygenation as compared with measurements obtained by real-time PL determination. The percent degree of the underestimated oxy/deoxygenation was greater than the percent degree of the changes in PL.

Reduced Scattering Coefficient During Incremental Exercise Is Constant Without Being Affected by Changes in Muscle Oxygenation or Hemodynamics

Previous studies have reported that the reduced scattering coefficient (μ_s') in the vastus lateralis changes during ramp-incremental exercise due to blood volume changes or accumulation of metabolic by-products. We aimed to clarify the influences of deoxygenation and blood volume changes during exercise on μ_s' dynamics in subjects with various aerobic capacities. Twenty-three healthy young men participated in this study. All subjects performed a ramp-incremental cycling exercise until exhaustion and were divided into two groups: lower (Low: n = 12; peak pulmonary oxygen uptake per kg of fat-free mass (VO_2peak), 54.2 ± 5.3 mL/kg/min) and higher aerobic capacity group (High: n = 11; VO_2peak, 69.7 ± 5.2 mL/kg/min) by median of VO_2peak. Deoxygenated hemoglobin and myoglobin concentrations (deoxy[Hb + Mb]) and total [Hb + Mb] (total[Hb + Mb]) in the vastus lateralis were monitored during the exercise by three-wavelength (760, 800, and 830 nm) time-resolved NIRS. Similarly, μ_s' at each wavelength was continuously monitored. With increasing exercise intensity, deoxy[Hb + Mb] and total[Hb + Mb] significantly increased in both groups, and the average values of the peak amplitudes of deoxy[Hb + Mb] and total[Hb + Mb] during exercise showed a 106.4% increase and a 17.9% increase from the start of the exercise, respectively. Furthermore, the peak amplitude of total[Hb + Mb] was significantly greater in High. Conversely, there were no changes in μ_s' at any wavelength during exercise and no differences between two groups, suggesting that the great deoxygenation and blood volume changes during incremental exercise have little effect on μ_s' dynamics.

Effects of Exercise Training on Cardiac and Skeletal Muscle Functions in Patients with Chronic Heart Failure

The primary symptom in patients with chronic heart failure (CHF) is exercise intolerance. Previous studies have reported that reduced exercise tolerance in CHF can be explained not only by cardiac output (a central factor) but also by reduced skeletal muscle aerobic capacity (a peripheral factor). Although exercise training in CHF improves exercise tolerance, few studies have evaluated the effects of exercise training on each specific central and peripheral factor in CHF. The aim of this study was to investigate the central and peripheral aerobic functions in CHF and the effects of exercise training in CHF on cardiac output and skeletal muscle deoxygenation during exercise. We assessed peak oxygen uptake (VO₂) during cardiopulmonary exercise testing, peak cardiac output (CO) using noninvasive hemodynamic monitoring, and muscle oxygen saturation (SmO₂) using near-infrared spectroscopy (NIRS). Patients with CHF were trained for 12 weeks and performed ramp cycling exercise until exhaustion before and after the exercise training. Peak VO₂, peak CO, and SmO₂ changes from rest to peak exercise (ΔSmO₂) were significantly lower in CHF than those in healthy subjects. As a result of exercise training, peak oxygen uptake in patients with CHF was improved and positively associated with change in ΔSmO₂. In contrast, there was no change in peak cardiac output. The results of this study indicate that both cardiac and skeletal muscle functions in patients with CHF were lower than those in healthy subjects. Further, the results suggest that the improvement of exercise capacity in patients with CHF by exercise training was related to the improved utilization of oxygen (a peripheral factor) in skeletal muscle.

Vigorous-Intensity Physical Activities Are Associated with High Brown Adipose Tissue Density in Humans

Brown adipose tissue (BAT) plays a role in adaptive thermogenesis in response to cold environments and dietary intake via sympathetic nervous system (SNS) activation. It is unclear whether physical activity increases BAT density (BAT-d). Two-hundred ninety-eight participants (age: 41.2 ± 12.1 (mean ± standard deviation), height: 163.6 ± 8.3 cm, weight: 60.2 ± 11.0 kg, body mass index (BMI): 22.4 ± 3.0 kg/m², body fat percentage: 25.4 ± 7.5%) without smoking habits were categorized based on their physical activity levels (a group performing physical activities including walking and moderate physical activity (WM) and a group performing WM + vigorous-intensity physical activities (VWM)). We measured the total hemoglobin concentration ([Total-Hb]) in the supraclavicular region, an index of BAT-d, and anthropometric parameters. [Total-Hb] was significantly higher in VWM than WM for all participant groups presumably owing to SNS activation during vigorous-intensity physical activities, and unrelated to the amount of total physical activity levels. Furthermore, multiple regression analysis revealed that BAT-d was related to visceral fat area and VWM in men and related to body fat percentage in women. We conclude that vigorous-intensity physical activities are associated with high BAT-d in humans, especially in men.

Near-Infrared Time-Resolved Spectroscopy for Assessing Brown Adipose Tissue Density in Humans: A Review

Brown adipose tissue (BAT) mediates adaptive thermogenesis upon food intake and cold exposure, thus potentially contributing to the prevention of lifestyle-related diseases. ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) with computed tomography (CT) (¹⁸FDG-PET/CT) is a standard method for assessing BAT activity and volume in humans. ¹⁸FDG-PET/CT has several limitations, including high device cost and ionizing radiation and acute cold exposure necessary to maximally stimulate BAT activity. In contrast, near-infrared spectroscopy (NIRS) has been used for measuring changes in O₂-dependent light absorption in the tissue in a non-invasive manner, without using radiation. Among NIRS, time-resolved NIRS (NIR_TRS) can quantify the concentrations of oxygenated and deoxygenated hemoglobin ([oxy-Hb] and [deoxy-Hb], respectively) by emitting ultrashort (100 ps) light pulses and counts photons, which are scattered and absorbed in the tissue. The basis for assessing BAT density (BAT-d) using NIR_TRS is that the vascular density in the supraclavicular region, as estimated using Hb concentration, is higher in BAT than in white adipose tissue. In contrast, relatively low-cost continuous wavelength NIRS (NIR_CWS) is employed for measuring relative changes in oxygenation in tissues. In this review, we provide evidence for the validity of NIR_TRS and NIR_CWS in estimating human BAT characteristics. The indicators (Ind_NIRS) examined were [oxy-Hb]_sup, [deoxy-Hb]_sup, total hemoglobin [total-Hb]_sup, Hb O₂ saturation (StO_2sup), and reduced scattering coefficient ( μs sup' ) in the supraclavicular region, as determined by NIR_TRS, and relative changes in corresponding parameters, as determined by NIR_CWS. The evidence comprises the relationships between the Ind_NIRS investigated and those determined by ¹⁸FDG-PET/CT; the correlation between the Ind_NIRS and cold-induced thermogenesis; the relationship of the Ind_NIRS to parameters measured by ¹⁸FDG-PET/CT, which responded to seasonal temperature fluctuations; the relationship of the Ind_NIRS and plasma lipid metabolites; the analogy of the Ind_NIRS to chronological and anthropometric data; and changes in the Ind_NIRS following thermogenic food supplementation. The [total-Hb]_sup and [oxy-Hb]_sup determined by NIR_TRS, but not parameters determined by NIR_CWS, exhibited significant correlations with cold-induced thermogenesis parameters and plasma androgens in men in winter or analogies to ¹⁸FDG-PET. We conclude that NIR_TRS can provide useful information for assessing BAT-d in a simple, rapid, non-invasive way, although further validation study is still needed.

Effects of pharmacological lesion of the nucleus retroambiguus region on the pharyngeal phase of swallowing

Pharyngeal swallowing is controlled by synaptic interactions within a swallowing central pattern generator (sw-CPG) that is composed of a dorsal and a ventral swallowing group (VSG). Here, we used electrical stimulation (10 s) of the superior laryngeal nerve (SLN; 20 Hz; pulse width: 100 μs) to explore the role of the VSG in an arterially-perfused brainstem preparation of rats. To investigate the effects of pharmacological lesion (local microinjection of an GABA(A)-R agonist) of the nucleus retroambiguus (NRA), a designated component of the VSG, we recorded phrenic (PNA) and vagal nerve (VNA) activities. Control SLN stimulation with stepwise increasing stimulus intensities (from 20 μA to 160 μA) elicited robust suppression of PNA and evoked sequential swallowing activity in the VNA. Lesioning of the NRA had no effect on the pattern of pharyngeal swallowing, but significantly increased the sensory gating of SLN inputs. We conclude that the NRA is not part of the VSG, but appears to have important roles for the central gating of swallowing.

Applicability of Supraclavicular Oxygenated and Total Hemoglobin Evaluated by Near-Infrared Time-Resolved Spectroscopy as Indicators of Brown Adipose Tissue Density in Humans

Brown adipose tissue (BAT) may potentially be used in strategies for preventing lifestyle-related diseases. We examine evidence that near-infrared time-resolved spectroscopy (NIR_TRS) is capable of estimating human BAT density (BAT-d). The parameters examined in this study are total hemoglobin [total-Hb]_sup, oxygenated Hb [oxy-Hb]_sup, deoxygenated Hb [deoxy-Hb]_sup, Hb O₂ saturation (StO_2sup), and the reduced scattering coefficient in the supraclavicular region (μ_s’_sup), where BAT deposits can be located; corresponding parameters in the control deltoid region are obtained as controls. Among the NIR_TRS parameters, [total-Hb]_sup and [oxy-Hb]_sup show region-specific increases in winter, compared to summer. Further, [total-Hb]_sup and [oxy-Hb]_sup are correlated with cold-induced thermogenesis in the supraclavicular region. We conclude that NIR_TRS-determined [total-Hb]_sup and [oxy-Hb]_sup are useful parameters for evaluating BAT-d in a simple, rapid, non-invasive manner.

Differential isoform expression of SERCA and myosin heavy chain in hypopharyngeal muscles

Composition of slow, fast and hybrid fibres of pharyngeal muscles, associated with pharyngeal movements and regulation, has been rarely studied. The present study aimed to identify expression of sarcoplasmic reticulum Ca2⁺ ATPase (SERCA) and myosin heavy chain (MHC) and hybrid isoforms in different pharyngeal muscles of young and aged rats as well as humans. Isoform expression profiles of SERCA, MHC and hybrid isoforms among six components of pharyngeal muscle were immunohistochemically evaluated in rat and human. The result showed that pharyngeal muscles predominantly expressed fast fibres (SERCA1 and MHCII), whereas expression of slow fibres (SERCA2 and MHCI) was low, but different depending on muscle components. Inner layer of pharyngeal muscles expressed more SERCA2 and hybrid fibres than the outer layer. Pharyngeal muscles in aged rats showed increased hybrid fibers and SERCA2. Human thyropharyngeus also showed a higher portion of fast fibres compared to cricopharyngeus. Thus, in contrast to abundance of fast fibres, slow and hybrid fibres are differentially expressed depending on muscle components and layers as well as aging. These results lead to further understanding of coordinated regulation for speech and swallowing. The unique data presented in this study on SERCA isoform expressions in both rats and human suggest an ability to handle calcium changes according functional demands.

Brown adipose tissue density measured by near-infrared time-resolved spectroscopy in Japanese, across a wide age range

F18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) along with computed tomography (CT) is a standard method for assessing brown adipose tissue (BAT) activity. We tested the usefulness of near-infrared time-resolved spectroscopy (NIRTRS) as a simple and noninvasive method for evaluating BAT density (BAT-d) by examining the effects of some factors known to influence BAT activity. The total hemoglobin concentration as a parameter of BAT-d was evaluated using NIRTRS in the supraclavicular region in 413 Japanese individuals. The associations were analyzed between BAT-d and sex, age, the percentages of body fat (%BF), visceral fat (VF), and the seasonal ambient temperature (AmT) fluctuations. Age was associated with decreased BAT-d (P  <  0.05). There was no sex difference in the BAT-d, except for those in their twenties. Multivariate analyses revealed that %BF and VF were correlated with BAT-d, and the lower AmT (around 4°C or 5°C) for 4 and 6 weeks prior to the measurement day was associated with an increase in the BAT-d. Our NIRTRS results were analogous to those reported with FDG18-PET  /  CT, indicating the usefulness of NIRTRS. BAT-d might increase during the 4 and 6 weeks after the AmT decreases to lower than 4°C or 5°C.

A non-linear organic reaction of malonate derivative as a base amplifier to generate imidazoles without producing gas

A novel base amplifier that is decomposed autocatalytically to generate imidazoles without producing gas has been designed.

Strategy for localized stenosis caused by Kawasaki disease: midterm results of percutaneous transluminal coronary balloon angioplasty in two infants

We report the midterm results of percutaneous transluminal coronary balloon angioplasty (PCBA) for localized stenosis (LS) caused by Kawasaki disease (KD). Two 2-year-olds, a girl and a boy, underwent PCBA for severe LS of the left anterior descending artery caused by KD. After 4 years, there was no ischemia and no significant restenosis in the target vessels. PCBA provided a good result for early appearing LS caused by KD in two small infants. The 5-years-old boy was the youngest patient to undergo percutaneous transluminal coronary rotablator. Although the postprocedure result was very effective, 1 year later asymptomatic occlusion occurred.

Biosystematic studies on the family Tofieldiaceae I. Phylogeny and circumscription of the family inferred from DNA sequences of matK and rbcL

In order to specify phylogenetic positions of the genera of Tofieldiaceae (Tofieldia, Triantha, Pleea, Harperocallis, Isidrogalvia), and to suggest reasonable circumscription of the family and genera of Tofieldiaceae, we determined DNA sequences of matK and rbcL for each genus of the family, and analyzed them phylogenetically with the 45 families and 113 genera of the monocots other than Tofieldiaceae, whose matK and rbcL sequences have already been reported. We found that Tofieldia, Triantha, Pleea, and Harperocallis form the same clade, which receives 100% bootstrap support. This clade can be regarded as corresponding to Tofieldiaceae, and is embedded in the clade of Alismatales (98%). On the other hand, Isidrogalvia is not included in this Tofieldiaceae clade, and positioned as sister to Narthecium (100%), embedded in the clade of Nartheciaceae (Dioscoreales) (100%). In the Tofieldiaceae, Pleea first diverges from the remaining three genera (100%), and then, Harperocallis diverges from the Tofieldia- Triantha complex (100%). In the Tofieldia- Triantha complex, five Tofieldia species form the same clade (100%), and two Triantha species form another clade (100%). Thus, Isidrogalvia should be transferred from Tofieldiaceae to Nartheciaceae. As Isidrogalvia, as well as the Nartheciaceae, have the carpels that are fully connate into a single style, Isidrogalvia fits the Nartheciaceae well with respect to carpel connation. After this transfer, the Tofieldiaceae correspond mainly to plants with almost free carpels and three styles. Pleea is better treated as an independent genus than included in Tofieldia. Triantha can be treated either as an independent genus or as congeneric with Tofieldia.

Acute occlusion of a simple aortic coarctation presenting as abdominal angina

A 9-year-old boy whose past history was remarkable for a heart murmur was diagnosed with abdominal angina due to acute occlusion of a simple coarctation of the aorta. Using a single cross-clamp, we accomplished an end-to-end anastomosis after resection of the coarctation. Paradoxical hypertension and abdominal angina were treated successfully with a continuous intravenous infusion of lipo-PGE-1 and nicardipine. Three years after his operation, the patient's blood pressure was normal, with no stenosis at the site of the anastmosis.

Antithrombin Modulates the Leukocyte???Endothelial Cell Interaction in the Staphylococcal Enterotoxin B-Challenged Mouse

BACKGROUND

The beneficial effects of antithrombin on endotoxemia are well known. The purpose of this study was to examine the effects of antithrombin in a supertoxin-induced sepsis.

METHODS

Mice were injected with staphylococcal enterotoxin B simultaneously with antithrombin. At 1 hour after injection, the mesenteric microcirculation was observed under intravital microscopy. In addition, humoral mediators were measured at the same time.

RESULTS

The number of rolling leukocytes on the endothelium was significantly reduced in the treated mice (p < 0.01). The decrease of white blood cell and platelet counts was significantly inhibited in the treated animals (p < 0.01 for both). A comparison of the intercellular adhesion molecule-1 (p < 0.05), soluble tumor necrosis factor-alpha receptor (p < 0.05), and interleukin-6 (p < 0.01) levels showed less increase in the treated mice.

CONCLUSION

Antithrombin showed a protective effects on the microcirculation of staphylococcal enterotoxin B-challenged mice by attenuating leukocyte-endothelial cell interaction. Suppression of adhesive molecule expression and cytokine production appears to play roles in this effect.

[Congenital tracheal stenosis due to complete cartilage rings with right pulmonary agenesis]

A 2-month-old male infant with severe dyspnea was diagnosed as having right pulmonary agenesis at birth and was admitted to our hospital after tracheal intubation with an endotracheal tube of 3 mm in diameter. However, the trachea was too stenotic to place the tube in the proper position. Chest X-ray on admission showed pneumonia of the left lung. Preoperative chest computed tomography (CT) scan and bronchoscopy showed that from the level of 12 mm beneath the coricoid cartilage, the trachea tapered and continuing to the tracheal carina and that the smallest tracheal level was located 18 mm distal from the coricoid cartilage, the area of which was 4 mm2. His respiratory condition rapidly deteriorated in spite of intravenous administration of antibiotics and mechanical ventilation. Percutaneous cardiopulmonary support (PCPS) was used to maintain his pulmonary function, and pericardial tracheoplasty was performed. Chest X-ray immediately after the operation did not show left lung reexpansion due to severe pulmonary edema. High-dose steroid pulse therapy was performed, but it was not effective. He died from acute respiratory failure due to infantile respiratory distress syndrome (IRDS) on postoperative day 3. The outcome in this case shows that it is very risky to repair tracheal stenosis in a patient with pneumonia using PCPS.

Jarcho-levin syndrome associated with a complex congenital heart anomaly

Jarcho-Levin syndrome is characterized by "crab-like" rib cage deformity and multiple vertebral anomalies that cause respiratory failure. Reports of complex congenital heart defects with this syndrome are rare. We describe a female infant with this syndrome and a complex congenital heart defect and review the literature. Congenital heart defects are occasionally complicated by Jarcho-Levin syndrome. Heart defects involving heterotaxic morphology should be included as one of the important clinical features of this syndrome.

Helical computer assisted tomography in pulmonary hypertension complicating left-to-right shunts--correlation with pulmonary hemodynamics

The present study analyzed the helical computer-assisted tomography (CAT) findings in 30 patients with pulmonary hypertension (PH) associated with left-to-right shunts; specifically, ventricular septal defect, 23; atrioventricular septal defect, 6; patent ductus arteriosus, 1. Eight patients had 21 trisomy. Age ranged from 1 to 18 (mean, 4.1) months, and body weight ranged from 2.6 to 10.7 (mean, 4.9) kg. In all patients, the chest CAT revealed patchy areas of high and low attenuation (mosaic pattern) and regional atelectasis in the lung fields. The volume of low attenuated lesions and of atelectasis, and the total lung volume were derived from integration of areas measured on the CAT image. The ratios of low attenuated lesion/total lung volume (Lo), volume of atelectasis/ total lung volume (Ate) and low attenuated lesion and volume of atelectasis/total lung volume (Lo&Ate) were compared with hemodynamic parameters measured at cardiac catheterization. The pulmonary to systemic resistance ratio correlated with Lo (r=0.61, p<0.01) and Lo&Ate (r=0.69, p<0.01), whereas the pulmonary vascular resistance correlated with Ate (r=0.53, p<0.01). Lo, Ate and Lo&Ate in the chest CAT are reliable parameters that can be used to estimate pulmonary vascular resistance in patients with PH associated with left-to-right shunts.

The C-terminal domain of thrombospondin-1 induces vascular smooth muscle cell chemotaxis

OBJECTIVE

Thrombospondin-1 (TSP-1), an acute-phase reactant implicated in vascular disease, is a 420-kd multifunctional glycoprotein chemotactic for vascular smooth muscle cells (VSMCs). TSP-1 has six domains of repeating homologous amino acid sequences: N-terminal, procollagen homology, type 1 repeat, type 2 repeat, type 3 repeat/RGD (T3), and C-terminal (COOH). The purpose of this experiment was to determine which domains of TSP-1 induce VSMC chemotaxis.

METHODS

A modified Boyden Chamber chemotaxis assay was used to assess VSMC migration. Serum-free medium, TSP-1, or each of the fusion proteins (10 and 20 microg/mL) synthesized for the different domains were placed in the bottom wells. Quiescent bovine aortic VSMCs (50,000) were placed in the top wells. After 4 hours at 37 degrees C, migrated VSMCs were recorded as cells per five fields (400x) and analyzed with the paired t test. To verify the fusion protein data, we performed chemotaxis assays with antibodies to each of the domains (25 microg/mL) combined with TSP-1 (20 microg/mL) in the bottom wells and VSMCs in the top wells.

RESULTS

The COOH domain significantly stimulated VSMC chemotaxis (P = <.001). To a lesser extent, the N-terminal and T3 domains also induced chemotaxis (P <.05). However, only the anti-COOH antibody (C6.7) and the anti-integrin-associated protein portion of COOH antibody (D4.6) significantly inhibited TSP-1-induced VSMC chemotaxis (by 85% and 92%, respectively).

CONCLUSIONS

These results implicate the COOH domain as the portion of the TSP-1 molecule primarily responsible for VSMC chemotaxis. This experiment suggests that future strategies in the prevention of VSMC migration, an initial step in the development of vascular lesions, may involve selective inhibition of the COOH domain of TSP-1.

A simple objective parameter for perfusion study of renal transplant

We proposed a simple parameter, the kidney-to-aorta ratio (KAR), for evaluation of renal transplant perfusion. KAR was calculated from the peak counts of the kidney and the aorta. The calculated values were compared with the visual interpretation of the radionuclide first-pass flow study, percent renal uptake (%RU), and tubular extraction rate (TER) by Bubeck's one point sampling method in 37 studies. KAR correlated well with the visual interpretation of the flow study and the other quantitative parameters. Representative cases, which showed the usefulness of KAR for the objective assessment of the perfusion status of renal transplants, were presented. In conclusion, KAR is a simple and practically useful parameter for objective evaluation and follow-up of renal transplant perfusion.

Inhibition of phosphatidylinositol 3-kinase and protein kinase C attenuates extracellular matrix protein-induced vascular smooth muscle cell chemotaxis

PURPOSE

Intimal hyperplasia (IH), a significant cause of vascular reconstructive failure, is characterized by abnormal vascular smooth muscle cell (VSMC) migration, proliferation, and extracellular matrix (ECM) deposition. The ECM proteins, thrombospondin-1 (TSP-1), fibronectin (Fn), and vitronectin (Vn) can induce VSMC migration; however, the cellular signaling pathways involved are not identical for each ECM protein. Phosphatidylinositol 3-kinase (PI3K) and protein kinase C (PKC) are two enzymes that have been associated with VSMC migration. We sought to elucidate the roles of these enzymes in TSP-1-, Fn-, and Vn-stimulated VSMC migration.

METHODS

Chemotaxis assays were performed by using a modified Boyden Chamber. TSP-1, Fn, or Vn (20 microg/mL) or serum-free media (SFM) was placed in the bottom wells of the chamber. Quiescent bovine aortic VSMC were preincubated with LY 294002 (100 micromol/L), a PI3K inhibitor, bisindolylmaleimide I (GF 109203X, 1 micromol/L), a PKC inhibitor, or in SFM alone for 30 minutes. VSMCs (50,000 cells per well) were then placed in the top wells of the chamber, and the assay was conducted for 4 hours at 37 degrees C. Results were recorded as the number of cells migrated per five fields (400x) and analyzed by means of the paired t test, with P value less than.05 considered to be significant (n = 3).

RESULTS

The VSMC migration was significantly increased by TSP-1, Fn, and Vn. LY 294002 inhibited TSP-1-, Fn-, and Vn-stimulated VSMC migration (85% to 89%, P <.05). GF 109203X inhibited only TSP-1-stimulated migration (65%, P <.05).

CONCLUSION

These results suggest that TSP-1-, Fn-, and Vn-stimulated migration is at least partially dependent on PI3K. However, only TSP-1 stimulated migration is at least partially dependent on PKC.

Endothelialization of the coils used to occlude a persistent ductus arteriosus: an angiographic study

To assess the endothelialization of the coils used to close a persistent ductus arteriosus (PDA), the present study comprised a review of the follow-up aortograms and pulmonary angiograms in 25 patients who underwent coil occlusion. The minimal diameter and the length of the PDA were measured prior to the procedure, and the shortest distance between the aortic end of the deployed coil and the aortic end of the PDA was measured after coil deployment. Evidence of endothelial coverage of the coil was sought on follow-up angiograms performed 6-24 (15+/-5) months later and the factors that determined the thickness of the endothelial coverage on the aortic end were investigated. Separation of the coil and the contrast column were detected at the aortic end in all cases and at the pulmonary end in 18 of 25 cases. The thickness of the separation ranged from 0.4 to 1.3 (0.7+/-0.2) mm at the aortic end and 0.3 to 0.8 (0.6+/-0.2) mm at the pulmonary end. The length of the ductus and of the ampulla had a significant positive correlation with the thickness of the aortic end separation. Apparent endothelial coverage of the coil was completed by 6 months after coil occlusion. Infective endocarditis or thromboembolism is an unlikely complication once endothelium covers the implanted coil.

[Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to renal transplantation]

Measurement of 99mTc-MAG3 plasma clearance (CLmag) based on one-compartment model (MPC method) was applied to renal transplantation and evaluated for the factors which might affect the calculated results, especially concerning renal depth. Correlation coefficient of CLmag between MPC method using real renal depth and Russell or Bubeck single sampling method was good (r = 0.852 or 0.876, respectively). Regression equation between MPC method and Russell method was y = 1.044x - 3.0 and was more closer to y = x than that between MPC method and Bubeck method. CLmag of MPC method calculated by estimated renal depth from the abdominal thickness was also similar to that by real renal depth. Even if the fixed renal depth, 4 cm, was applied, the coefficient and regression equation between MPC method and Russell method were r = 0.884 and y = 1.004x - 10.2. In conclusion, MPC method is applicable to the evaluation of renal transplants. Though measuring renal depth is best, calculation with fixed renal depth of 4 cm might be practically acceptable.

Stretching of the ductus: an important factor in determining the outcome of coil occlusion

The present study measured the minimal diameter of the ductus (minimal D), the stretched minimal diameter (stretched D), and the stretch index (SI) before coil occlusion in 25 patients with a patent arterial duct. The following factors were compared in the success group (22 cases, coil successfully placed after initial deployment) versus the failure group (3 cases): minimal D, stretched D, SI, the sum of the loop diameter of coils (the loop diameter), the sum of the product of the loop diameter and the number of loops (the loop diameter and number), the loop diameter/minimal D, the loop diameter/stretched D, the loop diameter and number/minimal D, and the loop diameter and number/stretched D. In the failure group, minimal D, stretched D, SI, the loop diameter, and the loop diameter and number were larger than in the success group. The loop diameter/stretched D, and the loop diameter and number/stretched D were smaller in the failure group. Although the loop diameter and number/minimal D was slightly smaller in the failure group, the loop diameter/minimal D was comparable. It is concluded that the stretched D is more reliable than minimal D to determine the appropriate size of coil for successful initial deployment.

[Comparison between continuous intravenous and oral administration of 5-FU with LV]

In case of 5-fluorouracil (5-FU)/leucovorin (LV) treatment, which is one of the most effective forms of chemotherapy for colorectal carcinoma, 5-FU is usually continuously infused from the venous route. However, since this continuous infusion limits the patients' active daily life, oral administration is preferable. In the present study, we evaluated the efficacy and side effects of orally administered 5-FU/LV.

MATERIAL AND METHODS

In the continuous intravenous infusion group (civ group), colon 26 bearing mice were cannulated into central vein from external jugular vein. From this route, either 5, 10, or 20 mg/kg of 5-FU was continuously infused for 7 days (n = 6). In another group, either 10, 20, 40 mg/kg of 5-FU was infused orally (po group, n = 6). The other 6 animals were used for the non-treatment group. In the next series, 100 mg/kg of LV was added for each group above. Tumor volume, thymidylate synthase inhibition rate (TSIR) and body weight were measured at the end of infusion. During the experimental period, mice had free access to chow and water.

RESULTS

The tumor/control (T/C) volumes ratio showed that approximately twice the orally administered 5-FU dose had an anti-tumor effect equal to that of 5-FU administered intravenously. Synergic antitumor effects by LV were only revealed in the civ group. Significant body weight loss was recognized only in the po group at a 5-FU dose of more than 20 mg/kg. In summary, since the modulation effect of LV was recognized only with continuously intravenous infusion of 5-FU, further improvement of oral administration is required in the LV/5-FU combination therapy.

Disopyramide improves hypoxia in patients with tetralogy of Fallot through a negative inotropic action

The hemodynamic and right ventricular volumetric effects of disopyramide were investigated in patients with tetralogy of Fallot (TF). Intracardiac pressure and oxygen saturation were measured, before and after intravenous administration of disopyramide (2 mg/kg) in 7 patients who had not had previous surgery. Right ventricular volume and the diameter of its outflow tract were analyzed in these 7 and in a further 4 patients with a previous shunt. Aortic oxygen saturation increased from 90.4+/-7.5 (mean+/-SD) to 94.1+/-5.5% (p<0.05) with an increase in pulmonary blood flow and pressure. The systolic pressure gradient between the main pulmonary artery and the right ventricle decreased from 59+/-8 to 42+/-9 mmHg (p<0.01). Aortic pressure fell from 77+/-5 to 67+/-4 mmHg (p<0.05). Systemic vascular resistance increased from 15.3+/-2.2 to 19.4+/-3.3 u x m2 (p<0.05). Pulmonary vascular resistance remained unchanged. The diastolic and systolic diameter indices of the right ventricular outflow tract increased from 17.8+/-3.8 to 20.5+/-3.4 and from 6.5+/-3.0 to 10.4+/-2.2 mm/m2, respectively (p<0.01), whereas the right ventricular ejection fraction decreased. Disopyramide improves systemic oxygen saturation in patients with TF through its negative inotropic action on the right ventricle.

Successful stenting of congenital bronchial stenosis in infancy

Recently, stent implantation has become the treatment of choice for patients with tracheobronchial stenosis due to malignant tumours, tuberculosis and recurrent stenosis following lung transplant. However, reports on this procedure in infants with congenital bronchial stenosis are extremely rare. We report successful stent implantation in an infant with congenital left bronchial stenosis followed by rapid improvement in his respiratory condition.

CONCLUSION

The use of a stent in infants is still controversial because size mismatch will take place with growth. However, we believe that implantation of a metallic stent can be the preferred treatment of congenital bronchial stenosis even in small infants.

Epinephrine-induced constriction of the persistent ductus arteriosus and its relation to distensibility

The aim of this study was to investigate whether distensibility of the persistent ductus arteriosus (PDA) might predict its potential for vasoconstriction. Epinephrine-induced constriction and stretching were investigated in 10 patients with PDA. Age, sex, ductus type, its minimal diameter, its stretched minimal diameter, and its stretch index were compared between epinephrine responders and non-responders. Age, sex, weight or the configuration or size of the PDA did not predict stretchability. The stretch index was significantly greater in responders (1.7-2.0, 1.8+/-0.1) than in non-responders (1.3-1.7, 1.4+/-0.2, p<0.01). Stretching of the PDA may depend on the elasticity of the vascular wall, which in turn is determined by preservation of vascular smooth muscle.

An infant with Costello syndrome complicated with fatal hypertrophic obstructive cardiomyopathy

We report a 3-month-old girl with Costello syndrome complicating fatal hypertrophic obstructive cardiomyopathy. She had typical findings of this syndrome, slight dyspnea and persistent wheezing. Doppler echocardiography revealed asymmetric septal hypertrophy and systolic anterior movement of the anterior mitral leaflet. There was grade 1 mitral regurgitation. Although once her heart failure had been controlled medically, she died suddenly following deterioration of her heart condition. Costello syndrome can complicate fatal hypertrophic obstructive cardiomyopathy.

Disopyramide: a promising new approach to the medical treatment of the hypercyanotic spell complicating tetralogy of Fallot

Under continuous ECG and oxygen saturation (SpO2) monitoring, the following measurements were taken by Doppler echocardiography in 6 consecutive patients with tetralogy of Fallot (TF) before and after intravenous administration of disopyramide (2mg/kg): left ventricular shortening fraction (LVSF); peak velocities in the right ventricular outflow tract (RVOT); diastolic and systolic internal diameters of the right ventricular outflow tract (dRVOT, sRVOT); and systolic blood pressure. SpO2 increased (p<0.01) from 78 to 98 (89 +/- 7, mean +/- standard deviation)% to 86-99 (94 +/- 5)%. LVSF decreased (p<0.05) from 0.34-0.56 (0.42 +/- 0.08) to 0.22-0.54 (0.33 +/- 0.13). The systolic blood pressure fell slightly (p<0.05) from 68-92 (79 +/- 8) to 64-92 (71 +/- 11)mmHg. The sRVOT increased (p<0.05) from 2.1-4.8 (2.7 +/- 1.5)mm to 3.0-8.1 (4.9 +/- 2.4)mm, while RVOT peak velocity decreased (p<0.05) from 2.20-4.88 (3.70 +/- 0.97)m/sec to 2.05-4.07 (2.92 +/- 0.72)m/sec. Disopyramide alleviates hypoxia in patients of TF through its negative inotropic action on right ventricular outflow obstruction.

Coarctation of persistent right fifth aortic arch and pulmonary sequestration

A 41-day-old boy was transferred to our department with severe congestive heart failure. Digital subtraction counter current aortography, and antegrade aortography, revealed coarctation of a persistent right fifth aortic arch, stenosis of the origin of an aberrant left subclavian artery, and sequestration of the lower lobe of the right lung. As his heart failure seemed to be caused not only by pressure overload to the left ventricle following coarctation, but also by the volume load associated with the shunting effect of the pulmonary sequestration, we performed transcatheter balloon dilation of the coarctation and the origin of the aberrant subclavian artery, together with embolization of the aberrant pulmonary artery. His heart failure responded dramatically to these procedures.

Stretched minimal diameter of the ductus and coil occlusion

BACKGROUND

Stretching of the ductus was supposed to determine the size mismatch of the coil with the ductus in coil occlusion that results in residual leak or migration.

METHODS

We measured the minimal diameter (D) and the stretched minimal diameter (S) of the ductus in 12 patients with patent ductus arteriosus (PDA). The stretch index (SI) was calculated as S divided by D. We calculated ratios of the loop diameter of the first implanted coil to D (C1/D) and S (C1/S) and those of the sum of all the loop diameters of all implanted coils for complete closure to D (total C/D) and to S (total C/S).

RESULTS

Stretched minimal diameter divided by D was 1.8 +/- 0.3. Ratios of the loop diameter of the first implanted coil to D (C1/D), and S (C1/S) were 3.7 +/- 1.8 and 2.1 +/- 0.9, respectively. Ratios of the sum of all the loop diameters of all coils to D (total C/D) and S (total C/S) were 5.2 +/- 1.6 and 2.9 +/- 0.9, respectively. Standard deviations of C1/S and total C/S are significantly smaller than those of C1/D and total C/D, respectively.

CONCLUSIONS

The narrowest segment of the ductus could be stretched to twice the size of the minimal diameter. The stretched minimal diameter may be a more reliable parameter to select the loop diameter of coils than the angiographic minimal diameter.

[Somatic mosaicism of p(CTG)n expansion in a case of myotonic dystrophy with parotid tumor]

Myotonic dystrophy (MD) is an autosomal dominant systemic disorder with an unstable expansion of the CTG triplet repeat in the 3'-untranslated region of the gene encoding myotonine protein kinase (DMPK) which maps to chromosome 19q13.3. Somatic mosaicism of CTG repeats in MD has been reported; and it has been observed that CTG repeats in tumor tissues associated with MD are more expanded than the other tissues. It is not rare that parotid tumors are found in patients with MD. We performed Southern blot analysis for tissues from the parotid tumor, the normal parotid gland, the skeletal muscles, and the leukocyte from a 60-year-old patient with MD. CTG repeat was most expanded in the parotid tumor, and the normal parotid gland had longer expansion of CTG repeat than the skeletal muscles. The leukocyte had the shortest expansion of CTG repeat. The expansion of CTG repeat in the parotid tumor may be related to active cell division and may underlie the occurrence of tumors in MD.

Is early surgery always necessary in patients with aortic valve prolapse complicating an Eisenmenger-type ventricular septal defect?

BACKGROUND

The report presents three patients who showed a typically prolapsed aortic cusp with or without aortic regurgitation associated with a malalignment-type perimembranous defect, the so called Eisenmenger-type ventricular septal defect.

RESULTS

Each patient developed spontaneous complete or near closure of the ventricular septal defect without worsening of the aortic regurgitation.

CONCLUSIONS

These cases suggest that prolapsed aortic cusp complicating a malalignment perimembranous ventricular septal defect is not always an absolute indication for early surgery to prevent progressive aortic regurgitation.

Plasma thromboxane B2 concentration in patients with ventricular septal defect and pulmonary hypertension

Plasma thromboxane B2 (TXB2)-a stable metabolite of thromboxane A2 (TXA2)-conventional hemodynamic parameters, mean pulmonary input energy (input energy), and mean pulmonary output energy (output energy) were measured to assess platelet activation in 21 patients with pulmonary hypertension and a ventricular septal defect (VSD). The patients were divided into 2 groups: group A (normal range) and group B (high level). TXB2 levels were measured by radioimmunoassay. There was no relationship between plasma TXB2 concentrations and conventional hemodynamic parameters except the pulmonary-to-systemic pressure ratio. Output-to-input energy ratio was correlated logarithmically with the plasma TXB2 concentration. We concluded that patients with output/input energy ratio >0.15 had a high TXB2 concentration and activated platelets in pulmonary capillaries.

Hemolysis complicating coil occlusion of patent ductus arteriosus

We report on 5 patients who developed hemolysis (the Hemolysis group) following coil occlusion for PDA, and compare their data to 66 cases which were not complicated by hemolysis despite residual leak (the No Hemolysis group). A significant leak with a heart murmur was more frequent in the Hemolysis group than in the No Hemolysis group. The ratio of the sum of the loop diameter of coils to the minimal diameter of the ductus (C/D) in those who developed persistent hemolysis that needed a second intervention (2.2+/-0.4) was significantly smaller than in the No Hemolysis group (3.1+/-1.1). Persistent hemolysis can occur if a significant residual shunt remains after implantation of coils with small C/D. As this complication may be avoided by complete closure or, if not complete, a minimal leak, we should be careful to make residual leaks as small as possible by the use of multiple coils.

Coil occlusion for patent ductus arteriosus in Japan

We surveyed Japanese experience of coil occlusion of patent ductus arteriosus up to 30 September 1996 by sending questionnaires to 175 hospitals. Thirty-four hospitals reported outcome data for 231 procedures in 218 patients. Successful implantation was achieved in 94% and acute complete closure of the ductus occurred in 71% of those in whom implantation of the coil was successful. Of the latter, 83% reported late complete closure. When those patients who underwent reocclusion for residual shunt are included, 89% attained complete closure. No life-threatening complications have occurred so far. Late reopening was reported in 3 cases. Although the angiographic type of ductus was significantly related to successful implantation (p < 0.01), there was no significant correlation with complete occlusion. Ductuses with a minimum diameter greater than 3 mm had a decreased chance of successful implantation, whereas those less than 2 mm had a greater incidence of complete closure.

Antegrade or retrograde catheterization across a ventricular septal defect

The success rate and the most suitable catheter tip for crossing over various types of ventricular septal defects (VSDs) were examined as a preliminary study for transcatheter closure of VSD. The 18 consecutive patients with various types of VSD were aged from 1 to 95 (mean [+/- SD] 13 +/- 22) months. Body weight was 3.7 to 25.0 (8.0 +/- 5.1) kg. Two-dimensional echocardiography showed that the maximal diameter of the defects ranged from 1.0 to 12.0 (7.5 +/- 3.1) mm. There were 10 patients with perimembranous defects, 4 with outlet defects, 2 with muscular defects, and 2 with tetralogy of Fallot with perimembranous defects. An angiographic balloon catheter, or an original or modified Judkins right coronary catheter could be passed through the VSD antegradely or retrogradely in 16 of 18 patients. In only two patients, with a small VSD of 2.0 and 1.0 mm, the catheter could not cross over the defect. The catheter entered the ascending aorta antegradely in 12 cases. The Judkins right coronary catheter is most suitable for crossing a VSD either antegradely or retrogradely.

Combined use of detachable coil against persistent mechanical hemolysis after transcatheter occlusion using Rashkind umbrella device in adult patient with patent ductus arteriosus

Mechanical hemolysis after transcatheter occlusion of the patent ductus arteriosus using the Rashkind umbrella device has been postulated as a rare, but serious complication, even necessitating surgical repair. A rare, case of an adult patient with massive hemolytic anemia, successfully controlled by the combined use of several detachable coil devices is reported. The use of coil devices might be considered as a therapeutic option in such cases.

Plasma concentration and acute clinical effects of docarpamine, orally active dopamine prodrug, in infants

Currently, there are no data available on the optimal doses and efficacy of docarpamine in infants. In the present study, three doses of docarpamine, 15.0-20.4 (19.0 +/- 1.9; mean +/- SD) mg/kg per dose every 8 h to 10 infants suffering heart failure. Age and bodyweight were from 1 to 4 (1.4 +/- 1) months and 2960-5160 (3350 +/- 872) g, respectively. In all infants, plasma concentrations of free dopamine were measured 1, 2 and 3 h after the first administration. Heart rate and systolic blood pressure were examined before and at the same time as the first administration. In seven infants, the 24 h urinary output and urinary excretion of electrolytes and creatinine before and during docarpamine were measured. Peak plasma concentration of free dopamine (ng/mL) was achieved after 1 or 2 h of administration, 0-163.1 (37.9 +/- 47.2) and 0-105.0 (37.8 +/- 39.3), respectively. The concentration had decreased rapidly by 3 h to 0-34.2 (12.4 +/- 11.0). Both heart rate (b.p.m.) and blood pressure (mmHg) tended to increase from 120-154 (140 +/- 15) and 56-90 (76 +/- 11) to a peak of 124-162 (148 +/- 14) and 70-92 (79 +/- 8), respectively (P = 0.197, P = 0.289). There were no significant changes in urinary output or excreta. Oral docarpamine of 15-20 mg/kg per dose can achieve plasma free concentrations of dopamine that increase heart rate and systolic blood pressure.

High dose of intravenous antithrombin III without heparin in the treatment of disseminated intravascular coagulation and organ failure in four children

In several animal experiments, high doses of antithrombin III concentrates have shown beneficial effects on mortality and reversal of coagulation abnormalities which had resulted from disseminated intravascular coagulation. Other experiments have suggested that antithrombin III infusion without heparin is effective in the treatment of organ failure. We clinically treated children suffering disseminated intravascular coagulation only with antithrombin concentrate. Four patients suffering disseminated intravascular coagulation with organ failure were selected. We started antithrombin III concentrate infusion as soon as the diagnosis was established. The dosage of antithrombin III was 120-250 units/kg/day for 2 or 3 days. Heparin was not used. All 4 patients recovered completely and quickly without any complications within 14 days. We suggest that the high-dose antithrombin III infusion without heparin is an effective and safe therapy for disseminated intravascular coagulation with organ failure.

Diagnosis of renovascular hypertension by echo-Doppler velocimetry

A 13 year old boy suffering hypertension was examined for peripheral plasma renin, angiotensin-I, angiotensin-II and aldosterone. All data were within the normal range. The Captopril test and renal scintigraphy (both with and without Captopril) also showed normal patterns. Echo-Doppler velocimetry of the renal artery revealed that left renal arterial peak flow velocity was fast (3.4 m/s). The patient was therefore diagnosed with left renal arterial stenosis. Angiography demonstrated the duplex of the left renal artery and stenosis of the left lower renal artery. Percutaneous transluminal angioplasty was successfully performed.

Catecholamine-induced ductus arteriosus constriction in children

Our data suggest that the vascular smooth muscle of the PDA remains capable of constriction beyond a patient's infancy, at least at the pulmonary end. In some cases of PDA, catecholamines may induce late closure.

[Pure word deafness after cerebral hemorrhage in the left temporal lobe: a case report]

We report a patient with pure word deafness after subcortical hemorrhage in the left temporal lobe. Repetition and auditory comprehension were severely impaired, while reading and visual comprehension of the same material were almost normal. He did not show hearing loss, but speech discrimination and melody recognition was poor. On the speech discrimination test, his score was low especially in the right ear. The threshold on the directional hearing test was mildly elevated. There was no temporal summation by click sounds. CT and MRI disclosed a subcortical hematoma in the left superior temporal gyrus. PET demonstrated hypoperfusion in the surrounding area, which was not activated by hearing a story. It was considered that pure word deafness in this case was due to the interruption of auditory inputs to Wernicke's area from both hemisphere by the hematoma. After 5 months, auditory comprehension recovered so that he did not have difficulty in conversation. Speech discrimination improved in both ears, probably due to the recovery of two auditory pathways; the ipsilateral pathway through the left auditory radiation and the contralateral pathway through the right auditory radiation and the corpus callosum. This case suggests that in pure word deafness due to a unilateral lesion, the improvement in speech discrimination during follow-up period may provide a clue as to the site of the responsible lesion and its recovery.