Challenges of pediatric pharmacotherapy: A narrative review of pharmacokinetics, pharmacodynamics, and pharmacogenetics

PURPOSE

Personalized pharmacotherapy, including for the pediatric population, provides optimal treatment and has emerged as a major trend owing to advanced drug therapeutics and diversified drug selection. However, it is essential to understand the growth and developmental characteristics of this population to provide appropriate drug therapy. In recent years, clinical pharmacogenetics has accumulated knowledge in pediatric pharmacotherapy, and guidelines from professional organizations, such as the Clinical Pharmacogenetics Implementation Consortium, can be consulted to determine the efficacy of specific drugs and the risk of adverse effects. However, the existence of a large knowledge gap hinders the use of these findings in clinical practice.

METHODS

We provide a narrative review of the knowledge gaps in pharmacokinetics (PK) and pharmacodynamics (PD) in the pediatric population, focusing on the differences from the perspective of growth and developmental characteristics. In addition, we explored PK/PD in relation to pediatric clinical pharmacogenetics.

RESULTS

The lack of direct and indirect biomarkers for more accurate assessment of the effects of drug administration limits the current knowledge of PD. In addition, incorporating pharmacogenetic insights as pivotal covariates is indispensable in this comprehensive synthesis for precision therapy; therefore, we have provided recommendations regarding the current status and challenges of personalized pediatric pharmacotherapy. The integration of clinical pharmacogenetics with the health care system and institution of educational programs for health care providers is necessary for its safe and effective implementation. A comprehensive understanding of the physiological and genetic complexities of the pediatric population will facilitate the development of effective and personalized pharmacotherapeutic strategies.

Recent updates on echocardiography and ultrasound for Kawasaki disease: beyond the coronary artery

Kawasaki disease (KD) is a systemic vasculitis with a predilection for damage to the coronary arteries. In the acute phase, clinical decision making for KD relies on the measurements of the coronary z-score obtained by 2-dimensional echocardiography (2DE). In the convalescent phase, KD patients with coronary artery abnormalities (CAAs) eventually show arteriosclerotic vascular remodeling characterized by marked intimal proliferation and neoangiogenesis after KD vasculitis, which often induces myocardial ischemia. To date, several well-established surrogate markers including dobutamine stress echocardiography (DSE), the carotid intima-media thickness (CIMT) and flow-mediated dilatation (FMD), have been made available for risk assessment and the prediction of cardiovascular disease (CVD) in KD patients. Additionally, the use of carotid contrast-enhanced ultrasonography (CEUS), has enabled the visualization and quantification of the adventitial vasa vasorum (VV) network, assessing active vascular remodeling at remote arterial sites in KD patients with CAAs. However, there was no evidence of major vascular structural changes in KD patients in whom CAAs had never been detected. Thus, assessment of multiple modalities using 2DE may provide direct information not only on the vascular health but also on the stratification of the risk of CVD in KD patients with CAAs.

Reassessment of carotid intima-media thickness by standard deviation score in children and adolescents after Kawasaki disease

Previous studies that used carotid ultrasound have been largely conflicting in regards to whether or not patients after Kawasaki disease (KD) have a greater carotid intima-media thickness (CIMT) than controls. To test the hypothesis that there are significant differences between the values of CIMT expressed as absolute values and standard deviation scores (SDS) in children and adolescents after KD and controls, we reviewed 12 published articles regarding CIMT on KD patients and controls. The mean ± SD of absolute CIMT (mm) in the KD patients and controls obtained from each article was transformed to SDS (CIMT-SDS) using age-specific reference values established by Jourdan et al. (J: n = 247) and our own data (N: n = 175), and the results among these 12 articles were compared between the two groups and the references for comparison of racial disparities. There were no significant differences in mean absolute CIMT and mean CIMT-SDS for J between KD patients and controls (0.46 ± 0.06 mm vs. 0.44 ± 0.04 mm, p = 0.133, and 1.80 ± 0.84 vs. 1.25 ± 0.12, p = 0.159, respectively). However, there were significant differences in mean CIMT-SDS for N between KD patients and controls (0.60 ± 0.71 vs. 0.01 ± 0.65, p = 0.042). When we assessed the nine articles on Asian subjects, the difference of CIMT-SDS between the two groups was invariably significant only for N (p = 0.015). Compared with the reference values, CIMT-SDS of controls was within the normal range at a rate of 41.6 % for J and 91.6 % for N. These results indicate that age- and race-specific reference values for CIMT are mandatory for performing accurate assessment of the vascular status in healthy children and adolescents, particularly in those after KD considered at increased long-term cardiovascular risk.

Characteristics of earlier atherosclerotic involvement in adolescent patients with Kawasaki disease and coronary artery lesions: significance of gray scale median on B-mode ultrasound

OBJECTIVE

To test the hypothesis that textural changes in the carotid intima-media complex (IMC) detected by B-mode ultrasound are associated with the difference of remodeling process in earlier atherosclerotic involvement in patients with Kawasaki disease (KD) and coronary artery lesions (CALs).

METHODS

Eighteen patients with KD and CALs (mean age 17.2 years), 17 patients with heterozygous familial hypercholesterolemia (FH) (mean age 16.9 years) and 15 age-matched healthy controls (Cont) were assessed and compared for carotid intima-media thickness (CIMT), elastic property (E(p)), and first- and second-order statistics.

RESULTS

KD showed significantly higher gray scale median (GSM) than FH and Cont. KD and FH showed significantly higher CIMT, entropy and lower angular second moment than Cont, but no significant difference was found between KD and FH.

CONCLUSION

Higher GSM in KD may indicate alteration of tissue components and heterogeneity of IMC, suggesting the development of arteriosclerotic vascular remodeling after vasculitis. This is distinct from that of atherosclerosis with lower GSM often observed in FH.

Growth of Gaas on Si Using Algap Intermediate Layer

We have studied heteroepitaxial growth of GaAs on Si using an AlxGa1−xP intermediate layer in an atmospheric-pressure metal organic chemical vapor deposition (NOCVD) reactor. The crystallinity of the GaAs layer depends on AlP composition(x) of the intermediate layer. The bett crystal quality of GaAs layer is obtained when the AlP composition(x) of the intermediate layer is close to 0.5. The X-ray FWHX of 180 arcs and the etch pit density (EPD) of 2.5 × 107cm−2 were obtained in this GaAs/AlGaP/Si structure.

Age-related acceleration of endothelial dysfunction and subclinical atherosclerosis in subjects with coronary artery lesions after Kawasaki disease

The objective of this study was to test the hypothesis that accelerated endothelial dysfunction and the development of premature atherosclerosis are associated with age in subjects with coronary artery lesions after Kawasaki disease (KD). A case-control study was performed at a university hospital that included 35 post-KD subjects across a wide age range (range, 8-42 years) without traditional cardiovascular risk factors and 35 age- and sex-matched healthy control subjects (Cont). Flow-mediated dilatation (FMD) of the brachial artery-induced by reactive hyperemia, intima media thickness (IMT), and elastic modulus (Ep) of the common carotid artery were compared between KD and Cont subjects assessed against age. KD subjects had slightly higher levels of body mass index, lipid profile, and HbA1c than Cont subjects, but the differences were not significant. The mean IMT (p < 0.001), age-adjusted percentage normal IMT (%N IMT; p < 0.0001), and Ep (p < 0.001) were significantly higher in KD than Cont subjects, and the peak FMD% (p < 0.01) was significantly lower in KD than Cont subjects. There were significant correlations between FMD% and age (r = -0.51 p < 0.0001), IMT and age (r = 0.68, p < 0.001), and Ep and age (r = 0.58, p < 0.01) in KD but not Cont subjects. When the difference in FMD% between KD and matched Cont subjects (DeltaFMD%) was plotted against age, no significant relationship was found, although significant correlations between DeltaIMT and age (r = 0.52, p < 0.01) as well as between DeltaEp and age (r = 0.46, p < 0.05) were observed. When we defined values that were +2.0 SD over the mean control values (i.e., %N IMT >or= 120% and/or Ep >or= 50 kPa) as markers of subclinical atherosclerosis, 15 subjects met the criteria. Subjects over the age of 22 years were more likely to have (OR = 16.54, p = 0.0001) subclinical atherosclerosis in this cohort. Our results suggest that endothelial dysfunction and the development of premature atherosclerosis were accelerated in adult post-KD compared to Cont subjects.

B-flow sonographic demonstration for assessing carotid atherosclerosis in young patients with heterozygous familial hypercholesterolemia

PURPOSE

To determine whether bloodstream swirls detected with B-mode flow (B-flow) sonography at the region of the carotid bifurcation can predict the early progression of atherosclerosis, we prospectively examined the relationships between the size of bloodstream swirls as identified with B-flow sonography, the local mechanical behavior of the common carotid artery (CCA), and some cardiovascular risk factors in young patients with heterozygous familial hypercholesterolemia (FH).

METHODS

Thirty-eight young patients (mean age 25.8 +/- 14.1 years) with FH were evaluated for the following parameters: age, sex, body mass index, degree of dyslipidemia, presence of a plaque, intima-media thickness (IMT), elastic modulus (Ep) and internal diameter of the CCA via duplex scan, wall shear stress, maximal diameter of the bloodstream swirl (Sm) at bifurcation, maximal diameter of the CCA (Cm) at the level of the swirl's center, and diameter ratio (Sm/Cm) via B-flow sonography.

RESULTS

Bloodstream swirls of varying size at the site of bifurcation were observed in all patients. Six (15.7%) out of 38 patients exhibited plaques at bifurcation. All plaques were located at the far wall and were in contact with the distal portion of the bloodstream swirl as observed with B-flow sonography. Univariate analysis revealed that Sm/Cm and Sm were positively correlated with age, presence of a plaque, IMT, and Ep and were negatively correlated with shear stress. Multivariate analysis revealed that Sm was significantly correlated with age (P < 0.01) and Ep (P < 0.05).

CONCLUSIONS

Our results suggest that a bloodstream swirl visualized at the carotid bifurcation with B-flow sonography may be an indicator of a local mechanism for the age-related progression of atherosclerosis in young patients with FH.

Adult Kawasaki disease unrelated to epstein-barr virus and group A Streptococcus

A 23-year-old Japanese woman with a fever and generalized skin eruptions was referred to our hospital in July 1999. At admission, her temperature was 38.9 degrees C, and she had fluctuating symptoms including erythema of the extremities, conjunctival hyperemia, strawberry tongue, and generalized skin eruptions, but lymphadenopathy was not verified. An initially elevated urine leukocyte count (more than 100 per high power field) later returned to normal range without antibiotic therapy. Adult Kawasaki disease was diagnosed on the basis of the above symptomology. Echocardiograph showed transient effusion in the pericardium. Using the Harada scoring system for treatment of Kawasaki disease, we gave the patient aspirin and did not administer intravenous immunoglobulin. The clinical course was uneventful, and on the day of discharge (day 22 after onset), the laboratory test results were nearly normal. Laboratory test results were negative for both Epstein-Barr virus and group A Streptococcus.

Familial combined hyperlipidemia (FCHL) in children: the significance of early development of hyperapoB lipoproteinemia, obesity and aging

It is not easy to make diagnose FCHL in children, since a clear expression of lipoprotein abnormality is unlikely and standard criteria have not yet been established. We investigated eight cases of childhood FCHL and their families with respect to familial history, anthropometric parameters and serum lipoprotein levels, to explore the characteristics of childhood FCHL. To diagnose childhood FCHL it is necessary to clarify both the family history and lipid profiles of the parents. In this study, two prominent features were suggested; that serum TG level is affected by both obesity and age, and also in particular, that a significantly elevated level of serum apoB is a predominant feature of FCHL in childhood. It was found that hyperapoB may be revealed antecedently without other lipid abnormalities at an early age. Regardless of other lipoprotein abnormality, it was suggested that hyperapoB might be added to the early diagnostic criteria for FCHL.

Detection of myocardial contractile reserve by low-dose dobutamine quantitative gated single-photon emission computed tomography in patients with Kawasaki disease and severe coronary artery lesions

We studied 24 patients with severe coronary artery lesions to assess myocardial perfusion and left ventricular contractile reserve simultaneously using low-dose dobutamine quantitative electrocardiographically gated single-photon emission computed tomography in patients with Kawasaki disease. Low-dose dobutamine infusion was started after an injection of technetium-99m tetrofosmin at rest. Myocardial contractile reserve was evaluated using the post-stress and low-dose dobutamine images, and myocardial perfusion was evaluated using the stress and rest images. Quantitative electrocardiographically gated single-photon emission computed tomography during low-dose dobutamine infusion is a useful and safe method for the combined evaluation of myocardial contractile reserve and myocardial perfusion.

Non-invasive measurement of coronary flow reserve in children with Kawasaki disease

OBJECTIVE

To investigate whether transthoracic Doppler echocardiography (TTE) can reliably measure the coronary flow reserve in the left anterior descending coronary artery in children with Kawasaki disease.

DESIGN

Coronary flow velocity in the distal left anterior descending coronary artery was measured by TTE and was compared with that obtained by intracoronary Doppler guide wire. The ratio of maximum hyperaemia (intravenous administration of adenosine triphosphate, 160 microg/kg/min) to baseline peak (mean) diastolic coronary flow velocity in the distal artery was used as an estimate of coronary flow reserve.

SETTING

University hospital.

PATIENTS

10 patients with significant left anterior descending coronary stenosis (> 70% diameter stenosis) (group A) in the proximal or middle portion of the artery and 14 patients (group B) without significant stenosis, all with Kawasaki disease documented by previous coronary angiography.

RESULTS

The reduced hyperaemic coronary flow velocity in group A compared with group B resulted in a markedly lower coronary flow reserve, derived from both peak diastolic velocity and mean diastolic velocity by either technique of investigation. Multivariate analysis identified the best predictor of left anterior descending coronary artery stenosis to be a coronary flow reserve of < or = 2.2, derived from mean diastolic flow velocity measured using TTE (sensitivity 90%, specificity 100%, accuracy 96%). A good correlation was found between diastolic velocity derived values for coronary flow reserve measured using both TTE and Doppler guide wire (r = 0.92, p = 0.0001).

CONCLUSIONS

Coronary flow reserve in the distal left anterior descending coronary artery can be accurately measured using TTE without any intravascular instrumentation in children with Kawasaki disease.

Noninvasive assessment of the early progression of atherosclerosis in adolescents with Kawasaki disease and coronary artery lesions

OBJECTIVES

The severity of carotid arteriosclerosis, defined as increased intima-media thickness (IMT) visible with B-mode ultrasound, is correlated with risk factors for coronary heart disease. Little is known, however, about the relation of IMT, the stiffness of the common carotid artery, and the progression of atherosclerosis in children with Kawasaki disease (KD) and coronary artery lesions (CAL).

DESIGN

We investigated the associations among total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglyceride, TC/HDL-C, ApoE genotype, glycohemoglobin, IMT, and arterial stiffness by high resolution ultrasound in 20 adolescents with KD and CAL (age: 16.6 +/- 4.1 years, males: 60%) and 20 sex- and age-matched healthy controls (Cont).

RESULTS

No significant differences were observed in the values of body mass index and blood pressure between the 2 groups. Also no significant differences were observed in the levels of TC, LDL-C, HDL-C, triglyceride, TC/HDL-C within normal values, or the allele frequency of Apo E4 between the 2 groups. However, the values of IMT, stiffness, and glycohemoglobin in patients with KD were significantly higher than those in Cont (0.53 +/- 0.07 vs 0.46 +/- 0.05 mm, P <.05; 4.11 +/- 0.86 vs 2.94 +/- 0.91, P <.001; 5.0 +/- 0.4 vs 4.6 +/- 0.2%, P <.05). A significant relationship was observed between sex and the mean IMT (r = 0.46) in Cont; however, no significant correlation was found between mean IMT and other variables in either group. Although the arterial stiffness was strongly related to body mass index (r = 0.58) and systolic blood pressure (r = 0.55) in Cont, no significant relationship was observed between the stiffness and any variable tested in patients with KD.

CONCLUSIONS

The less distensible carotid wall in patients with KD compared with that in Cont without major alteration of the lipid profile is likely to be secondary to the changes in arterial walls after a diffuse vasculitis involving noncoronary arteries. These results indicate that the coronary arteries may be predisposed to accelerated atherosclerosis in patients with KD and CAL.

[Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging]

OBJECTIVES

Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5 +/- 6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease.

METHODS

Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR).

RESULTS

The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33 +/- 0.22 in chronic heart failure class I, 2.50 +/- 0.34 in class II, 1.95 +/- 0.61 in class III, and 1.39 +/- 0.29 in class IV (p < 0.05). %WR was 24.8 +/- 12.8% in chronic heart failure class I, 23.3 +/- 10.2% in class II, 49.2 +/- 24.5% in class III, and 66.3 +/- 26.5% in class IV (p < 0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure.

CONCLUSIONS

Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure.

Relationship between fat distribution and lipid and apolipoprotein profiles in young teenagers

The influence of obesity and fat distribution on serum levels of lipoprotein and apolipoprotein was investigated in 294 Japanese junior high school children (12-13 years of age). Serum levels of low-density lipoprotein cholesterol (LDLC) (P = 0.013), triglycerides (TG) (P = 0.0006), and apolipoprotein B (apoB) (P = 0.003), and the apoB/A-I ratio (P = 0.005) were significantly higher and serum levels of high-density lipoprotein cholesterol (HDLC) (P = 0.00003) and apoA-1(P = 0.003) were significantly lower in obese boys than in non-obese boys. The serum levels of TG (P = 0.013) and the apoB/A-I ratio (P = 0.011) were significantly higher and the serum levels of HDLC (P = 0.004) was significantly lower in obese girls than in non-obese girls. The LDLC/apoB ratio was lower in obese girls than in non-obese girls (P = 0.03). Obesity (> or = 20% of ideal weight) was strongly correlated with the serum levels of lipids and apolipoproteins in boys; this relationship was less clear in girls. The degree of obesity and the body mass index (BMI) were more strongly correlated with serum levels of lipids and apolipoproteins in boys than in girls. In boys, atherogenic lipoproteins and apolipoproteins, such as LDLC and apoB, showed a stronger correlation with the thickness of the triceps skinfold, while in girls the anti-atherogenic lipoproteins and apolipoproteins, such as HDLC and apoA-I, showed a stronger correlation with both the triceps and the subscapular skinfold thicknesses. In girls the relationships between the BMI and the degree of obesity and the thickness of the subscapular skinfold (S) thickness were similar to the relationships between those parameters and the triceps skinfold (T) thickness. In boys, these parameters showed a stronger correlation with the subscapular skinfold thickness than with the triceps skinfold thickness. The correlation coefficients for the relationships between skinfold thickness and lipid and apolipoprotein levels were similar to the coefficients for the relationships between skinfold thicknesses and the severity of obesity and the BMI. The distribution of central-type fat accumulation, which is indicated by the thickness of the subscapular skinfold, the S/T ratio and S-T value, was inversely correlated with the HDLC level in both boys and girls. The degree of obesity was strongly correlated with the atherogenic lipoprotein profile in boys, in part because the subscapular skinfold thickness was strongly correlated with the degree of obesity and the BMI. In girls, the correlations between indices of central-type obesity and atherogenic lipid and apolipoprotein profiles were stronger than in boys. These data suggest that childhood obesity may be an early cardiovascular risk factor.

Measurement of coronary flow reserve in children by transthoracic Doppler echocardiography

Noninvasive measurement of coronary flow reserve was performed by transthoracic color Doppler echocardiography in 28 children with Kawasaki disease.

[Optimum protocol of technetium-99m tetrofosmin myocardial perfusion imaging for the detection of coronary stenosis lesions in Kawasaki disease]

The clinical usefulness of a new myocardial perfusion imaging agent, technetium-99m tetrofosmin, was assessed in 58 patients for a total of 76 times (mean age 9.7 years, 1-15 years) including 20 with and 26 without significant coronary stenotic lesions in Kawasaki disease. Pharmacological (dobutamine or adenosine triphosphate disodium) or exercise stress technetium-99m tetrofosmin single photon emission computed tomography was performed under stress and at rest on the same day. The sensitivity for detection of stress-induced perfusion defects by this method was 90% (18/ 20) and the specificity was 85% (22/26). The dose was 9.3 +/- 2.5 MBq/kg under stress and 18.7 +/- 5.6 MBq/kg at rest. No significant correlation was recognized between the dose and the image quality. Adequate image quality was provided by projection time 20-40 sec per frame. Increased liver accumulation was seen in 24% (18/76), especially in younger and pharmacological stress cases. The acquisition starting time after tetrofosmin injection was 58.4 +/- 18.7 min in the negative increased liver accumulation group and 43.7 +/- 18.3 min in the positive group (p < 0.01). We recommend that the following protocol is used for pediatric imaging. 1) The standard tetrofosmin dose is rougly 10 MBq/kg (upper limit 370 MBq) at stress and the double dose for the rest imaging. 2) SPECT projection time of 20-40 sec per frame. 3) In practice, the patient should be fasting prior to stress injection, and the imaging should be done 1 hour after eating. The rest injection should be done immediately thereafter, and the rest image should be obtained 1 hour later.

A case of Guillain-Barré syndrome accompanied by sympathetic overactivity and hypertensive encephalopathy

Hypertension has often been observed in patients with Guillain-Barré syndrome, and various underlying mechanisms have been implicated. We report the case of a child with the Guillain-Barré syndrome whose hypertension was associated with increases in both renin activity and circulating catecholamines. This case also appeared to be complicated by hypertensive encephalopathy. Following administration of intravenous regitine, a blood pressure change was observed and cardiac performance was assessed by two-dimensional echocardiography. Results indicated that increased total peripheral resistance may have been responsible for the symptoms and the hypertension. The hypertension was effectively managed by nifedipine, captopril and prazosin without the need for beta-blockade.

Dobutamine stress echocardiography for detection of coronary artery stenosis in children with Kawasaki disease

OBJECTIVES

This study was designed to assess the feasibility and diagnostic accuracy of dobutamine stress echocardiography for detection of coronary artery stenosis in children with Kawasaki disease.

BACKGROUND

Dobutamine stress echocardiography is valuable as an alternative test for detection of coronary artery disease in adult patients; however, its usefulness for children has been demonstrated only in limited cases.

METHODS

Dobutamine stress echocardiography (up to 30 microgram/kg body weight per min) was performed in 50 patients at the convalescent stage of Kawasaki disease, including 26 patients with coronary sequelae documented by previous coronary angiography (sequelae group, 3 to 15 years old) and 24 patients with normal coronary arteries documented by echocardiography (normal group, 7 to 16 years old), who underwent quantitative coronary angiography on a separate day. Left ventricular regional wall motion divided into 16 segments was assessed in relation to the extent of coronary artery disease. A positive test response was defined as a new or worsened wall motion abnormalities.

RESULTS

Significant coronary artery disease (> or = 50% diameter stenosis of major vessels) was present in 21 patients in the sequelae group. There was no significant difference in the maximal dose of dobutamine between the sequelae and normal groups ([mean +/- SD] 22.4 +/- 5.1 vs. 24.2 +/- 2.5 microgram/kg per min). Heart rate and systolic blood pressure were significantly increased (p < 0.01) at maximal dose of dobutamine compared with values at rest in both groups; consequently, the rate-pressure product exceeded 20,000 in 20 (40%) of the 50 patients during dobutamine infusion. Ten patients had self-limiting side effects; however, there were no serious complications from stress-induced ischemia. New wall motion abnormalities corresponding to the extent of coronary artery disease were detected in 19 of 21 patients in the sequelae group, whereas no wall motion abnormalities were detected in the normal group. Thus, the sensitivity and specificity of dobutamine stress echocardiography for the detection of coronary artery disease were 90% and 100%, respectively.

CONCLUSIONS

We conclude that dobutamine stress echocardiography is a safe and accurate diagnostic method for detection of coronary artery stenosis in Kawasaki disease. Moreover, this is a possible alternative method for patients unable to exercise adequately, even if they are small children.

[An operative case of solitary interruption of the aortic arch in adult]

A 43-year-old lady was hospitalized due to easy fatiguability in the legs during exercise, and for evaluation of an abnormal shadow in the chest X-ray, and hypertension. Her blood pressure was 200/80 mmHg in the right arm, 140/70 mmHg in the left, and 110/70 mmHg in both lower extremities. Systolic vascular bruit radiating to her neck and back was audible in the Erb's area. DSA and aortogram disclosed extremely dilated vessels around the origin of the left common carotid artery. The left subclavian artery was opacified retrogradely as a subclavian blood steal via the left vertebral artery, and mild stenosis was seen at its origin. There was no evidence of associated congenital anomaly such as VSD, PDA, or ASD. The final diagnosis, solitary interruption of the aortic arch (S-IAA, type B), was made by MRI. The patient had an extra-anatomical bypass operation by using Cooley woven dacron graft from the ascending to the abdominal aorta. The result was good. S-IAA is a very rare congenital anomaly. As far as we know, only 21 patients with S-IAA including this case have been reported. A physician should be aware that a patient with S-IAA tends to have a difference of blood pressure not only between the upper and lower extremities but also between both arms, and pressure in the right arm is usually higher than that in the left. These are good signs to suspect S-IAA. And they also can be helpful to differentiate S-IAA from coarctation of the aorta.

[A case of acute myocardial infarction due to coronary embolism from left atrial thrombus with atrial fibrillation]

A 55-year-old man, who has been on follow-up observation with chronic atrial fibrillation, came in with a sudden onset of chest pain on July 31, 1986. He was diagnosed as having acute myocardial infarction indicated by abnormal ECG, elevated serum enzyme and characteristic signs of echocardiography. Emergency coronary angiography was performed 2 hours after the onset of chest pain, and it was reported as showing total obstruction of the distal left anterior descending artery. Percutaneous transluminal coronary recanalization using 1,200,000 units of urokinase was unsuccessful. The repeated angiography performed 40 days later, showed normal coronary arteriogram, but left ventriculogram revealed akinesis of the apical segment. Furthermore, left atrium opacified in the levophase of pulmonary arteriogram indicated left atrial thrombus. The cause of the myocardial infarction was considered to be coronary embolism from the left atrial thrombus with atrial fibrillation. It must be the first report documented by coronary angiography, of coronary thrombo-embolism due to chronic atrial fibrillation without any underlying disease.

Follow-up results of surgical treatment for chronic pancreatitis. Present status in Japan

The results of surgical treatment for chronic pancreatitis at our clinic and in the eight leading institutions of Japan were reviewed in a total of 328 cases. Abdominal pain disappeared or was alleviated in about 90 percent of the patients who survived more than 6 months after operation. There was no significant differences in the effect of pain among the three main types of operations: pancreaticoduodenectomy, distal resection and pancreatic ductal drainage. In the collected cases, however, complete disappearance of pain was reported more often in patients subjected to Puestow's operation than in those who underwent Nardi's operation. The patients who underwent pancreatic ductal drainage had a greater postoperative weight gain than those without drainage, in both our patients and the collected cases. In the collected cases, Puestow's operation was predominantly linked to postoperative weight gain. Evidence of pancreatic functional improvement, either in endocrine or in exocrine, was very meager.

Studies on porcine pancreatic elastase activity. II. Immunoreactive elastase level during acute hemorrhagic pancreatitis in pigs

Acute hemorrhagic pancreatitis was produced in pig to study serum concentration of elastase and its physiological role. Pancreatitis was induced in two groups of young pigs by the injection of autologous bile. One group was injected with autologous bile (0.5 ml/kg) at high pressure, and the second group was injected as low pressure (100 cm H2O). Then femoral blood, portal blood and thoracic lymph were sampled at scheduled time intervals. The control level of immunoreactive elastase was around 90 ng/ml in each site, which significantly increased beginning 15 min after bile injection; the level of immunoreactive elastase was higher in the thoracic lymph duct than in the femoral and portal vein. The total and free elastase of both groups in pancreatic tissue were significantly decreased in pancreatitis, and an abundance of immunoreactive elastase was found in the ascites. The increasing pattern of immunoreactive elastase and amylase after bile injection was very similar. Therefore, the level of immunoreactive elastase was considered to be inadequate to determine the grade of severity of pancreatitis as well as the level of amylase which is already known.

Studies on porcine pancreatic elastase activity. I. Radioimmunoassay of porcine pancreatic elastase

An improved method of radioimmunoassay was devised to offer a successful formula for determining blood concentration of elastase. With porcine pancreatic elastase as the antigen, rabbits were immunized to obtain antiserum. Iodinated elastase labeled by the chloramine-T procedure using 131I (or 125I) had a specific activity of 200-300 mCi/mg. The double antibody method was used for BF separation. While the usual method of radioimmunoassay was not always successful in obtaining accurate serum concentration of elastase, the use of diisopropyl fluorophosphate (DFP) was able to eliminate the disturbing influence of intra-serious inhibitors, alpha 1-AT and alpha 2-M, eventually producing satisfactory results. With the use of DFP, the elastase standard curve and the porcine serum dilution curve had a statistically significant correlation; precision and recovery were both satisfactory; cross-reactivity of the antiserum with trypsin and chymotrypsin was less than 0.001%. The minimal detectable concentration of elastase was 5 ng/ml, and the range of normal fasting porcine serum level was 70-100 ng/ml.

Effects of eight amino acids on the exocrine and endocrine pancreatic function

Eight amino acids were intravenously administered in a dose of 2 mmoles/kg/hr to dogs with chronic pancreatic fistula, and the effect of each amino acid on endocrine and exocrine pancreatic secretions was investigated. Asparagine, arginine, isoleucine and phenylalanine administered under the stimulation of secretin-pancreozymin significantly inhibited the secretion of pancreatic juice by 23%, 15%, 13% and 13%, and the output of amylase by 53%, 37%, 27% and 18%, respectively. Threonine, glycine or methionine brought about no significant changes in pancreatic secretion, but valine significantly increased pancreatic juice secretion by 13% and amylase output by 15%. Any of the eight amino acids caused no noticeable change in the concentration of bicarbonate.

Factors influencing the late results of operation for carcinoma of the pancreas

In 151 patients with carcinoma of the pancreas presenting at the surgical clinic of Tohoku University Hospital, predominant factors affecting postoperative prognosis were studied with relation to the stages of the disease. The presence of lymph node metastasis and of cancer invasion to the pancreatic capsule, particularly the latter, was apparently a significant factor most crucially affecting the survival of the patients who underwent pancreatoduodenectomy. The mean survival periods of resected patients were 16.4 months for those with carcinoma of the head of the pancreas and 11.0 months for those with carcinoma of the body and tail of the pancreas, distinctly longer than after palliative operations. However, in patients with stage III disease, pancreatoduodenectomy tended to lead to a shorter period of survival, suggesting that surgery at that stage is generally unpromising for cure.

Effects of hypertonic glucose and amino acid infusions on pancreatic exocrine function

Inhibiting effects of hypertonic glucose and amino-acids on pancreatic exocrine function were studied using mongrel dogs with chronic gastric and pancreatic fistulae. Under the basal stimulation with secretin and pancreoxymin, 20% glucose, 30% glucose and 12% amino acids were given intravenously. Infusion of these substances caused the maximal decreases in pancreatic juice volume and amylase output, to 23% and 11%, respectively (20% glucose), 32% and 29% (30% glucose), and 53% and 42% (12% amino acids). But no significant changes were noted in bicarbonate concentration. When glucose was infused, the rise in levels of blood sugar and IRI was associated with the inhibition of pancreatic exocrine secretion. Aminoacid infusion produced the greatest inhibitory effect on the pancreatic secretion and markedly elevated both the levels of IRI and IRG. Intravenous infusion of glucagon suppressed notably the exocrine function of the pancreas.

Follow-up studies of radical resection for pancreaticoduodenal cancer

In a study of 66 patients with pancreaticoduodenal cancer with pancreaticoduodenectomy, there were five (7.5%) hospital deaths. Five-year survival rates were 7.8% in 20 patients with carcinoma of the head of the pancreas, 16.7% in 31 patients with carcinoma of the bile duct, and 38.5% in 15 patients with carcinoma of the ampulla of Vater. Fecal fat loss measured was 10 g or less per day in nine of 12 patients. Of the 19 patients having glucose tolerance tests, 13 showed abnormalities including the two who were diabetic. Operative findings which were indicative of a poor prognosis included lymph node metastases, macroscopic invasion of the tumor into the pancreatic capsule in patients with carcinoma of the head of the pancreas, the size of the tumor in those with carcinoma of the common bile duct, and direct invasion of the lesion into the pancreas in patients with carcinoma of the ampulla of Vater.

Parotid saliva tests in patients with pancreatic diseases before and after surgery

Two patients with pancreatic cyst were treated by cystojejunostomy, two others with pancreaticolithiasis by pancreaticojejunostomy (side to side), and pancreato-duodenectomy was done in one patient with cancer of the duodenal papilla and in one patient with cancer of the intrapancreatic bile duct. All these patients made uneventful recovery. In all these cases, parotid gland function was found depressed. After the operation, four patients showed normal parotid gland function and in one patient it was abnormally elevated. Thus, as previously reported in animal experiments, the parotid gland function was presumed to return to normal or to be elevated in parallel with the improvement of the pancreatic function or lesions.

Appraisal of operative treatment for chronic pancreatitis. With special reference to side to side pancreaticojejunostomy

A total of sixty-one operations were performed in sixty of seventy-one patients with chronic pancreatitis, with the following results. 1. The procedures used were side to side pancreaticojejunostomy in twenty-four patients, caudal pancreatectomy in ten, pancreaticoduodenectomy in six, total pancreatectomy in one, removal of pancreatic calculi in four, cystojejunostomy in two, biliary tract procedures in twelve, and drainage of pancreatic abscess in one. Operative fatality occurred in six patients, with fifty-four surviving operation. 2. Of fifty-three patients surviving operation (excluding the one who underwent only exploratory laparotomy), forty-seven (88 per cent) had relief of pain. With the exception of two patients with complicating cancer of the pancreas at the time of operation, of fifty-two patients surviving operation, thirty-nine (75 per cent) had satisfactory results at follow-up study. 3. Sixteen of twenty-four patients (66.7 per cent) undergoing side to side pancreaticojejunostomy had satisfactory follow-up results. 4. Comparison of pre- and postoperative body weight levels in twenty-one patients undergoing side to side pancreaticojejunostomy showed a postoperative loss of less than 10 per cent in seven, unchanged weight in two, and a gain in eleven patients, including five with more than 10 per cent gain. However, fat absorption examination in these patients showed no distinct postoperative improvement in digestion and absorption. 5. Histologic evidence in one patient at autopsy four years and eleven months after side to side pancreaticojejunostomy indicated improvement in fibrosis of the pancreas as compared with the findings at operation.