[Augmented antitumor activity in combination chemotherapy of nedaplatin with etoposide]

Augmented antitumor activity in combination chemotherapy of Nedaplatin (NDP) or Cisplatin (CDDP) with Etoposide (ETP) against murine and human lung cancer cells was demonstrated. NDP and CDDP were administered once and ETP daily for five days via tail vein. In the mice bearing Lewis lung carcinoma, a combination of NDP and ETP resulted in synergistically enhanced inhibition of tumor growth, and prolonged survival in comparison with either NDP or ETP alone. NDP showed a more potent combination effect with ETP than CDDP did. These effects were also demonstrated in human lung cancer cell lines. Although body weight loss was enhanced by the combination of NDP or CDDP with ETP, it was tolerable, and no significant difference between NDP plus ETP and CDDP plus ETP was observed. Thrombocytopenia was not enhanced in the combined treatment of NDP with ETP. These results suggest the usefulness of the combination of NDP with ETP as a clinical therapy for lung cancer.

Synergy of the combination of nedaplatin with etoposide in murine and human lung carcinoma

BACKGROUND

The combination of cisplatin (CDDP) and etoposide (ETP) has been shown to be an effective treatment for lung cancer. Nedaplatin (NDP) has been developed as a second generation plainum complex. Because of its superior antitumor activity and lower nephrotoxicity in comparison with CDDP, the antitumor effects of NDP in combination with ETP against murine and human lung cancer was investigated.

MATERIALS AND METHODS

Lewis murine lung carcinoma, RERF-LC-AI, and Ma44 human lung cancer were used in this study. NDP (1/4 to 1 maximum to related dose; MTD) and CDDP (1/4 to 1 MTD) were administered once and ETP (1/32MTD) was administered daily for five days via the tail vein of mice.

RESULTS

In the mice bearing Lewis lung carcinoma, a combination of NDP and ETP resulted in synergistically enhanced inhibition of tumor growth (Treated/Control ratio; T/C = 0.001) in comparison with either NDP or ETP alone (T/C = 0.12 for NDP, T/C = 0.13 for ETP), and prolonged survival (Increased Life Span; ILS% > or = 172) in comparison with either NDP or ETP alone (ILS% = 65 for NDP, ILS% = 54 for ETP). NDP showed a more potent combination effect with ETP than CDDP did for both growth inhibition and survival. This effect was confirmed in human lung cancer. Although body weight loss was enhanced by the combined treatment, it was tolerable. With regards to myelosuppression, no significant difference between NDP plus ETP and CDDP plus ETP was observed.

CONCLUSION

These results suggest the superiority of a combination of NDP with ETP against CDDP with ETP as a clinical therapy for lung cancer.

Hydroxyurea can be used to increase mouse c-kit+Thy-1. 1(lo)Lin-/loSca-1(+) hematopoietic cell number and frequency in cell cycle in vivo

The DNA synthesis inhibitor hydroxyurea (HU) was administered to determine whether it induces changes in the cell-cycle status of primitive hematopoietic stem cells (HSCs)/progenitors. Administration of HU to mice leads to bone marrow accumulation of c-kit+Thy-1.1(lo)Lin-/loSca-1(+) (KTLS) cells in S/G2/M phases of the cell cycle. HU is a relatively nontoxic, reversible cell-cycle agent that can lead to approximately a threefold expansion of KTLS cells in vivo and approximately an eightfold increase in the number of KTLS cells in S/G2/M. HSCs in HU-treated mice have undiminished multilineage long-term and short-term clonal reconstitution activity.

A case of Klippel-Trenaunay syndrome associated with Huntington's disease

We report here on a patient with Klippel-Trenaunay syndrome who was later diagnosed with Huntington's disease. Consistent with the later diagnosis, a (CAG)n repeat longer than the normal range was observed on chromosome 4p. The presence of these two diseases in the same individual may represent coincidence or a true correlation which must be confirmed by other evidence. To our knowledge, this is the first published report of the concurrent presence of these diseases in the same individual.

Endoscopic lithotomy of common bile duct stones with sublingual nitroglycerin and guidewire

OBJECTIVE

In 21 patients, our objective was the endoscopic removal of common bile duct stones by sphincter dilation with the application of sublingual nitroglycerin.

METHODS

Nitroglycerin 0.3-0.6 mg was needed for proper dilation of the orifice and for successful cannulation of the Dormia basket into the bile duct. Cannulation of the Dormia basket was simplified by placing the guidewire in the common bile duct beforehand. Because of possible stone impaction, a mechanical lithotriptor was applied smoothly in two patients.

RESULTS

Complete stone removal was successful in 18 of the 21 (86%) patients. One patient who developed a mild form of acute pancreatitis recovered in a few days by conservative management with drip infusion of protease inhibitor. Blood pressure dropped transiently in a patient receiving nitroglycerin, but the general condition of the patient was stable.

CONCLUSIONS

This procedure was found to be safe, easy, and effective in extracting common bile duct stones.

[Short-term results of leaving elephant trunk in type A aortic dissection]

Elephant trunk prosthesis was devised for treatment of multiple aortic aneurysm. But it has applied to type A aortic dissection. Because residual false lumen often dilates gradually and come to have the risk of rupture. Two patients who were diagnosed as type A aortic dissection were performed total aortic arch replacement with Elephant trunk prosthesis on distal anastmosis. Postoperative diagnostic images showed that residual false lumen of proximal descending aorta were thrombosed. Now it is not necessary to perform next extensive aortic replacement. Complication which is threatened in using Elephant trunk prosthesis, paraplegia, thromboembolism, kinking of prosthesis could have been avoided by setting suitable length and diameter of the prosthesis.

[Early and late results of replacement of the ascending aorta and/or aortic arch using selective cerebral perfusion]

From 1987 to 1994, 116 patients received replacement of the ascending and/or aortic arch using selective cerebral perfusion. They were 82 male and 34 female, with average age of 64 years. There were 63 dissecting and 53 true aneurysms. Extent of replacement was: ascending aorta in 13, aortic root in 2, aortic arch in 93, and aortic root and complete arch in 8. Aortic arch replacements were composed of: 29 partial proximal aortic arch replacements, 44 complete aortic arch replacements, and 20 partial distal aortic arch replacements. Nineteen (16.4%) hospital deaths occurred. Univariate testing of pre-, intra-, and post-operative variables followed by stepwise logistic regression analyses identified elderly, ischemic heart disease, postoperative neurologic complication, cardiac dysfunction, renal failure, and massive bleeding as factors having independent association with hospital mortality. Neurologic complication was found in 10 patients (8.6%), and risk factor for this complication was preoperative peripheral vascular disease. Follow-up of hospital survivors documented an overall cumulative 5-year survive rate of 69%. There was no significant difference between dissection and true aneurysms in 5-year survive ratios, which were 63% and 82%, respectively. During follow-up periods, 18 patients died. Half of these cases were vascular deaths, caused by rupture, sudden death and secondary operation. Univariate analyses followed by stepwise Cox testing indicated that chronic obstructive pulmonary disease and a history of postoperative massive bleeding were associated with decreased later survival. Our experience suggests that selective cerebral perfusion is a safe technique for the repair of ascending aorta and/or aortic arch problems. High-risk subgroups of patients with these aortic problems can be identified by risk factors. Aggressive and careful management is necessary for such subgroups to improve early and late survival rates.

[A case of left atrial thrombi following mitral valvuloplasty for mitral regurgitation associated with idiopathic thrombocytopenic purpura]

A 58-year-old man, who had been submitted to an indication of mitral valvuloplasty (MVP) because of severe mitral regurgitation, was diagnosed as idiopathic thrombocytopenic purpura (ITP). In order to diminish the peri-operative blood loss, splenectomy and high-dose bolus administration of gamma-globulin (400 mg/kg/day) were performed at the time of two weeks and during last five days respectively, prior to MVP surgery. In early post-operative stage, anticoagulant therapy was held down considering ITP, and we were not troubled with bleeding throughout the peri-operative period. On the fourteenth post-operative day, however, mural thrombi in the left atrium were pointed out by transesophageal echocardiography (TEE). Then anticoagulant therapy was reinforced by increasing the warfarin dose. When TEE was restudied on 36th, post-operative day, mural thrombi had almost disappeared. Although it is commonly known that mitral valvuloplasty has low risk of thrombosis and less necessity of anticoagulation, hyper coagulability may be feasible in the early post-operative period of our case whose ITP is meticulously treated prior to surgery. Suitable anticoagulation should have been performed regardless of ITP immediately after MVP.

New age-adjusted measure of body fat distribution in children and adolescents: standardization of waist-hip ratio using multivariate analysis

OBJECTIVE

To explore a new anthropometric index of body fat distribution adjusted for ages ranging from 6-15 y in both boys and girls.

DESIGN

Sex, age, and 11 anthropometric variables were subjected to principal component analysis. Based on these results, we developed a new anthropometric index, namely an age-adjusted measure of body-fat distribution. This index was evaluated statistically for suitability of use in epidemiological surveys.

SUBJECTS

Japanese children, including obese and nonobese subjects, in one elementary and one junior high school in Yamanashi Prefecture, Japan: 508 boys and 549 girls whos ages ranged from 6 y 1 mon-15 y.

MEASUREMENTS

Measurements included the height (Ht), body weight, circumference of the waist, hip and thigh. Body mass index, the ratios of the waist, hip or thigh to the Ht, waist-hip ratio (WHR) and waist-thigh ration were calculated.

RESULTS

The first principal component (PC 1) accounted for 49.8% of the total variation, and was interpreted as an indicator of the general size on an individual. PC 2 accounted for 25.9%, and was interpreted as a shape measure that indicates body fat distribution. Calculation of WHR/Ht, a parameter that represented PC 2 adjusted by PC 1, gave an highly robust linear regression equation for age by gender. The residuals from the regression line for WHR/Ht deviated from normal distribution only in the boys, whereas the mean residual was nearly zero and distribution of the residuals was similar in three age subgroups by gender, supporting the use of the common standard deviation score in all age groups as an indicator of body fat distribution.

CONCLUSION

The common standard deviation score of WHR/Ht can serve as an epidemiological index of body fat distribution adjusted for ages between 6 and 15 y.

From stem cells to lymphocytes: biology and transplantation

We review the development of the hematopoietic system, focusing on the transition from hematopoietic stem cells (HSCs) to T cells. This includes the isolation of HSCs, and recent progress in understanding their ontogeny, homing properties, and differentiation. HSC transplantation is reviewed, including the kinetics of reconstitution, engraftment across histocompatibility barriers, the facilitation of allogeneic engraftment, and the mechanisms of graft rejection. We describe progress in understanding T-cell development in the bone marrow and thymus as well as the establishment of lymph nodes. Finally, the role of bcl-2 in regulating homeostasis in the hematopoietic system is discussed.

Photoreactivating enzyme for (6-4) photoproducts in cultured goldfish cells

We previously reported that when cultured goldfish cells are illuminated with fluorescent light, photorepair ability for both cyclobutane pyrimidine dimers and (6-4) photoproducts increased. In the present study, it was found that the duration of the induced photorepair ability for cyclobutane pyrimidine dimers was longer than that for (6-4) photoproducts, suggesting the presence of different photolyases for repair of these two major forms of DNA damage. A gel shift assay was then performed to show the presence of protein(s) binding to (6-4) photoproducts and its dissociation from (6-4) photoproducts under fluorescent light illumination. In addition, at 8 h after fluorescent light illumination of the cell, the binding of protein(s) to (6-4) photoproducts increased. The restriction enzymes that have recognition sites containing TT or TC sequences failed to digest the UV-irradiated DNA photoreactivated by using Escherichia coli photolyase for cyclobutane pyrimidine dimers, indicating that restriction enzymes could not function because (6-4) photoproducts remained in recognition sites. But, when UV-irradiated DNA depleted of cyclobutane pyrimidine dimers was incubated with extract of cultured goldfish cells under fluorescent light illumination, it was digested with those restriction enzymes. These results suggested the presence of (6-4) photolyase in cultured goldfish cells as in Drosophila, Xenopus and Crotalus.

The characterization, molecular cloning, and expression of a novel hematopoietic cell antigen from CD34+ human bone marrow cells

The adhesion molecule BEN/SC1/DM-GRASP (BEN) is a marker in the developing chicken nervous system that is also expressed on the surface of embryonic and adult hematopoietic cells such as immature thymocytes, myeloid progenitors, and erythroid progenitors. F84.1 and KG-CAM, two monoclonal antibodies to rat neuronal glycoproteins with similarity to BEN, cross-react with an antigen on rat hematopoietic progenitors, but F84.1 only also recognizes human blood cell progenitors. We have defined the antigen recognized by F84.1 as the hematopoietic cell antigen (HCA). HCA expression was detected on 40% to 70% of CD34+ fetal and adult bone marrow cells and mobilized peripheral blood cells. Precursor cell activity for long-term in vitro bone marrow cell culture was confined to the subset of CD34+ cells that coexpress HCA. HCA is expressed by the most primitive subsets of CD34+ cells, including all rhodamine 123(lo), Thy-1+, and CD38(-/lo) CD34+ adult bone marrow cells. HCA was also detected on myeloid progenitors but not on early B-cell progenitors. We also describe here the cloning and characterization of cDNAs encoding two variants of the human HCA antigen (huHCA-1 and huHCA-2) and of a cDNA clone encoding rat HCA (raHCA). The deduced amino acid sequences of huHCA and raHCA are homologous to that of chicken BEN. Recombinant proteins produced from either human or rat HCA cDNAs were recognized by F84.1, whereas rat HCA but not human HCA was recognized by antirat KG-CAM. Expression of either form of huHCA in CHO cells conferred homophilic adhesion that could be competed with soluble recombinant huHCA-Fc. The molecular cloning of HCA and the availability of recombinant HCA should permit further evaluation of its role in human and rodent hematopoiesis.

[Single-stage correction of coarctation of the aorta with aortic regurgitation]

A successful single-stage correction of coarctation of the aorta with aortic regurgitation is reported. A 39-year-old man was referred for angina, ankle swelling, and numbness of lower extremities. Aortogram revealed severe aortic regurgitation and coarctation of the aorta with 2.8 mm minimum diameter. Aortic valve replacement was performed under separate perfusion of upper and lower body, after which the coarctectomy and graft interposition were done under the left heart bypass. The patient was discharged in good condition with minor medication of digitalis and anticoagulant agents. As far as the case is concerned, the left heart bypass during graft interposition has possible risk of cardiac arrest and usual cardiopulmonary bypass is hazardous when complicated by severe coarctation of the aorta. Surgical procedure and assist methods used in this case were quite useful for coarctation of the aorta with aortic regurgitation.

Increased plasma cholesteryl ester transfer activity in obese children

To determine whether enhanced activity of cholesteryl ester transfer protein (CETP) contributes to the development of atherogenic lipoprotein profiles in obese children, plasma CETP activity was assayed according to a micro-method, by co-incubating lipoprotein-deficient samples with exogenous donor and acceptor lipoproteins. The study subjects were 31 obese children (14 males and 17 females). Serum levels of triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), TC:high-density lipoprotein (HDL)-C, LDL-C:HDL-C, apolipoprotein (apo) B, and apo B:apo Al were increased in obese children. Thus they appeared to exhibit an atherogenic lipoprotein profile, with a relative decrease in cholesterol carried by HDL compared with the cholesterol in the other lipoprotein fractions. The mean fasting plasma insulin level was also increased. CETP activity was significantly higher in the obese children than in nonobese control children, and was correlated with LDL-C, TC:HDL-C, LDL-C:HDL-C, and apo B:apo Al. These results suggest that an increase in plasma CETP activity results in atherogenic change in lipoprotein metabolism in obese children. The increase in CETP may be due to the adiposity or insulin resistance. Alternatively, dyslipidemia per se, physical inactivity or excessive fat intake, that are commonly found in obese children, may contribute to the increase in CETP activity.

[Foscarnet therapy for ganciclovir-refractory cytomegalovirus hepatitis in a patient who underwent bone marrow transplantation from an unrelated donor]

Cytomegalovirus (CMV) hepatitis refractory to ganciclovir treatment occurred after prolonged administration of ganciclovir in a 36-year-old woman with chronic myelogeneous leukemia who had undergone allogeneic bone marrow transplantation (BMT) from an HLA-identical unrelated donor. The number of CMV antigen-positive leukocytes in blood were well correlated with the serum levels of transaminases and the antigenemia assay was useful in monitoring CMV hepatitis. The patient was treated with foscarnet, a potent inhibitor of CMV DNA-polymerase, which led to rapid improvement of the CMV antigenemia and the transaminase concentrations. Foscarnet therapy should be considered for ganciclovir-resistant CMV disease in the setting of BMT.

The unexpected G0/G1 cell cycle status of mobilized hematopoietic stem cells from peripheral blood

Treatment with a combination of cytokines and chemotherapy can effectively stimulate the release of hematopoietic stem cells (HSC) into the peripheral blood (PB), which can then be harvested for transplantation. The cell cycle status of the harvested HSC from mobilized PB (MPB) is of interest because of the impact that cell cycling may have on optimizing the conditions for ex vivo expansion, retrovirus-mediated gene transfer, and the engraftment of transplanted tissues. Therefore, we characterized the cell cycling status of mobilized HSC from mice and humans. The murine HSC, which express the phenotype c-kit+ Thy-1.1lo Lin-/lo Sca-1+, were purified from PB, bone marrow (BM), and spleen after the mice were treated with the mobilizing regimen of granulocyte colony-stimulating factor (G-CSF) or a combination of cyclophosphamide (CTX) and G-CSF. Human HSC (CD34+ Thy-1+ Lin-) and progenitor cells (CD34+ Thy-1-Lin-) were isolated from the BM of untreated healthy volunteers and from MPB of healthy volunteers and patients treated with G-CSF or a combination of CTX and GM-CSF. Cell cycle status was determined by quantitating the amount of DNA in the purified cells after staining with the dye Hoechst 33342. Fluorescence-activated cell sorting analysis of the progenitor cells from the murine and human samples showed an unexpected finding, ie, virtually none of the cells from the MPB was cycling. The G0/G1 status of HSC from MPB was surprising, because a significant proportion of HSC from BM are actively proliferating and, after mobilization, the HSC in the spleen and BM were also actively cycling.

Increased phospholipase D activity in human breast cancer

Phospholipase D is believed to play an important role in cell proliferation and tumorigenesis. One of its major functions is to cause a sustained activation of protein kinase C through the primary production of phosphatidic acid from phosphatidylcholine by the enzyme, followed by dephosphorylation forming diacylglycerol. Protein kinase C is known to be activated or translocated in some tumors including breast tumors. In order to examine phospholipase D activity in breast tumors, surgical specimens of human breast tumors were obtained by mastectomy or wide excision, and their phospholipase D activities were assayed by determining the formation of phosphatidylethanol from phosphatidylcholine and ethanol. Phospholipase D activity was predominantly localized in the microsomal fraction of the tumor tissue and markedly stimulated by oleic acid. We observed a significant increase in phospholipase D activity in 17 out of 19 spontaneous human breast tumors as compared to adjacent histologically normal breast tissue. The mean specific activity in the tumors was 52.9 +/- 41.8 (SD) pmol min-1 mg protein-1 whereas the value for the normal breast tissue was 34.0 +/- 36.2 (SD) pmol min-1 mg protein-1 (P < 0.01; paired Wilcoxon's rank-sum test). The mean tumor/normal activity ratio was 2.37. Among prognostic factors, the nuclear grade, evaluated according to Schnitt et al., was found to be correlated with the activity ratio. Our results suggest a role for phospholipase D in human breast tumors. An elevation in phospholipase D activity is useful as a potential marker for malignant disease in the breast.

[Mid-term results in coronary revascularization using the right gastroepiploic artery graft]

We studied the mid-term results in 191 patients (including emergent operation in 27 patients) who have performed coronary artery bypass grafting (CABG) using the right gastroepiploic artery (REGA) for 74 months (mean follow up period was 37 months). We evaluated the postoperative results in terms of 1. mortality and survival rate, 2. graft angiography, 3. cardiac event free rate and 4. abdominal complications. We had operative death in 6 patients (3.1%) including 3 patients of emergent operations. Late deaths were found in 11 patients (5.9%): 2 patients were cardiac death and 9 were non-cardiac. The actual survival rates were 94.2% at one year, 90.0% at three years and 85.9% at five years. Early patency rate of the RGEA was 98.9% (n = 178). However flow competition between the RGEA and native coronary artery was seen in 42 patients (24.0%). Mid-term patency rate was 96.4% (n = 28). According to mid-term graft angiography, 1 patient improved and 5 patients got worse in comparison with early control. Cardiac event free rates were 98.2% at 1 year, 94.8% at 3 years and 92.7% at 5 years. Abdominal complications were observed in 5 patients (1 patient of bleeding from the RGEA, 1 of gastric perforation, 2 of bleeding from gastric ulcer and 1 of pyloric stenosis) at early period and in 7 patients (2 patients of incisional hernia and 5 of gastric cancer) at long-term period. Early and mid-term results of CABG using the RGEA were quite good. However, the RGEA had a tendency of flow competition against native coronary artery and a problem of gastric cancer after the operation.

Induction of cyclobutane pyrimidine dimer photolyase in cultured fish cells by UVA and blue light

The cyclobutane pyrimidine dimer (CPD) photolyase in fish cells is known to be regulated by environmental factors, such as light, hydrogen peroxide and growth inhibition. The induction of CPD photolyase by light in cultured goldfish cells was dependent on the wavelength of the light, and UVA and blue light had high inductive activity. The spectrum for CPD photolyase activity was different from that for the induction. Treatment with blue or yellow light for a short time, which did not induce any CPD photolyase, induced high CPD photolyase activity in the presence of the photosensitizers, TPPS (monosulfonated meso-tetraphenyl porphine) and ALPS (aluminum phthalocyanine tetrasulfonate), respectively. These results suggest that the induction of CPD photolyase might be triggered by active oxygen produced by light and cellular photosensitizers. We also found that immediately after treatment with UVA, blue light or a photosensitizer in combination with light, cellular attachment to the substratum was enhanced, as was the CPD photolyase activity. Pretreatment with a flavonoid, quercetin, inhibited both photoinduction of CPD photolyase and enhancement of cellular attachment. Vitamin E inhibited only photoinduction of CPD photolyase activity. Treatment with H7, a strong inhibitor for protein kinase C, after light treatment inhibited photoinduction of CPD photolyase activity, but an analogue of H7, Ha1004, which is a weak inhibitor of protein kinase C, did not have such an effect.

PCR analysis of Lewis-negative gene mutations and the distribution of Lewis alleles in a Japanese population

Three mutations in the Lewis-negative gene, T59G, G508A and T1067A, have been detected by means of a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 149 unrelated Japanese individuals. We found three common Lewis alleles-Le (without the T59G, G508A, and T1067A mutations), le1 (with the T59G and G508A mutations), and le2 (with the T59G and T1067A mutations) in a Japanese population. In addition, we also found one rare Lewis-negative allele, le3 (only with the T1067A mutation). The allele frequencies of Le, le1, le2, and le3 were 0.607, 0.275, 0.114, and 0.003, respectively. Our results were in accordance with those expected by the Hardy-Weinberg equilibrium. Some statistical parameters of forensic interest were also calculated.

Flow competition of the right gastroepiploic artery graft in coronary revascularization

BACKGROUND

In recent years, there has been a substantial increase in the use of arterial grafts for coronary revascularization. Arterial grafts are more vulnerable than saphenous vein grafts to hypoperfusion syndrome. The purpose of this study was to examine flow competition between the right gastroepiploic artery and native coronary arteries in patients undergoing coronary artery bypass grafting.

METHODS

Between December 1989 and July 1995, 182 patients underwent coronary artery bypass grafting using the right gastroepiploic artery. Coronary flow patterns were examined in 172 patients by postoperative angiography. Flow patterns were divided into four types: right gastroepiploic artery dependent (n = 128), balanced (n = 24), native dependent (n = 18), or occluded (n = 2).

RESULTS

All grafts with an old myocardial infarction (n = 75) and 94% of grafts with 99% stenosis (n = 16) were classified in the right gastroepiploic artery-dependent category. In patients with angina pectoris, flow patterns were more frequently classified as right gastroepiploic artery dependent, with increasingly severe native coronary artery proximal stenoses (99% > 90% > 75%) or with stenoses more distal in location.

CONCLUSIONS

Flow competition depended on three factors: the viability of the revascularized area, the degree of proximal stenosis, and the location of stenosis. Right gastroepiploic artery grafts should be selected for coronary artery bypass grafting with consideration of these three factors.

[A quantitative study of regional cerebral blood flow in childhood using 123I-IMP-SPECT: with emphasis on age-related changes]

Single photon emission computed tomography (SPECT), using N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) was used for quantitative analysis of regional cerebral blood flow (rCBF) on 26 individuals between 0 and 19 years of age. The rCBF showed age-related changes; it was low in early infancy, increased in late infancy through early childhood, and decreased and remained constant after puberty. The rCBF through cerebral cortex varied more greatly than through thalamus and cerebellum, and seemed to depend more closely on age. In the case of 4 months of age rCBF was very low at the frontal region and was very high at the occipital region. In more older cases, rCBF in the cerebral cortex was higher than in the thalamus. In childhood, rCBF was very inconsistent and showed a great inter-individual variance.