A Y-associated allele is shared among a few ethnic groups of Asia

In our previous study, both of Y-associated alleles, Y1 and Y2, were detected in Japanese and Koreans, but only the Y1 allele was detected in each of other populations including Chinese in both Beijin and Guangzhou areas, Caucasians, Africans, and Jewish. In the present study, these observations were extended to other ethnic groups in East Asia. Evenks in central Siberia and Khalkhs in Mongolia had only the Y1 allele. On the other hand, two ethnic groups, Fo-lo and Hakka, in Taiwan had both of the Y1 and the Y2 alleles. Three of the eight Y2-positive men, 2 Fo-lo and a Hakka, shared family name Chen. Both Hakka people and ancestors of Chen families could be traced to the Province of Henan in northern China in early 4th century. They arrived in Fujian/Guangdong area in the south-east China via various routes and then some of them migrated to Taiwan in the 18th century. It is tempting to speculate that the Y2 allele may be originated from an ancestral population in Henan from which, Japanese, Koreans, and some of the Taiwanese diverged.

Trace analysis of acetaldehyde as fluorogenic derivative by high performance liquid chromatography

A sensitive method is described for the determination of acetaldehyde as a fluorogenic derivative of decahydroacridin-1,8-dione by high performance liquid chromatography. The analytical derivatization is based on the reaction of acetaldehyde in an acidic aqueous system with 1,3-cyclohexanedione and ammonium acetate. The resulting derivative was separated by a reversed-phase C-18 column and monitored with a fluorescent detector (lambda ex, 375nm; lambda em, 512nm). Several parameters affecting the derivatization of acetaldehyde were studied. The linear range of the method for the quantitation of acetaldehyde was between 20 and 800 pmol in aqueous sample (0.5 mL). Application of the method to the analysis of acetaldehyde in plasma was performed.

Bilateral internal carotid artery aneurysms with diffuse intracranial calcification: report of one case

A 15-year-old girl with voice hoarseness and neck soreness for 4 months had a pulsating mass, sized 3 x 5 cm, adjacent to the right mastoid process. Physical examination revealed normal blood pressure recordings in 4 limbs and no stigmata of Marfan syndrome. Examination of the oral cavity showed bulging of the right pharyngeal wall medially, and the tongue deviated to the right at protrusion. Laboratory workups including complete blood counts, biochemistry, electrolytes, serological and immunological surveys revealed nothing particular. Echocardiography disclosed mild aortic dilatation. Computed tomography of the head and neck revealed bilateral carotid aneurysms with extensive intracranial calcification. The saccular aneurysm over the left internal carotid artery was resected, and end-to-end anastomosis of the left internal carotid artery was performed. The giant occluded right carotid aneurysm was left unmanaged. The combination of bilateral carotid aneurysms and intracranial calcification has not been reported. The etiologies are discussed and a causal relationship between these two conditions is postulated.

Kabuki make-up syndrome associated with congenital heart disease

The Kabuki make-up syndrome, reported in 1981 by Niikawa et al. and Kuroki et al. independently, is also known as "Niikawa-Kuroki syndrome". Here we report two cases of this syndrome, both of them were boys, showing facial dysmorphism, hand abnormalities and congenital heart disease. The first case had developmental retardation noticed since 3 months old and frequent upper respiratory tract infections in the following years, and the cardiac echo revealed mitral regurgitation and tricuspid regurgitation. The second case had patent ductus arteriosus and ventricular septal defect diagnosed at 17 days old. He underwent corrective surgery for his heart problems, he also couldn't complete a sentence at two and half years old. It was estimated that the incidence of this syndrome was 1/32,000 in Japanese Children, and Chinese are similar to Japanese as yellow-skinned oriental, there should be more cases in our country, and a detailed cardiac study may be necessary for them.

Pretibial epidermolysis bullosa: a clinicopathologic study

BACKGROUND

Pretibial epidermolysis bullosa (PEB) is a rare variant of dystrophic epidermolysis bullosa (DEB) that predominantly involves the pretibial skin.

OBJECTIVE

We report 19 cases of DEB with pretibial predilection and our findings on anchoring fibrils.

METHODS

Patients with blisters and scars that primarily involved the pretibial were selected. Blisters and noninvolved skin were studied by light and electron microscopy. Anchoring fibrils were quantified by morphometry.

RESULTS

There were 19 patients from 13 families. The inheritance was autosomal dominant in 10 families and sporadic in one family, and sibling involvement was present in two families. Nail dystrophy was noted in all patients. Pruritus was a common feature. Extensive prurigo occurred in four patients. Eight patients had skin lesions that exclusively affected the legs and were diagnosed as PEB. The remaining patients also showed some albopapuloid or hypertrophic scars at sites other than the leg, features seen in the albopapuloid or Cockayne-Touraine types. These were labeled as albopapuloid PEB or Cockayne-Touraine PEB. Common ancestry and various combinations of PEB, with albopapuloid or Cockayne-Touraine type of EB, were noted in some families. Compared with normal controls, the anchoring fibrils were rudimentary and sparser in both lesional and nonpredilected normal skin, although in the latter the changes were less marked in PEB than in the albopapuloid or Cockayne-Touraine types.

CONCLUSION

Common ancestry may contribute to the higher incidence of DEB, especially PEB, in Tainan, Taiwan. The abnormalities of anchoring fibrils were not restricted to the predilected site in PEB and did not distinguish PEB from other types of DEB.

X chromosome mosaicism in patients with recurrent abortion or premature ovarian failure

X chromosome mosaicism is usually associated with abnormal sexual development and reproductive performance, such as recurrent spontaneous abortion, primary or secondary amenorrhea, infertility, and premature ovarian failure. However, there is a paucity of literature which discusses these relationships. From July 1988 to December 1992, a total of 105 couples with a history of recurrent spontaneous abortion from a genetic counseling clinic and 61 women with a history of premature ovarian failure followed up in reproductive endocrinology clinics were assembled, and chromosomal analysis of peripheral blood lymphocytes was carried out. X chromosome mosaicism was found in six individuals (2.9%) out of the 105 couples with recurrent spontaneous abortion, and in five (8.2%) out of 61 women with premature ovarian failure. The karyotypes were 45,X/46,XX/47,XXX in five cases, 45,X/46,X in four cases, and 46,XX/47,XXX in two cases. The cases of complex X chromosome mosaicism (45,X/46,XX/47,XXX) presented recurrent spontaneous abortion in four cases and premature ovarian failure in one case. The cases of mosaic Turner's syndrome (45,X/46,XX) presented premature ovarian failure in three cases and recurrent spontaneous abortion in one case. The two cases of mosaic triple-X syndrome (46,XX/47,XXX) presented with premature ovarian failure and recurrent spontaneous abortion, respectively. However, the ratio of mosaic cell lines does not correlate well with the phenotypic manifestations in our cases. Our preliminary data suggest that chromosomal analysis should be done routinely in every couple with recurrent spontaneous abortion and in women with premature ovarian failure. The reproductive performance of X chromosome mosaicism is highly variable and difficult to define.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased aortic endothelial death and enhanced transendothelial macromolecular transport in streptozotocin-diabetic rats

Hypertension, cigarette smoking and diabetes mellitus are well-known risk factors for atherosclerosis and coronary heart disease. Repeated endothelial cell injury and increased lipid entry have been suggested as initiating events in atherogenesis. Our previous studies have demonstrated that the frequency of endothelial cell death and associated endothelial permeability were significantly increased in the aorta of spontaneously hypertensive rats and chronic oral nicotine-treated rats. In the present investigation, we examined the hypothesis that diabetes also increases the frequency of arterial endothelial cell death and hence transendothelial macromolecular transport, which may have some implications in increasing lipid entry and thus accelerating atherogenesis. Diabetes was induced in 15 male Sprague-Dawley rats by intraperitoneal injection of 60 mg streptozotocin per kg body weight. The duration of diabetes was 6 weeks. A group of 15 age-matched rats, injected only with the buffer and maintained over the same time period, served as the controls. In en face preparations of the thoracic aorta, IgG-containing dead endothelial cells were identified by an indirect immunoperoxidase method, and endothelial leakage to Evans blue-albumin complexes was quantified by fluorescence microscopy. Diabetic rats, compared to control rats, had significantly higher values for the frequency of endothelial cell death (0.77 +/- 0.10% vs 0.38 +/- 0.04%; p < 0.005 by two-tailed, unpaired Student's t-test) and the number density of Evans blue-albumin leaky foci (4.33 +/- 0.48/mm2 vs 2.99 +/- 0.38/mm2; p < 0.05 by two-tailed, unpaired t-test) in the aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

[Insulinoma in childhood--report of a case]

A 14-year-old boy was having recurrent hypoglycemia over the past 6 months, so he was brought to our hospital for further evaluation. During the episodes of hypoglycemia, his serum insulin level was inappropriately high and the symptoms of hypoglycemia were dramatically ameliorated by intravenously administering glucose bolus. Computed tomography of the abdomen revealed a 1 x 1 cm mass located at the tail of the pancreas. Under the impression of an insulinoma, enucleation of the tumor was performed smoothly, and the pathological finding confirmed the diagnosis. The postoperative course was smooth and no episodes of hypoglycemia were noted after treatment. In children with hypoglycemic attacks, adequate blood sampling before correction to determine plasma insulin levels is essential.

Rigid spine syndrome presenting with respiratory failure--report of one case

A case of rigid spine syndrome presenting with respiratory failure was reported. A seven-year-old girl had had dyspnea and orthopnea for one month. Symptoms had aggravated gradually and she was in a state of respiratory failure on arrival at our hospital. There was no evidence of active lung lesions and response to mechanical ventilation was good. Physical examination revealed an extremely thin girl with marked flexion limitation of neck and severe wasting of sternocleidomastoid and intercostal muscles. Serum creatine phosphokinase was moderately elevated (801 IU/L). Muscle biopsy specimen obtained from the right quadriceps femoris revealed increased perimyseal connective tissue and marked Type II fiber atrophy. Electromyography of left paraspinal muscles demonstrated small amplitude, short duration motor unit potentials. She received tracheostomy and a home-care ventilator use during sleep. Ventilatory insufficiency, though rare, should be anticipated in patients with rigid spine syndrome, and timely ventilatory support should be given.

Inhibitory effects of curcumin on protein kinase C activity induced by 12-O-tetradecanoyl-phorbol-13-acetate in NIH 3T3 cells

Curcumin is a dietary pigment responsible for the yellow color of curry. It is a potent inhibitor of tumor promotion induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in mouse skin. When mouse fibroblast cells (NIH 3T3) were treated with TPA alone, protein kinase C (PKC) translocated from the cytosolic fraction to the particulate fraction. Treatment with 15 or 20 microns curcumin for 15 min inhibited TPA-induced PKC activity in particulate fraction by 26 or 60% and did not affect the level of PKC protein. Curcumin also inhibited PKC activity in both cytosolic and particulate fractions in vitro by competing with phosphatidylserine. However, the inhibitory effect of curcumin was reduced after preincubation with the thiol compounds. These findings suggest that the suppression of PKC activity may contribute to the molecular mechanism of inhibition of TPA-induced tumor promotion by curcumin.

Effect of pravastatin on fatty acid profile of low density lipoprotein in patients with hypercholesterolemia

We gave pravastatin, an HMG-CoA reductase inhibitor, to 21 hypercholesterolemic patients for 12 weeks after they had been on dietary therapy for 12 weeks. In addition to inducing a significant reduction of total cholesterol and LDL-cholesterol, pravastatin significantly decreased the proportion of linoleic acid (18:2) and increased that of saturated (FA) (16:0 and 18:0) in the cholesterol ester of LDL. Linoleic acid was also reduced in the triglyceride of LDL. Besides, monounsaturated FA (16:1 and 18:1) were increased in the cholesterol ester, triglyceride and phospholipid of LDL, but the changes in monounsaturated FA were not statistically significant. The effect of pravastatin on the FA profile of LDL was similar to that of fibric acid derivatives. The mechanism as well as the clinical implication of these changes await further investigation.

Successful management of a pregnancy with maternal phenylketonuria: report of a case

Maternal phenylketonuria (PKU) is associated with significant complications such as mental retardation, microcephaly and congenital heart defects in nonphenylketonuric offspring. Dietary control with a low phenylalanine diet during the gestation period is effective in improving perinatal outcome in these cases. We present the case of a 27-year-old woman with classical features of PKU who had previously given birth to three babies, all of whom died of congenital heart disease. A low phenylalanine diet was started one month prior to the pregnancy and satisfactory fetal outcome was achieved.

X-linked recessive inheritance of dysgenesis of corpus callosum in a Chinese family

This report describes a new syndrome of dysgenesis of corpus callosum with other anomalies, presenting as microcephaly, mental retardation, spasticity, and unusual facial appearance in 2 Chinese brothers and their maternal cousins. To date, there has not been any case reported in the Chinese population of this syndrome. All 4 patients in this report present with the same unusual face. Hydrocephalus and/or interhemispheric cyst were found among them. This syndrome is transmitted as an X-linked trait. The nosology is reviewed and discussed.

Long-term nicotine exposure increases aortic endothelial cell death and enhances transendothelial macromolecular transport in rats

Repeated endothelial cell injury has been suggested as an initiating factor in atherogenesis. Dying or dead endothelial cells have been shown to make significant contributions to the local enhancement of transendothelial macromolecular transport. Since cigarette smoking is one of the major risk factors for atherosclerosis, we examined the hypothesis that smoking accelerates atherogenesis by increasing the frequency of endothelial cell death and hence transendothelial macromolecular transport. Sixteen male Sprague-Dawley rats were given nicotine at a weight-adjusted dose of 5 mg/kg body wt per day in their drinking water over a period of 6 weeks. A group of 16 age-matched male Sprague-Dawley rats not exposed to nicotine and maintained over the same time period served as the control group. In en face preparations of thoracic aorta, immunoglobulin G-containing dying or dead endothelial cells were identified by the indirect immunoperoxidase method, and endothelial leakage to Evans blue-albumin (EBA) complexes (5 minutes after intravenous injection) was visualized by fluorescence microscopy. The results showed that in nicotine-treated rats, 51% of dead endothelial cells were associated with EBA leakage, which was responsible for 57% of total EBA leaky foci. Both the frequency of endothelial cell death (0.94 +/- 0.11% versus 0.40 +/- 0.04%, p < 0.0001 by two-tailed, unpaired Student's t test) and the number density of EBA leaky foci (6.45 +/- 1.23/mm2 versus 3.30 +/- 0.49/mm2, p < 0.05 by two-tailed, unpaired t test) were significantly greater in nicotine-treated rats than in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

[Anthropometric study on Down syndrome in Taiwan]

Anthropometric studies of Down syndrome in foreign children had been reported. To have similar information for Chinese children with Down syndrome, data based on 1624 measurements of height and 1208 measurements of weight were done on 496 children who took part in a collaborative study done via several hospitals and institutions in Taiwan. Height and weight were measured using standard methods. Additional data about these children were also solicited from hospital and school records to obtain semilongitudinal data which were then analyzed with SAS PC software. Descriptive statistics and percentiles were estimated using flexible mathematical functions. Results showed that ethnic Chinese children with Down syndrome were significantly shorter than normal children. Mean weight, however, was not significantly different from normal children. Centile charts for assessment of stature and weight are also presented.

Cytogenetic study of twenty-two intracranial tumors

G-banded chromosomal analysis was performed on primary cultures of 22 intracranial tumors, including eight astrocytomas, nine meningiomas, two dermoid cysts, one acoustic neuroma, one pineal teratoma and one eosinophilic granuloma. One or more chromosomally abnormal clones were observed in 6 (75%) gliomas and 5 (56%) meningiomas. There was no chromosomal abnormality found in one of the dermoid cysts, the acoustic neuroma or the eosinophilic granuloma. A teratoma and a grade IV glioma had heterogeneous hyperdiploid karyotypes. Furthermore, astrocytomas displayed nonrandom loss of chromosomes #19, #21, #22 and Y. In meningiomas, characteristic changes involving chromosome 22 were found in 5 tumors. One meningioma had a ring chromosome in addition to chromosomal loss. With our culture and harvesting techniques, cytogenetic studies can be successfully performed on nearly all intracranial tumor explants, including those derived from small biopsy specimens. Also, in our study, specific nonrandom chromosomal anomalies were found.

An enkephalin analog stimulates growth of tilapia

A synthetic enkephalin analog (Tyr-D-Trp-Ala-D-Phe-NH2) was administered to juvenile hybrid tilapia (Tilapia nilotica ×T. aurea) by immersing the fish for 15 minutes per week into one of two doses of the hormone for 8 weeks. Growth, food conversion efficiency, body weight, specific growth rate, food conversion efficiency and feed consumption were all significantly increased as a result of enkephalin treatment. The low dose (10µg/100 ml water) of enkephalin analog had a better stimulation effect than that of the high dose (100µg/100 ml water). Liver protein and protein/DNA ratio were higher in both treatment groups than in the control group. Tissue-body indices and muscle proximate composition were similar in the treatment and control groups. The growth stimulation in fish treated with the enkephalin analog was possibly mediated by an increase in growth hormone secretion.

Unusual cardiac malformations in Holt-Oram syndrome: report of two cases

The Holt-Oram syndrome is a hereditary disease which associated with upper limbs anomalies and cardiac defects such as secundum type atrial septal defect. Two cases of this syndrome with unusual cardiac findings are reported: One has an unroofing coronary sinus type atrial septal defect and preexcitation syndrome, the other has pentalogy of Fallot.

Serratia marcescens bacteremia

Serratia marcescens bacteremia has become ubiquitous recently. S. marcescens bacteremia, either hospital- or community-acquired, can no longer be treated as insignificant. We reviewed 23 episodes of S. marcescens bacteremia in 1985. Among them, 17 patients (74%) were hospital-acquired infections, while 6 (26%) were community-acquired. Nine patients died, and the case fatality rate was 39%. Eleven patients (48%) had no clinically apparent source of infection, 5 (22%) had urinary tract infection, 3 (13%) had pneumonia, 2 (9%) had biliary tract infection, 1 (4%) had intra-abdominal infection, and 1 (4%) had skin and soft-tissue infection. Nosocomial isolates are often resistant to many antibiotics. Amikacin and the beta-lactamase-stable (third generation) cephalosporins are superior to gentamicin in the treatment of nosocomial S. marcescens bacteremia. We here emphasize that the awareness and treatment of S. marcescens bacteremia in daily clinical practice is unequivocally critical.

Temporal and spatial changes in macromolecular uptake in rat thoracic aorta and relation to [3H]thymidine uptake

Leaky endothelial junctions associated with cell turnover have been suggested to be a hydrophilic pathway for the transport of macromolecules across the vascular endothelium. To demonstrate focal increases in endothelial permeability, the occurrence of localized uptake of macromolecules in the rat thoracic aorta was studied at various time periods after intravascular administration of Evans blue-albumin (EBA) complexes. With fluorescence microscopy, EBA uptake in the rat thoracic aorta was visible either as discrete spots or as larger areas in both en face and cross-sectional preparations. The average size of EBA leaky spots increased with dye circulation time, indicating that there is a continuous influx of macromolecules through the transiently leaky junctions in these foci with subsequent diffusion in the vessel wall. There was heterogeneity in EBA spot size distribution, suggesting that endothelial cells undergoing turnover in different phases of the cell cycle might exhibit different extents of junctional leakage to macromolecules. The technique of [3H]thymidine labeling autoradiography was applied to en face preparations of the rat thoracic aorta for identifying replicating endothelial cells. The correlation of EBA leakage with [3H]thymidine-labeled endothelial cells was determined. Only 26% of endothelial cells with nuclear incorporation of [3H]thymidine were shown to be associated with EBA leaky foci. This lack of correlation suggests that alterations in endothelial junctional permeability accompanying cell turnover might occur only in some limited time periods of the cell cycle, e.g., the mitotic (M) phase, rather than the whole period of [3H]thymidine labeling.

Role of dying endothelial cells in transendothelial macromolecular transport

There are focal areas in the aorta with an enhanced endothelial permeability to macromolecules, as indicated by the focal uptake of the protein-binding azo dye Evans blue in vivo. These areas exhibit high rates of endothelial cell turnover and a number of structural characteristics in en face endothelial morphology. To determine the relationship of endothelial cell death to macromolecular leakage at the level of individual endothelial cells, thoracic aortas of 12 adult male Sprague-Dawley rats were studied at 3 to 5 minutes after intravenous administration of Evans blue-albumin (EBA). Leakage of EBA around individual endothelial cells in en face preparations of the aorta was visualized by fluorescence microscopy. Dying or dead endothelial cells were identified by indirect immunoglobulin G (IgG) immunocytochemistry. Although endothelial cell death is uncommon in normal aortic endothedium (i.e., an average frequency of 0.48%), a high percentage (63%) of IgG-containing dying or dead endothelial cells was found to be associated with EBA leakage. These dying or dead endothelial cells were responsible for 37% of total EBA leaky foci. The results suggest that, in addition to mitotic endothelial cells, the dying or dead endothelial cells also make significant contributions to the local enhancement in aortic endothelial permeability. The present findings lend further support to the "cell turnover-leaky junction" hypothesis for the localization of atherosclerosis.

Reliability of a clinical kinematic assessment of the sit-to-stand movement

We examined the reproducibility of a kinematic assessment of the sit-to-stand movement in 15 healthy subjects using a standardized protocol. We examined the within-rater and between-rater reliability of the assessment using a clinically feasible method, the video-goniometric measurement method, to analyze the task. Two variables were measured to characterize the sit-to-stand movement: 1) joint angles for four body segments (head, trunk, knee, and ankle) and 2) three events (maximal trunk flexion, lift-off, and maximal trunk extension). High reproducibility was found for all joint angles, except for the head angle. Both within-rater and between-rater goniometric measurements were highly reliable (ICC greater than .80). Identification of the events was reproducible within raters and between different raters. We conclude that this method can lead to reliable assessments of a healthy population. The reliability data established in this study can be used to help clinicians determine the impairments of patients.

Transendothelial macromolecular transport in the aorta of spontaneously hypertensive rats

Leaky endothelial junctions occurring during cell turnover have been postulated to be a major pathway for enhanced lipoprotein transport across the vascular endothelial layer, which leads to the development of atherosclerosis. Because hypertension has been well documented as one of the major risk factors for atherosclerosis, we explored the possibility that hypertension accelerates atherogenesis by increasing the turnover of endothelial cells and hence the transendothelial macromolecular permeability. The investigations were performed on thoracic aortas of 10 male 3-4-month-old spontaneously hypertensive rats and eight male age-matched Wistar-Kyoto normotensive rats. In en face preparations of aortic specimens, mitotic endothelial cells were identified by hematoxylin nuclear staining; dying or dead endothelial cells containing cytoplasmic immunoglobulin G were detected by indirect immunoperoxidase technique; and endothelial leakage to Evans blue-albumin conjugate was visualized by fluorescence microscopy. The number of leaky foci per unit endothelial surface area in spontaneously hypertensive rats was found to be approximately three times that in Wistar-Kyoto control rats; the frequencies of both endothelial cell mitosis and death in spontaneously hypertensive rats were also approximately three times the corresponding values in Wistar-Kyoto rats. These findings indicate that hypertension in spontaneously hypertensive rats is accompanied by increased endothelial cell turnover and an attendant enhancement of permeability to macromolecules.

[Studies on antigens of human lung adenocarcinoma with McAb LC-1]

The soluble antigens extracted from both human lung adenocarcinoma cell line SPC-A-1, and normal adult lung tissue with non-idet P-40 were subjected to 10% SDS-PAGE. The number of bands distinguishable by naked eyes of lung adenocarcinoma are 57, in which 4 bands are more significant. The bands of normal human lung tissue are 52, in which 2 bands are more significant. The molecular weights of these bands mainly are within 30 to 94 KD The thin layer chromatographs of these two antigenic extracts have shown that there is difference in their sugar content, but both of them shown little sialic acid. The Immunoblot pattern of McAb LC-1 reacted with the extracts of SPC-A-1 cells shows that all of 3 bands detected can be stained by alcian blue, indicating that they are glycoproteins. However, of them two bands, M. W. of 70 KD and 51 KD can also be stained by Sudan Black B, indicating that these two bands are glycolipoproteins. The ganglioside and neutral glycolipid can inhibit the binding of LC-1 with the extract of SPC-A-1 cells. The results indicate that the epitopes of SPC-A-1 cell extract reacted with McAb LC-1 are probably located in the polysaccharide.

Macromolecular transport across arterial and venous endothelium in rats. Studies with Evans blue-albumin and horseradish peroxidase

Atherosclerotic lesions are characterized by lipid infiltration in regions with high rates of endothelial cell turnover. The present investigation was designed to elucidate the route of macromolecular transport across vascular endothelium. The aorta and vena cava of male Sprague-Dawley rats were perfusion-fixed after the intravenous injection of Evans-blue albumin (EBA) or horseradish peroxidase (HRP). Fluorescence microscopic examination of en face preparation of the aorta stained with hematoxylin allowed the identification of endothelial cells that underwent mitosis, together with the localization and quantification of fluorescent spots for EBA leakage. The HRP specimens were subjected to histochemical treatment, and HRP leakage was seen as brown spots under the light microscope. Silver nitrate stain was added in both EBA and HRP studies to outline cell boundaries and to visualize stigmata, stomata, and dead cells. In the aorta, almost every dividing cell showed junctional leakage to albumin and HRP, with clustering of leaky spots around the branch orifices. Time-dependent studies showed gradual increases in the diameter and number of these heterogeneously sized leaky spots, which finally fused to sizes corresponding to the "blue areas" for EBA or "brown areas" for HRP. Compared with arteries, veins had fewer mitotic cells, but more dead cells and diffuse dye-staining areas, indicating a more rapid transport of macromolecules. The leaky spots in the artery were associated mainly with mitotic cells, dead cells, and stigmata, whereas those in the vein occurred primarily at regions with dead cells. These results suggest that the preferential association of the enhanced transport of macromolecules with mitosis in the arterial as compared to venous endothelium and the differential behavior in transmural transport between arteries and veins may form the basis for the predilection of atherosclerosis in arteries.