Suppressive effect of perinatal testes on the differentiation of fetal ovaries transplanted into adult males in the rat

A 14 d ovarian primordium was transplanted with a fetal testis (13-18 d and 21 d of gestation) or a neonatal testis (15, 20, 30 and 45 d after birth) into the renal subcapsular position of an adult male rat. Two weeks after transplantation, transplants were examined as to the degree of ovarian and testicular differentiation. In the combination of a 14 d ovary and a 13 d testis, there were 3 types of result: either the ovary or the testis alone developed or both gonads developed well. Ovaries transplanted in union with 15-18 d testes did not develop, although the testes developed normally. Some ovaries in union with 21 d testes developed normally. In combination with infantile testes, the incidence of developed ovaries increased as the age of testes advanced. These results suggest that the 13 d fetal testes begin to suppress the development of cotransplanted 14 d ovaries, that 14-18 d fetal testes maintain such suppressive effects and that this effect gradually diminishes in infantile testes as they progress toward 45 d after birth.

Application of long-circulating liposomes to cancer photodynamic therapy

Photodynamic therapy (PDT) as a cancer treatment is notable for its quite low side effects in comparison with those of chemotherapy and radiotherapy. However, the accumulation of porphyrin derivatives used in PDT into tumor tissues is rather low. Since long-circulating liposomes are known to accumulate passively into tumor tissues, we liposomalized a porphyrin derivative, benzoporphyrin derivative monoacid ring A (BPD-MA), and used these liposomes to investigate the usefulness of PDT for tumor-bearing mice. BPD-MA was liposomalized into glucuronate-modified liposomes, which are known to be long-circulating. These liposomes were injected i.v. into Balb/c mice bearing Meth A sarcoma, and tumor regression and survival time were monitored after irradiation with laser light. Tumor regression and complete curing of tumor (80% cure rate by the treatment with 6 mg/kg BPD-MA) were observed when long circulating liposomalized BPD-MA was injected and laser-irradiated. In contrast, only a 20% cure rate was obtained when the animals were treated with BPD-MA solution or BPD-MA entrapped in conventional liposomes. These results suggest that a long-circulating liposomal formulation of photo-sensitive agents is useful for PDT.

Reconstruction of posttraumatic defects of the foot by flow-through anterolateral or anteromedial thigh flaps with preservation of posterior tibial vessels

Massive posttraumatic defects of the foot in 4 patients and a tibial malunion in another were repaired by flow-through anterior (anterolateral and anteromedial) thigh flaps. Posterior tibial vessels were used as the recipient vessel just below the level of the medial malleolus. Soft-tissue defects in foot-injured patients were covered with flow-through anterior thigh flaps interposing the descending branch of the lateral circumflex femoral system between the transected posterior tibial vessels. In another patient, a combined anteromedial thigh flap and vascularized iliac bone cross-leg "chimeric" flap were successfully transferred for the reconstruction of a malunion of a tibial fracture, which had been accompanied by severe vascular damage to the thigh. The utilization of derivative branches from the lateral circumflex femoral system facilitates revascularization of ischemic areas and simultaneous transplantation of multiple components, as well as preserves recipient vessels. Owing to the stable blood supply, these flaps can be readily processed into both deepithelialized and thin flaps.

Topographic measurements of precision-ground optical glasses

We studied the surfaces of six precision-ground optical glass samples of fused silica, BK-7, BaCD16, LaC14, NbF1, and LHG8 glass, using a mechanical profiler, a photon tunneling microscope, and a scanning force microscope. The measured roughnesses of the scanning force microscope varied from 3.5 A rms for BK-7 glass to 30 A rms for LHG8 laser glass. Good agreement was obtained among the roughness values measured with all three instruments.

The effects of chronic administration of nimodipine on age-related changes in nitric oxide and its synthase in senescence-accelerated mouse brain

The levels of nitric oxide (NO) and NO synthase (NOS) activities in the brain of young-adult (3 months old), aged (11 months old) and nimodipine-administered (11 months old) senescence-accelerated mouse (SAM), of which SAMP8 sub-strain is inferior in acquisition of learning and has a lower content in testosterone, were compared. Nimodipine, which is L-type calcium ion channel blocker and has memory-enhancing effects, was administered orally for 5 months. In the cerebral cortex of aged SAMP8, NOS activity was increased compared with that of young-adult SAMP8. Though nimodipine did not alter the contents of NO in any brain regions compared with those in aged SAMP8, nimodipine increased NOS activity in the aged cerebellum. Our data suggest that nimodipine may increase NOS activity through elevation of testosterone level, as testosterone increases NOS only in the cerebellum, although further work is clearly needed to ascertain effects of nimodipine on testosterone metabolism and maintenance in the acquisition of learning.

[Clinical studies on acute scrotum--focusing on torsion of the spermatic cord]

Surgical exploration was done on 50 patients with acute scrotum between June 1982 and October 1995. Of them, 24 (48%) had torsion of the spermatic cord, 9 (18%) had torsion of the appendage testis, 11 (22%) had intrascrotal hematoma, 4 (8%) had acute epididymitis, and 2 (4%) had bleeding of testicular tumor. The patients who had torsion of the spermatic cord were between 0 and 26 years of age (the mean: 14.6); 9 had torsion on the right side, and 15 on the left side. Infectious manifestations occurred in about 30%, and Prehn's sign developed in 37.5%. Of all cases, orchiopexy was performed in 10 cases and orchiectomy in 14. The testis was saved in 8 (88.9%) of the 9 patients who underwent surgery within 12 hours after onset. On the contrary, the testis was saved in only 2 (13.3%) of the 15 patients who underwent surgery more than 12 hours after onset. We concluded that early consultation, and exploration by a urologist are obligatory in the treatment of torsion of the spermatic cord.

Relationship between structure and inhibitory effect of arginine analogues on neuronal nitric oxide synthase activity

Since nitric oxide (NO) is synthesized by nitric oxide synthase (NOS) from L-arginine (Arg) which has an amidino group in its molecule, we examined the effect of 29 kinds of Arg analogues on neuronal NOS (nNOS) activity in the rat brain. None of the Arg analogues acted as a substrate for nNOS. Diamidinocystamine, hirudonine, and guanethidine inhibited nNOS activity to 67.3%, 64.2% and 74.1%, respectively, but their inhibitory efficiency was lower than NG-monomethyl-L-arginine (to 36.5%) which is a well known NOS inhibitor. Dimethylguanidine and N-benzoylguanidine also significantly inhibited nNOS activity to 88.0% and 90.7%, respectively. Whereas almost all of the NOS inhibitors previously reported were synthesized by substituting the amidino nitrogen of Arg, none of these new inhibitors were substituted at this position. Furthermore, hirudonine, which is a naturally occurring compound, was thought to act as an agonist at polyamine binding site of the N-methyl-D-aspartate type of glutamate receptor complex. It is also interesting that guanethidine, an antihypertensive agent, inhibit nNOS activity. These new drugs are useful for the investigation not only of the chemical nature of nNOS but also of the physiologic function of NO.

Lack of association of very low density lipoprotein receptor gene polymorphism with Caucasian Alzheimer's disease

To determine whether the association of the very low density lipoprotein receptor (VLDL-R) gene with Alzheimer's disease (AD), which has recently been identified in Japanese AD patients, is commonly observed in AD patients of other ethnic backgrounds, we have investigated the allele frequency of the polymorphic CGG repeat in the 5'-UTR of the VLDL-R gene using a data set of 84 Caucasian AD patients with 104 Caucasian controls. Although the allele frequency of the 8-repeat allele was slightly lower, and that of 9-repeat allele was slightly higher, in the Caucasian AD patients than in Caucasian controls, the differences were not statistically significant. Multiple logistic regression analysis using apolipoprotein E4 (APOE4) allele, 5, 8-, or 9-repeat allele of the VLDL-R gene, sex, and age at onset as the predictors revealed that only the APOE4 allele was significantly associated with AD in the data set of the Caucasian AD patients and controls.

In vivo trafficking of long-circulating liposomes in tumour-bearing mice determined by positron emission tomography

Various kinds of long-circulating liposome, such as ganglioside GM1-, polyethyleneglycol- (PEG-), and glucuronide-modified liposomes, have been developed for passive targeting of liposomal drugs to tumours. To evaluate the in vivo behaviour of such long-circulating liposomes, we investigated the liposomal trafficking, especially early trafficking just after injection of liposomes, by a non-invasive method using positron emission tomography (PET). Liposomes composed of dipalmitoylphosphatidylcholine, cholesterol, and modifier, namely, GM1, distearoylphosphatidylethanolamine (DSPE)-PEG or palmityl-D-glucuronide (PGlcUA), were labelled with [2-18F]-2-fluoro-2-deoxy-D-glucose ([2-18F]FDG), and administered to mice bearing Meth A sarcoma after having been sized to 100 nm. A PET scan was started immediately after injection of liposomes and continued for 120 min. PET images and time-activity curves indicated that PEG liposomes and PGlcUA liposomes were efficiently accumulated in tumour tissues time dependently from immediately after injection. In contrast, GM1 liposomes accumulated less in the tumour as was also the case for control liposomes that contained dipalmitoylphosphatidylglycerol (DPPG) instead of a modifier. Long-circulating liposomes including GM1 liposomes, however, remained in the blood circulation and avoided liver trapping compared with control DPPG liposomes. These data suggest that PGlcUA and PEG liposomes start to accumulate in the tumour just after injection, whereas GM1 liposomes may accumulate in the tumour after a longer period of circulation.

[Inverted papilloma of the posterior urethra: a case report]

A case of inverted papilloma of the posterior urethra is reported. A 59-year-old male was admitted with the chief complaint of difficulty in urination. Cystourethroscopy revealed a polypoid tumor with a smooth surface on the stalk arising from the prostatic urethra, concomitant with prostatic hypertrophy. Transurethral resection of the tumor and the prostate was performed. No evidence of recurrence has been noted in the 9 months after surgery. This is the 26 th case of inverted papilloma of the posterior urethra reported in Japan.

Effect of serum protein binding on real-time trafficking of liposomes with different charges analyzed by positron emission tomography

Liposomes have been used as carriers of various materials and as tools for gene transfer: for the latter purpose, positively charged liposomes are usually used. To evaluate the stability in the presence of serum and the in vivo behavior of such liposomes as well as those aspects of neutral and negatively charged liposomes, we investigated liposomal agglutinability in the presence of serum, serum protein binding to these liposomes, and real-time liposomal trafficking by a non-invasive method using positron emission tomography (PET). Liposomes composed of dipalmitoylphosphatidylcholine, cholesterol without or with charged lipid were prepared in the presence of mannitol, and the turbidity change in the presence of serum was determined. Turbidity increase was not observed for so-called long-circulating liposomes, i.e., liposomes modified with glucuronic acid or with poly(ethylene glycol), or for negatively charged liposomes containing dicetyl phosphate (DCP), phosphatidylglycerol, or phosphatidylserine. On the contrary, a significant turbidity increase was observed when positively charged liposomes modified with stearylamine, stearyltrimethylammonium chloride or 1,2-dimyristyloxypropyl-3-dimethylhydroxyethyl bromide (DMRIE), which is known as a component of liposomes for gene transfer, were used. These liposomes were found to have bound a high amount of serum proteins after separation of unbound serum proteins by use of a spin column. The liposomal trafficking in vivo was determined for three kinds of liposomes, i.e., liposomes with DMRIE, those with DCP, and those without charged lipids. These liposomes were prepared in the presence of 2-[18F]fluoro-2-deoxy-D-glucose ([2-18F]FDG), and the [2-18F]FDG-labeled liposomes were administered to mice to perform PET scans. Positively charged liposomes containing DMRIE showed high accumulation in the liver compared with neutral and negatively charged liposomes. Since DMRIE-liposomes tended to aggregate in the presence of serum, and to be associated with serum protein, these characteristics may lead to the high uptake of DMRIE-liposomes by the liver.

Antitumor activity of vincristine encapsulated in glucuronide-modified long-circulating liposomes in mice bearing Meth A sarcoma

Liposomes modified with the uronic acid derivative palmityl-D-glucuronide (PGlcUA) have a long circulation time and tend to accumulate in the tumors of tumor-bearing mice. Taking advantage of this character, we investigated the therapeutic effect of vincristine (VCR) encapsulated in liposomes containing PGlcUA (dipalmitoylphosphatidylcholine/cholesterol/PGlcUA = 4:4:1 as a molar ratio) on tumor-bearing mice. VCR was loaded into liposomes by a remote loading method, and then free or liposomal VCR was injected intravenously into BALB/c mice bearing Meth A sarcoma implanted subcutaneously 5 days before hand. Single-dose administration of VCR (3.0 mg/kg) in PGlcUA-liposomes significantly suppressed tumor growth, and prolonged the survival time (T/C = 1.37). Furthermore, two-dose administration of the liposomes cured one third of the animals. The therapeutic effect of PGlcUA-liposomes was greater than that of control liposomes containing dipalmitoylphosphatidylglycerol instead of PGlcUA. PGlcUA-liposomes might thus be a useful tool for delivering antitumor agents to tumor tissues.

Effect of reducing alveolar surface tension on stress failure in pulmonary capillaries

We previously showed that when pulmonary capillaries are exposed to high transmural pressures, stress failure of the blood-gas barrier occurs. It has been suggested that the surface tension of the alveolar lining layer may protect against stress failure because at high transmural pressures the capillaries bulge into the alveolar spaces. To test this hypothesis, we abolished the gas-liquid surface tension of the alveoli by filling rabbit lungs with normal saline. The lungs were then perfused at capillary transmural pressures of 32.5 or 52.5 cmH2O for 1 min with autologous blood, the blood was washed out with a saline-dextran mixture (3 min), and the lungs were fixed for electron microscopy with buffered glutaraldehyde; all perfusions were done at the same pressure. The frequency of breaks was measured in the capillary endothelial layer, alveolar epithelial layer, and basement membranes, and the data were compared with those in air-filled lungs at the same capillary transmural pressure and lung volume. We found that the frequency of breaks in the endothelium was not significantly different between air and saline filling and that there were fewer breaks in the outer boundary of the epithelial cells. By contrast, after saline filling, a larger number of breaks were seen in the inner boundary of the epithelium. The frequency of disruptions of the inner boundary of the epithelium was closely correlated with the volume of edema fluid collected at the trachea during the perfusion. These breaks in the inner boundary of the epithelium had not previously been seen in air-filled lungs exposed to the same pressures. The results suggest that abolishing the surface tension of the alveolar lining layer removes support from parts of the blood-gas barrier when the capillaries are subjected to a high transmural pressure but that not all portions of the barrier are subjected to the same forces.

Genetic association of the very low density lipoprotein (VLDL) receptor gene with sporadic Alzheimer's disease

A specific isoform of apolipoprotein E has been associated with the accelerated rate of disease expression of sporadic Alzheimer's disease (AD) and late-onset familial AD (FAD). An earlier age at onset has also been demonstrated in familial AD patients with mutations in the amyloid precursor protein (APP) gene (APP717 and APP670/671)13 carrying the APOE epsilon-4 allele compared to those who do not, but not in familial AD patients with APP692 or 693 mutations, or in chromosome 14-linked familial AD patients. Hypothesizing that receptors for apoE-containing lipoproteins act as a potential risk factor for AD, we performed an association study using a polymorphic triplet (CGG) repeat in the gene for the VLDL receptor (VLDL-R), a receptor for apoE-containing lipoproteins. The frequency of the 5-repeat allele was significantly higher in all of the Japanese sporadic AD patients (P < 0.02) than in the Japanese controls. Moreover, the odds ratio was significantly increased in the AD patients homozygous for the 5-repeat allele (OR = 2.1, 95% CI = [1.1-4.2]). Multiple logistic regression analysis reveals that the relative risk conferred by the presence of two copies of the 5-repeat allele and at least one copy of the APOE epsilon-4 allele is 8.7 (95% CI = [2.9-25.8]). Our results suggest that the VLDL-R gene is a susceptibility gene for AD.

Effect of increased duration of high perfusion pressure on stress failure of pulmonary capillaries

We have previously shown that raising the capillary transmural pressure (Ptm) in rabbit lung causes disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers of the wall. In those studies the lungs were perfused with autologous blood (1 min), then saline/dextran (3 min), followed by glutaraldehyde fixative (10 min), all at the same pressure. The present study was designed to determine whether increasing the time of exposure of the capillaries to the increased pressure altered the frequency of stress failure. The procedure was identical to that of the previous study except that the duration of the blood perfusion was extended from 1 to 10 and 100 min. We chose a Ptm of 32.5 cm H2O because our previous studies showed that this caused only a few disruptions per millimeter endothelial and epithelial boundary length (0.7 +/- 0.4 and 0.9 +/- 0.6 (SE), respectively). Ten New Zealand white rabbit lungs were perfused with autologous blood plus homologous blood from additional rabbits for 10 and 100 min. After 100 min of blood perfusion the number of disruptions per millimeter endothelial and epithelial boundary length (0.66 +/- 0.4 and 0.52 +/- 0.33 (SE), respectively) was not significantly different from the earlier study. Thus, increasing the duration of the increased Ptm during blood perfusion by 100-fold did not alter the incidence of stress failure. These results indicated that any viscoelastic behavior resulting in further strain and ultimately failure of the capillary walls is insignificant over a wide range of exposure times to increased pressure under the conditions of this study.

[Short somatosensory evoked potentials in patients with Fukuyama type congenital muscular dystrophy--a comparison with CT and MRI findings]

Seven patients with Fukuyama type congenital muscular dystrophy were studied. Low density areas (LDs) in the cerebral white matter on cranial CT were present in all 4 patients younger than 13 years of age and in 1 of 3 adult patients. LDs corresponded to low signals on T1 weighted MRI image and high signals on T2 weighted MRI image. The follow-up MRI showed a decreased tendency of the abnormal signals in 2 patients. Short somatosensory evoked potentials (SSEPs) in two infants, aged 4 months and 8 months, showed absent or depressed N1 amplitudes and delayed interpeak latencies from P3 to N1. N1 amplitudes increased on follow-up studies. SSEPs of five patients, who were older than 2 years of age, showed normal N1-P3 latencies. Amplitude of N1 was low in 2 patients with LD. Since the absent or depressed amplitude and delayed latency of N1 improved with the decrease of abnormal signals on MRI, we considered that N1 abnormalities show delayed myelination.

Cloning, mapping and expression of PEBP2 alpha C, a third gene encoding the mammalian Runt domain

PEBP2/CBF is a heterodimeric transcription factor composed of alpha and beta subunits. Previously, we reported two distinct mouse genes, PEBP2 alpha A and PEBP2 alpha B, which encode the alpha subunit. PEBP2 alpha B is the homologue of human AML1, encoding the acute myeloid leukemia 1 protein. AML1 and human PEBP2/CBF beta were detected independently at the breakpoints of two characteristic chromosome translocations observed frequently in two subtypes of acute myeloid leukemia. The PEBP2 alpha proteins contain a 128-amino-acid (aa) region highly homologous to the Drosophila melanogaster segmentation gene runt. The evolutionarily conserved region, named the Runt domain, harbors DNA-binding and heterodimerizing activities. In this study, we identified the third Runt-domain-encoding gene, PEBP2 alpha C, which maps to 1p36.11-p36.13 in the human chromosome and encodes a 415-aa protein. PEBP2 alpha C forms a heterodimer with PEBP2 beta, binds to the PEBP2 site and transactivates transcription, similar to PEBP2 alpha A and PEBP2 alpha B.

Antireflection coating with fluoropolymer for a novel organic nonlinear optical crystal: 8-(4'-acetylphenyl)-1,4-dioxa-8-azaspiro[4.5]decane (ADPA)

Prior to the frequency doubling of a laser diode through a ring resonator, reflection loss on the surface of a novel organic second-order nonlinear optical crystal, 8-(4'-acetylphenyl)-1,4-dioxa-8-azaspiro[4.5]decane (APDA), was decreased. An optically flat crystal surface with a flatness of λ/10 (λ = 633 nm) and surface roughness of 1.5 nm rms was obtained when an ultraprecision diamond turning lathe was used to machine the crystal surface. After this surface was coated antireflectively with an amorphous fluorinated polymer, Teflon AF-2400, the transmittance at 810 nm was increased to 98%. A laser-diode-pumped ring resonator was built with this crystal, and a blue second-harmonic emission at 405.5 nm wassuccessfully generated.

Immunocytochemical characterization of glial fibrillary tangles in Alzheimer's disease brain

Neurofibrillary tangle is a major cytoskeletal pathology in Alzheimer's disease brains, and has been considered to develop exclusively in neuronal cells. We examined brains with Alzheimer's disease and observed argyrophilic fibrillary tangles not only in cortical neurons but also in subcortical glial cells in the frontal and temporal white matter. The tangles in glial cells were immunolabeled by antibodies against tau and ubiquitin, and double immunocytochemistry analyzed by confocal laser scanning microscopy demonstrated that the cytoplasms of tangle-bearing glia were labeled by antibodies against transferrin and 2'3'-cyclic nucleotide 3'-phosphohydrolase. Ultrastructurally, they were made up of bundles of straight filaments 16 nm in diameter and constricted filaments. These results indicate that fibrillary tangles resembling neurofibrillary tangles may develop in oligodendrocytes in brains with Alzheimer's disease and are distinguishable from glial cytoplasmic inclusions observed in multiple system atrophy brains. We referred to them as glial fibrillary tangles. Glial fibrillary tangles commonly occurred in this disease condition, and glial cells might be involved under the pathological processes similar to neuronal cells.

Pathogenesis of high-altitude pulmonary oedema: direct evidence of stress failure of pulmonary capillaries

The pathogenesis of high-altitude pulmonary oedema (HAPE) is disputed. Recent reports show a strong correlation between the occurrence of HAPE and pulmonary artery pressure, and it is known that the oedema is of the high-permeability type. We have, therefore, proposed that HAPE is caused by ultrastructural damage to pulmonary capillaries as a result of stress failure of their walls. However, no satisfactory electron microscopy studies are available in patients with HAPE, and animal models are difficult to find. Madison strain Sprague-Dawley rats show a brisk pulmonary pressure response to acute hypoxia and are susceptible to HAPE. We exposed 13 Madison rats to a pressure of 294 torr for up to 12.5 h, or 4 rats to 236 torr for up to 8 h. Pulmonary arterial or right ventricular systolic pressures measured with a catheter increased from 30.5 +/- 0.5 (SEM) in controls (n = 4) to 48 +/- 2 torr (n = 11). The lungs were fixed for electron microscopy with intravascular glutaraldehyde. Frothy bloodstained fluid was seen in the trachea of three animals. Ultrastructural examination showed evidence of stress failure of pulmonary capillaries, including disruption of the capillary endothelial layer, or all layers of the wall, swelling of the alveolar epithelial layer, red blood cells (RBCs) and oedematous fluid in the alveolar wall interstitium, proteinaceous fluid and RBCs in the alveolar spaces, and fluid-filled protrusions of the endothelium into the capillary lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathogenesis of high-altitude pulmonary oedema: direct evidence of stress failure of pulmonary capillaries

The pathogenesis of high-altitude pulmonary oedema (HAPE) is disputed. Recent reports show a strong correlation between the occurrence of HAPE and pulmonary artery pressure, and it is known that the oedema is of the high-permeability type. We have, therefore, proposed that HAPE is caused by ultrastructural damage to pulmonary capillaries as a result of stress failure of their walls. However, no satisfactory electron microscopy studies are available in patients with HAPE, and animal models are difficult to find. Madison strain Sprague-Dawley rats show a brisk pulmonary pressure response to acute hypoxia and are susceptible to HAPE. We exposed 13 Madison rats to a pressure of 294 torr for up to 12.5 h, or 4 rats to 236 torr for up to 8 h. Pulmonary arterial or right ventricular systolic pressures measured with a catheter increased from 30.5 +/- 0.5 (SEM) in controls (n = 4) to 48 +/- 2 torr (n = 11). The lungs were fixed for electron microscopy with intravascular glutaraldehyde. Frothy bloodstained fluid was seen in the trachea of three animals. Ultrastructural examination showed evidence of stress failure of pulmonary capillaries, including disruption of the capillary endothelial layer, or all layers of the wall, swelling of the alveolar epithelial layer, red blood cells (RBCs) and oedematous fluid in the alveolar wall interstitium, proteinaceous fluid and RBCs in the alveolar spaces, and fluid-filled protrusions of the endothelium into the capillary lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of diet-induced atheroma formation in transgenic mice expressing apolipoprotein E in the arterial wall

Apolipoprotein E (apoE) plays a crucial role in lipoprotein metabolism both in plasma and in peripheral tissues. To test whether apoE in the vascular wall has a direct and local effect on atherogenesis, we established transgenic mice expressing human apoE under control of H2 Ld promoter. Studies on mRNA levels and immunohistochemistry demonstrated that this line was characterized by high expression of human apoE in the arterial wall while its expression was relatively low in other tissues as compared with the respective endogenous expression of mouse apoE. They showed no difference in plasma cholesterol levels and lipoprotein profile from controls when fed both normal and atherogenic diets. However, after 24 wk of an atherogenic diet, the formation of fatty streak lesions in proximal aorta was markedly inhibited in transgenic mice as compared with controls. Both lesion area and esterified cholesterol content were < 30% of those in controls. In a tissue cholesterol labeling study with 3H-cholesterol, the specific activity of aorta cholesterol was much less in transgenic mice, suggesting that apoE enhances cholesterol efflux from the aortic wall into plasma. Thus, apoE has anti-atherogenic action which is mediated via enhancing reverse cholesterol transport from arterial wall.

Dilating effect of prostaglandin on the constricted ductus arteriosus in newborn rats

The dilating effect of prostaglandin (PG) E1 and E2 on the once-constricted ductus arteriosus (DA) was examined in newborn rats. The animals were given subcutaneously PGs 3hr after caesarean delivery. The ratio of the DA to the pulmonary artery (PA) was determined 15, 30, 60, 90 and 180 min after injection. Both PGE1 and PGE2 dilated the DA for over 90 min. The maximal effect appeared 15 or 30 min after injection. The DA/PA ratio was significantly higher in PGE2 than in PGE1. In addition, another series of newborn rats were given subcutaneously PGE2 6 hr after caesarean delivery to examine the age-related changes in the DA-dilating effect. The DA/PA ratio was significantly decreased in 6-hr-old pups than in 3-hr-old pups. These findings indicate that both PGE1 and PGE2 have a dilating effect on the once-constricted DA and that the effect decreases with time.