cDNA cloning, expression, and mutagenesis study of leukotriene B4 12-hydroxydehydrogenase

Leukotriene B4 12-hydroxydehydrogenase catalyzes the conversion of leukotriene B4 into its biologically less active metabolite, 12-oxo-leukotriene B4. This is an initial and key step of metabolic inactivation of leukotriene B4 in various tissues other than leukocytes. Here we report the cDNA cloning for porcine and human enzymes from kidney cDNA libraries. A full-length cDNA of the porcine enzyme contains an open reading frame consisting of 987 base pairs, corresponding to 329 amino acids. The human enzyme showed a 97.1% homology with the porcine enzyme. Northern blotting of human tissues revealed its high expression in the kidney, liver, and intestine but not in leukocytes. The porcine enzyme was expressed as a glutathione S-transferase fusion protein in Escherichia coli, which exhibited similar characteristics with the native enzyme. Because the enzymes have a homology, in part, with NAD(P)(+)-dependent alcohol dehydrogenases, a site-directed mutagenesis study was carried out. We found that three glycines at 152, 155, and 166 have crucial roles in the enzyme activity, possibly by producing an NADP+ binding pocket.

Prediction of disease relapse in patients with breast cancer

Among 157 breast cancer patients with median follow-up term of 120 months, we analyzed relationships of clinicopathologic factors and several prognostic factors determined histochemically with disease relapse, and we determined risk scores. Lymph-node status (p=0.0001) and microvessel count (MVC) (p=0.026) in all patients, p53 protein (p=0.0019) and MVC (p=0.001) in node-negative patients had independently significant prognostic value in predicting disease relapse. The risk scores based upon these factors had powerful predictive values for disease relapse (p=0.0001). Using these factors, we could simply and accurately identify patients with high-risk for relapse. Moreover, it might be useful for making decisions on adjuvant therapy.

Multiseptate gallbladder: biliary manometry and scintigraphy

A 30-year-old man with multiseptate gallbladder, a very rare congenital anomaly, is presented. His presenting symptom was epigastric pain. A hypoplastic gallbladder with multiple septa was demonstrated by ultrasonography and endoscopic retrograde cholangiography. An injection of cerulein reproduced pain, and simultaneous biliary manometry and scintigraphy showed impairment of gallbladder filling and emptying. Laparoscopic cholecystectomy resulted in complete relief of the pain. Biliary manometry and scintigraphy are useful to determine the operative indication in a symptomatic patient with this entity.

Alternative RNA splicing of the human endothelin-A receptor generates multiple transcripts

In order to elucidate the regulatory mechanisms of expression of the human endothelin-A receptor (hET-AR) gene, we characterized hET-AR transcripts using reverse transcriptase (RT)-PCR analysis in a variety of human tissues. RT-PCR of lung mRNA using a set of primers from exons 2 and 5 showed two lower-molecular-mass transcripts in addition to the expected fragment. When RT-PCR with primers from exons 4 and 8 was performed, no transcripts other than the expected one were detected. PCR cloning utilizing a set of primers from exons 2 and 8 which covered the entire coding sequence revealed that the cDNA clones corresponding to the two novel transcripts contained deletions of 199 bp and 327 bp respectively compared with the previously described hET-AR cDNA. Comparison of their sequences with that of the hET-AR gene showed that the deleted sequences correspond exactly to exon 4 and exons 3 and 4 respectively, indicating that these lower-molecular-mass ET-AR transcripts results from alternative RNA splicing (designated ET-AR delta 4 and ET-AR delta 3,4 respectively). Alternative splicing of exon 4 results in a transcript which would be translated into a C-terminal truncated protein containing the first, second and third transmembrane domains, while the splicing out of exons 3 and 4 would produce a protein with five membrane-spanning domains but lacking the third and fourth domains present in the ET-AR protein. An RNase protection assay revealed that ET-AR delta 4 and ET-AR delta 3,4 as well as ET-AR, transcripts were observed in various human tissues, including the lung, aorta, atrium, kidney and placenta, which are known to express ET-AR abundantly. Thus we have isolated the cDNAs of novel transcripts of hET-AR which are generated by alternative RNA splicing, and these results suggest that this alternative RNA splicing might contribute to the regulation of ET-AR gene expression.

[A case of Sjögren's syndrome with an eyelid tumor, a so-termed pseudolymphoma of the iacrimal gland]

The female subject, 64 years old, subjectively noticed a mild dryness of the eyes and bilateral, submandibular swelling in 1988. The clinical symptom was mild, and such autoantibody and hyper-gammaglobulinemia as often observed in Sjögren's syndrome were not recognized. However, by judging from the results of gum test (9 mL/10 min), salivary gland scan (Grade 2) and the labial biopsy, we diagnosed the case as Sjögren's syndrome. We then administered prednisolone at 40 mg at the onset of treatment and gradually decreasing the dosage over 3.5 years, and the symptoms improved. As an eyelid tumor in the left eye was noticed in 1991 and began to enlarge, the subject was hospitalized in June of 1992. The biopsy of the tumor (2.0 x 1.7 cm) showed marked polyclonal lymphoproliferation with lymphoid follicles which was determined by immunohistological staining. The case was a patient with a lymphoproliferative lesion from a lacrimal gland which is equal to a so-termed pseudolymphoma. Since there are some reports concerning the transition from pseudolymphoma to malignant lymphoma, this patient should be followed carefully.

Effect of in vitro and in vivo administration of dexamethasone on rat macrophage functions: comparison between alveolar and peritoneal macrophages

Resident alveolar macrophages (AMs) and peritoneal macrophages (PMs), though they originate from common precursor cells, differ morphologically and functionally. The two types of macrophages residing in different tissues may respond differently to glucocorticoids. In the present study, we compared the effects of a synthetic glucocorticoid, dexamethasone (Dex), on rat AMs and PMs with regard to their phagocytic activity and tumour necrosis factor-alpha (TNF-alpha) releasability. In vitro exposure of the macrophages to Dex caused the depression of phagocytic activity of AMs but not of PMs. In contrast, TNF-alpha releasability was depressed in the both types of macrophages, and no difference was found between AMs and PMs in their susceptibility to TNF-alpha regulation by Dex. When Dex was administered subcutaneously into rats, phagocytic activity was severely depressed in AMs but not in PMs. On the other hand, TNF-alpha releasability was depressed both in AMs and PMs by the in vivo Dex administration. The depression in PMs, however, was transitory and less severe than that in AMs. These results suggest that alveolar macrophages and peritoneal macrophages differ intrinsically in responses to glucocorticoid, and that the cell location and the cell's microenvironment can also modulate the effects of glucocorticoid on macrophage functions.

Case report: imaging of Takayasu arteritis in the acute stage

We report a case of Takayasu arteritis (TA) in the acute stage. The case is unique in two points. First, the diagnosis of Takayasu arteritis was initially suspected from a subtle finding on plain radiography. Second, thickening of the aortic and pulmonary arterial walls was demonstrated by computed tomography and magnetic resonance imaging in the acute non-pulseless stage of the disease.

Recovery of macromolecular activators of phagocytosis from platelets (MAPP) producing and releasing function in stored human platelets

Macromolecular activators of phagocytosis from platelets (MAPP) were not released from platelets prepared from platelet concentrates (PC) obtained after anticoagulation with CPD solution and stored for more than 48 h. The MAPP activity which had escaped into the plasma disappeared after 72 h of storage. After incubation in dialyzed and Ca(2+)-supplemented plasma prepared from the same PC or from fresh peripheral blood, the platelets obtained after storage for 72 h released both MAPP (l-MAPP and s-MAPP) upon thrombin stimulation. Gel filtration studies of the plasma revealed that l-MAPP and s-MAPP were produced from the platelets incubated in plasma fractions corresponding to l-MAPP and s-MAPP, respectively. These observations suggest that platelets accumulate precursors of MAPP, pre-MAPP comprising pre-l-MAPP and pre-s-MAPP, in the presence of Ca2+, and produce and release MAPP when stimulated with thrombin.

Augmented expression of obese (ob) gene during the process of obesity in genetically obese-hyperglycemic Wistar fatty (fa/fa) rats

Expression of the obese (ob) gene is up-regulated in the adipose tissue in several obese rodent models. To study the regulation of the ob gene expression during the development of obesity, we examined the ob gene expression in genetically obese-hyperglycemic Wistar fatty (fa/fa) rats at several stages of obesity. The ob mRNA levels in the adipose tissue from Wistar fatty rats was unequivocally augmented and continued to rise in the process of obesity. Furthermore, the ob gene expression in this obese model was much more rapidly enhanced in the mesenteric fat than in the subcutaneous fat. Moreover, the ob gene expression was more greatly augmented in the mesenteric fat than the lipoprotein lipase gene expression. These results suggest the presence of obesity-linked and region-specific regulation of the ob gene expression.

Reproductive and developmental toxicity studies of toluene. II. Effects of inhalation exposure on fertility in rats

Male and female Sprague-Dawley rats were exposed to toluene vapor at 600 and 2000 ppm for 6 h/day, and effects on their fertility were investigated. Females were exposed from 14 days before mating until day 7 of gestation. Males were exposed for a total of 90 days, including the mating period; treatment was begun 60 days before pairing, and toxicity with respect to testicular and reproductive functions was examined. In females of the 2000 ppm-treated group, salivation and lacrimation that may have been caused by CNS depression were observed starting 20 days after exposure. Although no abnormalities were seen in mating behavior or fertility, fetal mortality and the number of dams with dead fetuses increased in the 2000 ppm group. In the males exposed to 2000 ppm toluene for 90 days, an increase in kidney weights and a decrease in thymus weights were observed. Basophilic changes and necrosis of kidney tubules were greater at the higher exposure level. Additionally, decreases in the weights of the epididymides and spermatic count were observed, indicating toxicity of toluene to the male reproductive system in vivo for the first time. In conclusion, embryo-fetal toxic effects were apparent in female rats exposed to toluene before and during the early stage of pregnancy. Subacute exposure to a high level (2000 ppm) of toluene vapor elicited mild toxic changes in the kidneys, thymus, and reproductive organs of males. Toxic effects on fertility and reproduction were thus demonstrated not only in females but also in males exposed to toluene vapor in the present study.

Regulation of very-low-density lipoprotein receptor in hypertrophic rat heart

To elucidate the regulation of very-low density-lipoprotein (VLDL) receptor, we have studied its gene expression in the heart of spontaneously hypertensive rats-stroke prone (SHR-SP, an animal model for hypertension-induced cardiac hypertrophy) compared with Wistar-Kyoto rats. RNase protection assay showed that ventricular VLDL receptor mRNA falls to 41% of normal levels at 4 weeks when hypertension is not yet fully developed, and drops further to 14% at 13 weeks, when cardiac hypertrophy is established. Lipoprotein lipase mRNA decreases in parallel with VLDL receptor mRNA. In cultured neonatal rat ventricular cardiomyocytes, VLDL receptor mRNA decreases in parallel with the process of cardiocyte hypertrophy during the 24 hours after treatment with 10-8 mol/L endothelin-1, falling to 40% of the initial value. These results demonstrate that there is downregulation of VLDL receptor gene expression in cardiac hypertrophy both in vivo and in vitro and suggest that the regulation of the VLDL receptor is possibly linked with the switch in energy substrate from lipid to glucose known to occur in cardiac hypertrophy.

Hypomelanosis of Ito associated with neuroblastoma

We report a patient with hypomelanosis of Ito associated with neuroblastoma. Though not previously reported, the association is plausible since both conditions are forms of "neurocristopathy".

Brain dysplasia associated with Larsen-like syndrome

We present an autopsy case of Larsen-like syndrome with unusually severe neurologic complications. The patient, a 3-year-old girl, manifested severe psychomotor retardation, tetraplegia, and intractable partial seizures as well as multiple joint dislocations with other skeletal deformities, minor external anomalies, and laryngotracheomalacia. Neuropathological examination of the brain revealed (1) cortical dysgenesis in the bilateral perisylvian region; (2) protrusions of the brain parenchyma into the subarachnoid space, (3) abnormal arrangement of olivary neurons, (4) dilation of the lateral ventricles with subventricular gliosis and multiple glial nodules, (5) hypoplasia of the cerebral white matter with subcortical astrocytosis, and (6) necrotic change in Sommer sector of the hippocampus. There were no microscopic abnormalities in the mesenchymal tissue of the brain (i.e., vascular walls and the meninges). Cortical dysgenesis in the perisylvian region was characterized by a zonal heterotopia of pyramidal and granule neurons in the molecular layer, which clinically may be closely related to intractable partial seizures in the orofacial area. Findings 1, 2, and 3 may represent a disturbance of neuroblast migration, speculated to have occurred during the latest stage of migration (around 20-25 weeks gestation). There are few published reports describing the combination of Larsen-like syndrome and brain dysplasia. Correlation of brain dysplasia with congenital skeletal abnormalities is unclear in our patient. We speculate that systemic hypoxic-ischemic insults during the second half of gestation and/or some genetic factors might be possible causes of brain dysplasia.

The natriuretic peptide family

The natriuretic peptide system is a complicated system comprising at least three endogenous peptides (atrial natriuretic peptide, brain natriuretic peptide and C-type natriuretic peptide) and three receptors [the atrial natriuretic peptide-A receptor (guanylyl cyclase A), the atrial natriuretic peptide-B receptor (guanylyl cyclase B) and the clearance receptor]. The accumulated evidence indicates that this system is implicated in the control of blood pressure, body fluid homeostasis and vascular remodelling as cardiac hormone and local regulator.

Endothelin-1-like immunoreactivity and endothelin receptors in the human placenta from normotensive and hypertensive pregnancies

The levels of endothelin-1-like immunoreactivity (ET-1-LI) and characteristics of endothelin receptors in the chorionic villous tissue of human placenta were determined. The ET-1-LI level in chorionic villous tissue obtained from normal term placenta was 2,450 +/- 940 pg/g wet weight (mean +/- SD, n = 4). Further analysis using gel permeation chromatography and reverse-phase high performance liquid chromatography showed that the main ET-1-LI constituent of ET-1-LI in this tissue was ET-1. Scatchard analysis of [125I]ET-1 binding to the membrane fraction of chorionic villous tissue obtained from term placenta showed high affinity receptor sites with an apparent dissociation constant (Kd) of 23.6 +/- 11.1 pM and a Bmax value of 388 +/- 238 fmol/mg protein (n = 5). The same binding study with [125I]ET 3 showed a Kd of 13.9 +/- 3.8 pM and a Bmax value of 176 +/- 78 fmol/mg protein (n = 5). These results suggest that both ET-A and ET-B receptors (ET-AR and ET-BR) are expressed in chorionic villous tissue. This finding was further confirmed by Northern blot analysis showing the expression of both ET-AR and ET-BR mRNAs in this tissue. ET-1-LI in the umbilical venous plasma of the newborns from women with pregnancy-induced hypertension (PIH) (38.3 +/- 10.4 pg/mL, n = 5) was significantly (P < 0.05) higher than that in the normal newborns from normotensive pregnant women (26.3 +/- 5.2 pg/mL, n = 12). However, in placental chorionic villous tissue obtained from PIH women, both ET-1-LI level and ET binding profile were not different from those in chorionic villous tissue from normotensive pregnant women. These results suggest that the abundant ET-ET receptor system is present in the placental chorionic villous tissue and that this system is not the major factor of the pathogenesis of placental dysfunction occurring in PIH because these systems are similar in normotensive and hypertensive pregnancies.

Effect of penicillin G on the electroporation of Rhodococcus rhodochrous CF222

Suitable conditions for the introduction of bacteriophage DNA into cells of Rhodococcus rhodochrous CF222 by electroporation were established, and penicillin G was found to enhance the transfection frequency. When conditions optimal for the parental strain were applied to its colony-morphological mutants, different transfection frequencies were observed. Penicillin G enhanced the transfection frequency of smooth and mucoidal mutants but not of rough mutants.

Intravitreal transforming growth factor-beta 2 decreases cellular infiltration in endotoxin-induced ocular inflammation in rabbits

Transforming growth factor-beta (TGF-beta), a multifunctional cytokine which has been identified in normal and inflamed ocular fluids, may play a role in the evolution of inflammatory ocular lesions. In this study we utilized a rabbit model of LPS-induced uveitis to determine if exogenous TGF-beta 2 could alter its course. Recombinant TGF-beta 2 (1-2000 ng), LPS (10 or 20 ng), or TGF-beta 2 (100 ng) plus LPS (10 ng) were injected intravitreally in one eye of a New Zealand white rabbit and the contralateral eye served as a paired control which received an equal volume of vehicle. The uveitic response was assessed by biomicroscopic examination of the anterior uvea and analysis of protein and cells in the aqueous humor. Ocular tissues were processed for histologic, immunohistochemical and in situ hybridization analyses. Rabbits injected with doses of TGF-beta 2 > or = 500 ng developed a mild uveitic response, compared to LPS alone, accompanied by expression of IL-1 beta mRNA and protein in the anterior uvea. Interestingly, rabbits coinjected with LPS (10 ng) and a nonuveitic dose (100 ng) of TGF-beta 2 exhibited a similar increase in ocular vascular permeability, but a decrease in inflammatory cell infiltration into the anterior uvea and aqueous humor (1185 +/- 117 versus 2465 +/- 176; p < 0.05). No evidence of inflammation was observed in eyes injected with 100 ng TGF-beta 2 alone. Similar to other models of inflammation, TGF-beta may interrupt the cascade of events leading to ocular inflammation, thereby suggesting therapeutic potential.

Two cases of mature B-cell acute lymphocytic leukemia with normal karyotype in adults

Acute lymphocytic leukemia with mature B-cell phenotype (B-ALL) is a rare type of ALL. Although B-ALL cells commonly have a characteristic chromosomal translocation that includes 8q24 (the location of the c-myc protooncogene), the leukemic cells of the two patients reported in this paper showed normal karyotypes. This finding was confirmed by Southern blot analysis of bone marrow cells in case 1. A c-myc probe was used, and no rearrangement or amplification of c-myc expression was found; B-ALL with the translocation including 8q24 is reported to show high levels of expression of rearranged c-myc. Investigation of anti-Epstein-Barr virus (EBV) antibody revealed that both cases 1 and 2 had a past history of EBV infection. However, at least in case 1, integration of the EBV genomic DNA into the leukemic cells was not detected by the polymerase chain reaction in which specific primers for EBV were employed. The difference in pathophysiology between B-ALL with and without the 8q24 translocation is unclear, however, the prognosis of the two patients with B-ALL with the normal karyotype was as poor as that of B-ALL with the chromosomal translocation.

Myelofibrosis secondary to renal osteodystrophy

A hemodialyzed women with secondary hyperparathyroidism who recovered well from myelofibrosis after a total parathyroidectomy with autotransplantation of parathyroid tissue to the forearm (PTx) is described. Before the operation, she had received regular transfusions to maintain an adequate hematocrit even under recombinant human erythropoietin (rhEpo) therapy. She showed splenomegaly and leukoerythroblastosis was present in her peripheral blood. A bone marrow biopsy and bone marrow scintigraphy confirmed the diagnosis of myelofibrosis. After PTx, her hematocrit gradually increased without any transfusion. It has been maintained around 35% now 16 months since the operation. Her spleen has also gradually decreased in size. In addition, no leukoerythroblastosis has been found in the peripheral blood. Serial follow-up scintigraphy of bone marrow revealed a decline in extramedullary hematopoiesis. These findings indicated that her myelofibrosis was the result of secondary hyperparathyroidism, and that this complication is potentially reversible if accurate treatment is given. Physicians dealing with the end-stage renal disease should be aware of this complication to avoid additional transfusions.

Binaural interaction of stapedius reflex

It is known that stapedius reflex (SR) shows bilateral interaction and that its center is located in the brainstem. In the present study, the pattern of SR was compared in two different conditions, either with binaural acoustic stimuli or with monaural stimuli using the impedance measurement method. When the sound source was placed in front of the head model, the amplitude of impedance change was higher in the binaural hearing condition than in the monaural condition, suggesting bilateral superposition. When the sound source was placed laterally to the head model, the amplitude of impedance change was higher in the ipsilateral ear than in the contralateral ear in the binaural condition. In the monaural condition, the amplitude of impedance change in the ipsilateral ear was as high as that obtained in the ipsilateral ear in the binaural condition, whereas it was markedly low in the contralateral ear. It is assumed that sense of sound direction cannot be well maintained without binaural interaction of SR.

Effects of formaldehyde vapor on the nasal cavity and lungs of F-344 rats

Histopathological and biochemical examinations of the nasal cavity and lungs of rats inhaling 145.6 ppm (high-dose) or 15.0 ppm (low-dose) formaldehyde vapor for 6 h revealed dose-related damage. The contents of non-protein SH groups (NPSH) in the nasal mucosa and lung, and lipid peroxide (LPO) in the nasal mucosa were decreased, whereas LPO was increased in the lung. The contents of triglyceride in the lung tissue and lavage, and free cholesterol in the lung were decreased, providing evidence of a suppression of surfactant production. Exposure-related changes in the nasal turbinates, trachea, and lung included hyperkeratosis of the squamous epithelium, increased secretion, and desquamation of ciliated and mucosal cells. Under the present experimental conditions, 145.6 ppm formaldehyde vapor was found to strongly affect the exposed tissues. Changes in lipid peroxide were dependent on the level of exposure.