Functional pulmonary surfactant deficiency and neonatal respiratory disorders

The pathophysiology of functional deficiency of pulmonary surfactant in the neonatal respiratory disorders represented by MAS, hemorrhagic lung edema and ARDS was discussed. The removal of inhibitor(s) is the cardinal procedure for MAS and the lavage with surfactant solution seems to be promising. In case of replacement therapy, we should consider using a different dose compared to the one used in RDS due to lung immaturity, in order to optimize results.

Self-renewal and differentiation of a basic fibroblast growth factor-dependent multipotent hematopoietic cell line derived from embryonic stem cells

Despite the accumulation of informat on on the origin of hematopoietic stem cells, it is still unclear how these cells are generated in ontogeny. Isolation of cell lines equivalent to early embryonic hematopoietic progenitor cells can be helpful. A multipotent hematopoietic progenitor cell line, A-6, was isolated from H-1 embryonic stem (ES) cells. The self-renewal of A-6 cells was supported by basic-fibroblast growth factor (b-FGF) and their differentiation into definitive erythroid cells, granulocytes and macrophages was induced after co-culture with ST-2 stromal cells. A-6 cells were positive for the surface markers of hematopoietic stem cell, c-kit, CD31, CD34, Flt3/Flk2, PgP-1, and HSA, but were negative for that of the differentiated cells. Reverse transcription-polymerase chain reaction analysis showed that A-6 cells produced mRNA from SCL/tal-1 and GATA-2 genes. Among various cytokines examined, on y stem cell factor (SCF) and Flt3/Flk2 ligand (FL) supported the proliferation of A-6 cells instead of b-FGF. The FL, as well as b-FGF, supported the self-renewal of A-6 cells, whereas SCF induced differentiation into myeloid cells. A-6 cells will be useful for the characterization of hematopoietic progenitor cells derived from ES cells and provide a model system to realize the control mechanisms between self-renewal and different ation of hematopoietic stem cells.

Morphological characteristics of the dermal papillae in the development of pressure sores

Mechanisms of skin break down in the development of human pressure sores are still unclear. This study was undertaken to clarify the morphological characteristics of the dermal papillae in the skin associated with pressure sores. Skin tissues were excised from the sacrum of a Japanese subject post mortem, where a superficial pressure sore had developed. Light microscopic and transmission and scanning electron microscopic examinations were performed. It was found that the atrophic, irregular contour and alignment of the dermal papillae were characteristic of the boundary area between healthy and damaged areas. In addition, a relatively dense network of collagen fibres in the papillary layer of the boundary area was observed when compared with the healthy area. These findings suggest that the morphological changes of the papillae observed in the boundary area affect microcirculation, impairing tissue viability by inhibiting nutritive blood supply and by accumulating metabolic byproducts which predispose to tissue damage.

Inhibition of gene expression from the human c-erbB gene promoter by a retroviral vector expressing anti-gene RNA

Anti-gene is a potent inhibitor of transcriptional promoter activity and subsequent gene expression. This property has been exploited to suppress the expression of a variety of oncogenes for regulating tumor proliferation or viral activities. In this paper, we describe a novel retroviral vector designed to express human c-erbB anti-gene RNA and to reduce the promoter activity in the cells. Mouse fibroblast NIH3T3 cells were stably transfected with an expression construct containing a truncated human c-erbB gene promoter fused to the firefly luciferase reporter gene. Infection into these cells of the c-erbB anti-gene retroviral vector targeted to the 26 bp pyrimidine-rich element in the human c-erbB gene promoter resulted in a dose-dependent decrease in the luciferase activity of the cells. Retroviral vector expressing anti-gene RNA may be useful as an alternative program of gene regulation in the cells.

Roles of the Pas1 and Par2 genes in determination of the unique, intermediate susceptibility of BALB/cByJ mice to urethane-induction of lung carcinogenesis: differential effects on tumor multiplicity, size and Kras2 mutations

The C3H/HeJ (C3H), A/J and BALB/cByJ (BALB) mouse strains are respectively resistant, sensitive and intermediate regarding the induction of lung tumors by urethane. The phenotypic difference between C3H and A/J is largely determined by the Pas1 (Pulmonary adenoma susceptibility 1) gene on chromosome 6, the A/J allele of which dominantly increases the tumor burden. We recently found that BALB mice possess a unique lung tumor resistance gene on chromosome 18, designated Par2 (Pulmonary adenoma resistance 2), which partially, but dominantly suppresses the sensitive phenotype of A/J mice (Oncogene 13: 1599-1604, 1996). It has, however, remained unclear why BALB mice carrying the Par2 gene are significantly more sensitive to urethane-induced lung carcinogenesis than C3H mice that have no dominant lung tumor resistance genes. In the present study, using (C3H x BALB)F1 x C3H backcross mice treated with urethane, we demonstrated that BALB mice possess the disease allele of the Pas1 gene despite their 15-fold more resistance relative to A/J mice (LOD = 22.6). The BALB Par2 allele only significantly reduced the mean lung tumor multiplicity (LOD = 4.4) in the backcross population carrying the BALB allele of Pas1, indicating that the intermediate BALB phenotype may at least in part be the result of interactions between these two dominant genes. While the BALB Pas1 allele increased both the mean multiplicity and size of lung tumors, the BALB Par2 allele affected only the mean tumor multiplicity, implying that they are involved in different stages of multi-step lung carcinogenesis. In addition, we found that 68% of lung tumors from the BALB Pas1-positive backcross mice contained activating point mutations of the Kras2 oncogene, tightly linked to the Pas1 locus, whereas these genetic alterations were absent in tumors from BALB Pas1-negative mice. The Par2 genotype exhibited no effect on this parameter. Since the activating point mutations were observed exclusively in the BALB allele as already reported with lung tumors in (C57BL/6J x BALB/cJ)F1 mice, BALB Pas1 or possibly Kras2 itself may confer selective growth advantage on the affected urethane-initiated lung lesions.

Loss of heterozygosity at loci on chromosome 4, a common genetic event during the spontaneous immortalization of mouse embryonic fibroblasts

Spontaneously immortalized fibroblast cell lines derived from embryonic tissues of C3D2F1, mice were analyzed for loss of heterozygosity (LOH) at multiple chromosomal loci to identify candidate suppressor loci for immortalization. Among 47 simple sequence repeat (SSR) loci selected for screening, those on chromosome 4 exhibited an exceptionally high LDH incidence of up to 89%. Only four other chromosomes (8, 11, 12, and 18) showed LOH, with the highest incidence being 33%. To further localize candidate suppressor genes on mouse chromosome 4, detailed deletion mapping was performed with 18 cell lines and 14 SSR markers. The greatest LOH incidence (94%) was observed at the D4Mit14 locus located on distal chromosome 4, indicating that a major suppressor gene resides in this region. On the other hand, at the D4Mit77 locus, 30 cM proximal to the D4Mit14 locus, we found the SSR to be homozygously lost in 39% of the cell lines. Because the D4Mit77 is tightly linked to the tumor suppressor gene p16, for which homozygous deletion has been reported in various human tumor cell lines, we also examined our fibroblast cell lines for gross aberrations of the p16 gene by using the Southern blot method. The p16 gene was found to be homozygously deleted in 56% of the cell lines. Although this result implies that the p16 gene plays a role as a suppressor gene for immortalization, the combined incidence of LOH and homozygous deletion at the D4Mit77 locus was 72%, which is significantly lower than the observed incidence at the D4Mit14 locus. Consequently, we concluded that immortalization of mouse embryonic fibroblasts may involve more than one suppressor gene on chromosome 4.

Genetic dissection of susceptibility to murine ovarian teratomas that originate from parthenogenetic oocytes

The LT/Sv mouse strain is characterized by its abnormally high incidence of spontaneous ovarian teratomas. These tumors have been shown to originate from parthenogenetic oocytes, which are spontaneously induced to divide. Both spontaneous parthenogenesis and ovarian teratomas are extremely rare for other mouse strains, including C57BL/6J. To identify the genes responsible for this unique phenotype of female LT/Sv mice, we performed linkage analysis of female (C57BL/6J x LT/Sv)F2 mice. A locus on chromosome 6 designated Ots1 (ovarian teratoma susceptibility) was identified as the single major locus that increases the frequency of teratomas in a semidominant manner.

Successful hematopoietic reconstitution by transplantation of umbilical cord blood cells in a transfusion-dependent child with Diamond-Blackfan anemia

A 4-year-old boy with Diamond-Blackfan anemia and a history of multiple transfusions underwent umbilical cord blood transplantation from his HLA-identical female sibling born by vaginal delivery at 38 weeks. The patient was prepared with busulfan, cyclophosphamide and antilymphocyte globulin. Methotrexate and cyclosporin A were given for the prophylaxis of GVHD. Regimen-related toxicity was not observed and successful engraftment occurred, including the erythroid series. No evidence of acute or chronic GVHD has been observed for 14 months after transplantation. This is the first case of successful umbilical cord blood transplantation to a patient with Diamond-Blackfan anemia.

Role of urinary trypsin inhibitor in the maintenance of pregnancy in mice

OBJECTIVE

To investigate the mechanisms whereby urinary trypsin inhibitor prevents lipopolysaccharide-induced preterm delivery in mice.

METHODS

On day 15 of pregnancy, C3H/HeNCrg female mice impregnated by Crg:B6D2F1 male mice were treated intraperitoneally with lipopolysaccharide (50 micrograms/kg, twice at a 3-hour interval) to induce preterm delivery. Urinary trypsin inhibitor (2.5 x 10(4), 7.5 x 10(4), or 25 x 10(4) units/kg, ten times at 1-hour intervals) or saline solution was administered intraperitoneally to the animals.

RESULTS

The incidence of preterm delivery was significantly decreased on a dose-related basis by urinary trypsin inhibitor treatment. Urinary trypsin inhibitor prevented the morphologic and functional changes in fetal membranes and cervical ripening preceding the onset of preterm delivery. Urinary trypsin inhibitor also suppressed the increase in plasma and amniotic fluid concentrations of interleukin-1 alpha, interleukin-6, and tumor necrosis factor-alpha after the lipopolysaccharide dosing in this animal model for preterm delivery.

CONCLUSION

Urinary trypsin inhibitor prevents the pathogenicity of preterm delivery through the suppression of cytokine production.

Identification of the Par2 (Pulmonary adenoma resistance) locus on mouse chromosome 18, a major genetic determinant for lung carcinogen resistance in BALB/cByJ mice

The A/J mouse strain is 14 times more susceptible to urethane-induction of lung carcinogenesis than the BALB/cByJ strain (BALB). The relative resistance of BALB is dominant over the high sensitivity of A/J, since (BALBxA/J)F1 mice are phenotypically similar to the parental BALB mice. BALB mice must thus possess modifier genes suppressing phenotypic expression of the Pas (Pulmonary adenoma susceptibility) genes, which are known to be dominant genetic determinants for lung carcinogenesis in A/J mice. In order to genetically dissect the dominant resistance of the BALB mouse, we performed a linkage analysis to chromosomally map modifier genes by using 130 (A/JxBALB)F1xA/J backcross mice. Each backcross mouse was injected i.p. with urethane (1 mg/g bw) at 6 weeks of age and lung tumors were enumerated after 120 days. When the backcross mice were genotyped at multiple simple sequence repeat marker loci distributed on all the chromosomes, a significant linkage between the presence of a BALB allele and resistance to lung tumor induction was found on distal chromosome 18 (maximum LOD = 12.2). Thus, distal chromosome 18 of the BALB mouse contains a modifier gene for lung carcinogenesis: The locus, designated Par2 (Pulmonary adenoma resistance), accounted for 38% of the phenotypic variance in the backcross population, indicating a major role in protection against lung tumor development.

Usefulness of a new tactile sensor for measurement of uterine cervical ripening in mice in a quantitative and noninvasive manner

OBJECTIVE

The purpose of this study was to establish a method with a new tactile sensor for determining in a quantitative and noninvasive manner the extent of uterine cervical ripening.

STUDY DESIGN

We used a newly designed tactile sensor to measure the softness of the cervix in untreated nonpregnant, pregnant, parturient, and nursing mice and then on day 15 of gestation in pregnant mice treated with dehydroepiandrosterone sulfate or Escherichia coli lipopolysaccharide. Additionally, to elucidate the correlation between the extent of cervical softness and its morphologic changes, we observed microscopically the uterine cervices.

RESULTS

The hardness of the murine cervix decreased with the progression of pregnancy and became minimal at delivery. We demonstrated for the first time with a tactile sensor for measuring hardness that dehydroepiandrosterone sulfate and lipopolysaccharide significantly decreased the stiffness of the murine cervix. These findings were supported by the morphologic observations on the cervices.

CONCLUSIONS

These results show that the tactile sensor for measuring hardness makes it possible to determine the extent of cervical ripening quantitatively rather than qualitatively. We consider that cervical ripening determined objectively in this manner is a good parameter to predict the onset of preterm delivery.

Detection by polymerase chain reaction of wild-type measles virus genome in the cerebrospinal fluid of a patient with SSPE who had received measles vaccine

BACKGROUND

Previous studies have reported that approximately 4-5% of patients with subacute sclerosing panencephalitis (SSPE) were given measles vaccination but had no history of natural measles. However, in the case who received measles vaccine, it has been extremely difficult to determine whether the actual cause of SSPE is the inoculated vaccine virus or not.

OBJECTIVES

To detect the measles virus genome in a patient with SSPE and to analyze its nucleotide and deduced amino acid sequence.

STUDY DESIGN

We applied the polymerase chain reaction (PCR) to detect the measles virus genome in specimens from a 12-year-old boy with SSPE who had received measles vaccine 10 years before and had no history of apparent natural measles. The oligonucleotide primers for PCR were prepared based on the nucleotide sequence of the F and NP genes of the measles virus Edmonston strain.

RESULTS

F and NP genes were detected in both the cerebrospinal fluid and peripheral blood lymphocytes. Nucleotide and deduced amino acid sequence analysis of the F gene showed that the patient's virus was different from that of the vaccine strain. Judging from these results, it was likely that the SSPE-associated strain in this case was derived from the wild-type rather than the vaccine strain.

CONCLUSIONS

PCR is a useful method to establish a definitive diagnosis of SSPE and to study the nature of the SSPE-associated virus.

Repeated administration of low-dose lipopolysaccharide induces preterm delivery in mice: a model for human preterm parturition and for assessment of the therapeutic ability of drugs against preterm delivery

OBJECTIVE

Our purpose was to establish a new animal model for human preterm delivery for assessment of the protective effect of drugs against preterm delivery.

STUDY DESIGN

C3H/HeN, C3H/HeN, and BALB/c female mice impregnated by C3H/HeN, B6D2F1, and B6D2F1 male mice, respectively, were treated intraperitoneally with Escherichia coli lipopolysaccharide (0 to 100 microgram/kg, single dose or repeated doses at 1- to 6-hour intervals) on days 12 through 17 of pregnancy. On day 15 of pregnancy, the C3H/HeN females that had been impregnated by B6D2F1 males and administered lipopolysaccharide were treated intraperitoneally with indomethacin (1000 microgram/kg), ritodrine hydrochloride (1000 microgram/kg), urinary trypsin inhibitor (25 x 10(4) units/kg), or gabexate mesylate (100 mg/kg); preterm or term delivery was recorded for these mice.

RESULTS

C3H/HeN females impregnated by B6D2F1 males revealed the highest (100%) incidence of preterm delivery when the females were treated with 50 microgram/kg lipopolysaccharide twice at a 3-hour interval on day 15 or 17 of pregnancy. Indomethacin and urinary trypsin inhibitor used separately significantly decreased the incidence of preterm delivery, but only urinary trypsin inhibitor, and not any of the other drugs, significantly increased the incidence of term delivery in the mice.

CONCLUSION

A new animal model for investigation of preterm delivery was established, and its usefulness for assessment of the protective effect of drugs against preterm delivery was demonstrated.

Functional assessment of the stratum corneum under the influence of oral aromatic retinoid (etretinate) in guinea-pigs and humans. Comparison with topical retinoic acid treatment

Clinically we have noted that the skin of patients treated with long-term oral etretinate becomes uniformly soft and smooth to touch, like facial skin that becomes smoother and less wrinkled following treatment with topical tretinoin. This suggests that retinoids, whether used systemically or topically, alter the physical properties of the skin, particularly of the stratum corneum (SC). To study the influence of retinoids on the SC, we serially assessed the functional properties of the SC non-invasively in retinoid-treated humans and experimental animals. SC hydration and barrier function were assessed by measurement of high-frequency conductance and transepidermal water loss (TEWL), respectively. Daily application of topical retinoic acid creams was found to rapidly induce a time- and dose-dependent, linear increase in SC hydration of the forearm skin of healthy adults over a 2-week period and to compromise its water barrier function in a similar fashion. Systemic administration of high-dosage etretinate, 4 or 8 mg/kg/day, to guinea-pigs also induced dose-dependent increases in both SC hydration and TEWL measured on the plantar skin after 1 month. Moreover, in the animals given etretinate 4 mg/kg/day we confirmed a slight but significant decrease in the number of cell layers of the plantar SC. Likewise, patients with various dermatoses began to show similar functional changes of the SC in the uninvolved skin of the flexor surface of the forearms 3 weeks after the start of oral etretinate treatment, consisting of 50 mg daily for 2 weeks, followed by gradual dose tapering.(ABSTRACT TRUNCATED AT 250 WORDS)

[Investigation of lipid peroxidation in regenerating rat liver]

The purpose of this study was to estimate the effects of lipid peroxidation in regenerating rat liver. Partial 70% hepatectomy was performed in rat according to Higgings and Anderson. EPC (alpha Toc: Ascorbic acid = 6:4, radical scavenger) was injected intravenously (5mg/kg weight) one hour before operation. Lipid peroxidation in regenerating liver reached a peak at 24 hours after operation. The administration of EPC markedly suppressed the increase of lipid peroxide in the plasma and remnant liver and that of GPT after hepatectomy, with subsequent good liver regeneration ratio. Moreover, the pretreatment with EPC remarkably elevated the activity of thymidine kinase (index of DAN synthesis). The EPC administration had not notable effects on the level of plasma ketone body ratio in animal but pathologically caused early advent of glycogen granule in the remnant liver tissue after partial hepatectomy, which reflected restoration of mitochondrial energy level. The results of the present study suggest that scavenger may be useful not only for impairment of liver dysfunction but also for recovery of mitochondrial energy level and DNA synthesis after liver resection.

Synthesis and biological activities of optical isomers of 2-(4-chlorophenyl)-5,6-dihydro-(1)benzothiepino[5,4-c]pyridazin-3(2H)-o ne 7-oxide

Two enantiomers of 2-(4-chlorophenyl)-5,6-dihydro-(1)benzothiepino[5,4- c]pyridazin-3(2H)-one 7-oxide ((+/-)-1: Y-23684) were synthesized in high yields by asymmetric oxidation of the synthetic precursor (2) using modified Sharpless reagent. Among the oxidants tested, cumene hydroperoxide (CHP) gave the highest optical and chemical yields, while tert-butyl, tert-amyl, and 1,1,3,3-tetramethylbutyl hydroperoxides did not show such high enantio-selectivities. The absolute configuration of (+)-1 enantiomer synthesized from 2, Ti(O-iso-Pr)4, (-)-diethyl tartarate, and CHP was determined to be S by X-ray crystallographic analysis. Both enantiomers, S-(+)-1 and R-(-)-1, and (+/-)-1 had approximately equivalent in vivo activities to antibicuculline test in mice and anticonflict test in rats, although S-( + )-1 showed about three times higher affinity to benzodiazepine receptor than R-(-)-1 in [3H]diazepam binding assay.

Polymorphonuclear leukocyte function and serum opsonic activity in surgical patients

Thirty-six patients who underwent major surgery were studied in order to clarify the perioperative changes in polymorpho - nuclear leukocyte (PMNL) function and serum opsonic activity. In patients without postoperative infection, the PMNL phagocytic-bactericidal capacity and plasma elastase levels significantly increased, while the serum opsonic index remarkably decreased just after surgery, however, all returned to the preoperative levels within 1 or 2 weeks. Conversely, in patients with postoperative infection, the PMNL bactericidal capacity and plasma elastase levels remained at high levels even after 1 or 2 weeks, while the PMNL phagocytic capacity and serum opsonic index substantially decreased after 2 weeks compared with the patients without postoperative infection. Plasma leukotriene B4, which is a potent chemo-attractant for PMNL, noticeably decreased in the patients with postoperative infection on the first postoperative day compared with that in the patients without postoperative infection. Our data suggests that the most important predisposing factors to postoperative infection may be a depressed PMNL phagocytic capacity and a lower serum opsonic activity after surgery, and that the increased PMNL bactericidal capacity and high plasma elastase levels during postoperative infection may contribute to the susceptibility to multiple organ failure.

Studies on the synthesis of condensed pyridazine derivatives. IV. Synthesis and anxiolytic activity of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4- c]pyridazin-3(2H)-ones and related compound

A series of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4-c]pyridazin-3(2H)- ones and related compounds were synthesized and evaluated for their ability to displace 3H-diazepam from rat brain membranes in vitro, and to prevent bicuculline induced convulsions in mice in vivo. Compounds with a 4'-methoxyphenyl (36) or 4'-chlorophenyl group (37, 39--42) as 2-aryl substituents showed prominent activities in both the in vitro and in vivo tests. Among them, 2-(4'-chlorophenyl)-5,6-dihydro- (37) and 2-(4'-chlorophenyl)-5,6-dihydro-10-fluoro-(1)benzothiepino[5,4-c]+ ++pyridazin- 3(2H)-one 7-oxides (41) showed activity twice as potent as diazepam in an anticonflict test (Vogel type, rats) while exhibiting less muscle relaxation (rotarod test, mice) and augmentation of gamma-aminobutyric acid-induced chloride current (Icl) in isolated frog sensory neurones than diazepam. Compound 37 (Y-23684) was selected from this series as a candidate for further development. The structure-activity relationships are discussed.

Vertebrate collagenase inhibitor. II. Tetrapeptidyl hydroxamic acids

To develop a potent and specific collagenase inhibitor, a series of tetrapeptidyl hydroxamic acids were synthesized, based on the previous findings with tripeptidyl derivatives (Chem. Pharm. Bull., 38, 1007-1011, 1990). Among the series of tetrapeptidyl derivatives synthesized, R-Gly-Pro-Leu-Ala-NHOH and R-Gly-Pro-D-Leu-D-Ala-NHOH were found to be highly specific and potent inhibitors against vertebrate collagenase with an IC50 of 10(-6) M order, where R stands for Boc or acyl group. Analysis of their structure-activity relationships showed a characteristic feature of the substrate-binding site of collagenase as follows: 1) the S1 subsite forms a shallow hydrophobic pocket, although glycine residue corresponds to the subsite of the natural collagen substrate: 2) the S2 subsite constitutes a bulky pocket with less requirement for hydrophobicity: 3) the S3 subsite preferentially accommodates Pro residue: and 4) the accommodation of the P4-P1 subsites of peptidyl collagenase inhibitor to the S4-S1 subsites is required to form a tight binding of its hydroxamic acid moiety to the zinc ion at the catalytic site of the enzyme. The introduction of an enantiometric dipeptide unit, D-Leu-D-Ala, to the P2-P1 subsites demonstrated an increased binding capacity to the extended S4-S1 subsites of collagenase, thus providing proteinase-resistant inhibitor.

[Studies on the synthesis of condensed pyridazine derivatives. II. Synthesis and anxiolytic activities of 2-aryl-4,4a,5,6-tetrahydropyridazino[4,3-c]quinolin-3(2H)-ones, 2-aryl-4a,5-dihydro-2H-(1)benzothiopyrano[4,3-c]pyridazin-3(4H)-ones, and related compounds]

A series of 2-aryl-4,4a,5,6-tetrahydropyridazino[4,3-c]quinolin-3(2H)- ones, 2-aryl-4a,5-dihydro-2H-(1)benzothiopyrano[4,3-c]pyridazin-3( 4H)-ones, and related compounds were synthesized and tested for their ability to displace [3H]diazepam from rat brain membranes in vitro, and to prevent bicuculline-induced convulsions in mice in vivo. Among them, 2-(4-chlorophenyl)-4a,5-dihydro-2H-(1)benzothiopyrano[4,3-c]pyr idazin-3(4H)- one (16b) showed remarkable activities both in vitro (Ki 48 nM) and in vivo (ED50 12.4 mg/kg, p.o.). The trans sulfoxide (19a) of 16b exhibited anxioselective pharmacological activities. Compound 19a was equipotent with diazepam in the anticonflict assay (Vogel type, rat, MED 10 mg/kg, p.o.) while exhibiting reduced muscle relaxation (rotarod test) and narcotic potentiation. The structure-activity relationships are discussed.