Mutation analysis of p53 gene in childhood malignant solid tumors

Alterations of the p53 gene have been extensively investigated in a wide variety of human malignancies. However, data on childhood malignant solid tumors are still limited. Mutations of the p53 gene on exons 5 through 8 were examined in 82 childhood malignant solid tumors by the polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method, and the nature of these mutations was confirmed by direct sequencing. The 82 tumors examined included neuroblastomas (n = 44), Wilms' tumors in = 13), hepatoblastomas (n = 11), rhabdomyosarcomas (n = 10), extraosseus Ewing sarcomas (n = 2), undifferentiated sarcoma of the liver (n = 1), and fibrosarcoma (n = 1). Two sarcoma samples were identified as having point mutations. One was a rhabdomyosarcoma with a missense mutation at codon 273, substituting histidine (His) for arginine (Arg). Another was an undifferentiated sarcoma of the liver with a missense mutation at codon 245, substituting serine (Ser) for glycine (Gly). No mutations were detected among neuroblastomas, Wilms' tumors, or hepatoblastomas. The two sarcomas with mutations were localized tumors. Both patients who had these tumors are disease free for 8 and 5 years after treatment, respectively. The overall incidence of p53 mutations was low (2.4%, 2 of 82). However, the incidence, when calculated for sarcomas, was higher at 14.3% (2 of 14). These data indicate that p53 mutations are generally uncommon in childhood malignant solid tumors examined. However, in some childhood sarcomas, p53 mutations appear to have a causative role in the development of these tumors.

Developmental gene expression of gastrin receptor in rat stomach

Gastrin, which is present in fetal plasma, may have important roles in the development of gastric mucosa, since it is not only a potent stimulator of gastric acid secretion but also a growth promoting factor. Gastrin regulates various cellular functions via its receptors on cell membrane. Therefore, in order to elucidate a role for gastrin in the development of gastrointestinal system during gestation, Northern blot analysis was performed. The results of the study suggested that gastrin receptor is mainly present on parietal cells. Furthermore, proton pump and gastrin receptor gene expressions in parietal cells were strongly stimulated by the administration of exogenous gastrin. In conclusion, gastrin may be involved in the developmental change of parietal cells through its receptors.

Developmental changes in distribution of the mucous gel layer in rat small intestine

The intraluminal mucous gel layer across the small intestine of rats aged 3 days, 1, 2, 4 and 6 weeks (n=10x5) was studied to investigate its postnatal development. Celloidin stabilisation of dried cryostat sections of small intestine, with the luminal contents, preserved the intraluminal mucous gel layer for staining by the periodic acid-Schiff reaction. Morphological differences in the mucous gel, between the villi of the small intestine, in rats of several postnatal ages were observed, most notably after the age of 2 weeks. The adhesive mucous gel layer, covering the intestinal epithelium in the small intestine, appears to undergo rapid development after weaning.

[Trial of a detachable Y-shaped tube with two valves for serial examinations of CT arterial portography and CT hepatic arteriography]

In five patients with hepatocellular carcinoma, CT arterial portography (CTAP) and CT hepatic arteriography (CTHA) were performed serially by using a newly developed detachable Y-shaped tube with two valves that could be attached to a conventional angiographic sheath. Two catheters could be inserted into the conventional angiographic sheath without blood backflow by using the Y-shaped tube. One catheter could be easily and safety placed on the common or proper hepatic artery, and the other on the superior mesenteric artery. This detachable Y-shaped tube with two valves could make it easy to perform serial CTAP and CTHA examinations.

Development of the human principal sensory trigeminal nucleus: a morphometric analysis

The anatomical development of the principal sensory trigeminal nucleus was assessed with morphometric features using serial celloidin sections of 15 human brains, including 12 brains obtained from fetuses and neonates. A microscope and an optical electronic planimeter combined with a computer were employed for morphometric measurements of columnar areas, neuronal numbers, neuronal areas and neuronal perimeters to statistically analyze and evaluate the development of neuronal densities, neuropil indexes and circularity ratios. We could not detect the principal sensory trigeminal nucleus in the specimen of 12 gestational weeks (GW). Microscopic observation disclosed that the fetal principal sensory trigeminal neurons approached those of the adult around 33 GW in terms of cell arrangements, amounts of Nissl bodies and morphology of neurons. Our morphometric analysis showed that the columnar volume, the neuronal area and the neuropil index increased with gestational age. The neuronal density decreased with gestational age, especially from 16 to 32 GW. Comparing the neuronal area with the columnar volume, it developed before the columnar volume during the fetal period. The neurons of the principal sensory trigeminal nucleus matured around 33 GW under microscopic observation and in terms of the distribution of neuronal areas. The development of the neuropil may accelerate after individual neurons of principal sensory trigeminal nucleus mature.

Development of the human lateral vestibular nucleus: a morphometric evaluation

The development of the human lateral vestibular nucleus was studied on serial sections of the brain of 8 fetuses and neonates at 12-40 weeks of gestation, an infant at 2 months of age and an adult of 63 years using a microscope with a drawing tube and an image-analysing computer system. A morphometric analysis revealed that the lateral vestibular nucleus, whose neurons were distinguished from glia after 16 weeks of gestation, divided cytoarchitectonically into the medial and the lateral subnuclei at 21 weeks of gestation onwards, and showed the moderate development in terms of the columnar length and volume, neuronal size and neuropil.

Expression of matrix metalloproteinases during rat skin wound healing: evidence that membrane type-1 matrix metalloproteinase is a stromal activator of pro-gelatinase A

Skin wound healing depends on cell migration and extracellular matrix remodeling. Both processes, which are necessary for reepithelization and restoration of the underlying connective tissue, are believed to involve the action of extracellular proteinases. We screened cDNA libraries and we found that six matrix metalloproteinase genes were highly expressed during rat skin wound healing. They were namely those of stromelysin 1, stromelysin 3, collagenase 3, gelatinase A (GelA), gelatinase B, and membrane type-1 matrix metalloproteinase (MT1-MMP). The expression kinetics of these MMP genes, the tissue distribution of their transcripts, the results of cotransfection experiments in COS-1 cells, and zymographic analyses performed using microdissected rat wound tissues support the possibility that during cutaneous wound healing pro-GelA and pro-gelatinase B are activated by MT1-MMP and stromelysin 1, respectively. Since MT1-MMP has been demonstrated to be a membrane-associated protein (Sato, H., T. Takino, Y. Okada, J. Cao, A. Shinagawa, E. Yamamoto, and M. Seiki. 1994. Nature (Lond.). 370: 61-65), our finding that GelA and MT1-MMP transcripts were expressed in stromal cells exhibiting a similar tissue distribution suggests that MT1-MMP activates pro-GelA at the stromal cell surface. This possibility is further supported by our observation that the processing of pro-GelA to its mature form correlated to the detection of MT1-MMP in cell membranes of rat fibroblasts expressing the MT1-MMP and GelA genes. These observations, together with the detection of high levels of the mature GelA form in the granulation tissue but not in the regenerating epidermis, suggest that MT1-MMP and GelA contribute to the restoration of connective tissue during rat skin wound healing.

Matrix metalloproteinases as stromal effectors of human carcinoma progression: therapeutic implications

The matrix metalloproteinases (MMPs) are extracellular zinc-enzymes implicated in a number of physiological and pathological tissue remodeling processes, including cancer progression. For a long time they have been thought to be produced by malignant cells and to specifically contribute to tumor invasion, through their ability to degrade extracellular matrix components. However, studies performed over the last few years have demonstrated that extracellular proteinases implicated in the progression of human carcinomas, including most MMPs, are in fact predominantly expressed by stromal and not by cancer cells. Furthermore, membrane receptors, activators and/or binding sites for some of these proteinases are also predominantly found to be associated with stromal cells. These findings, together with the observation that MMPs can cleave some molecules implicated in controlling growth factor activities, suggest that the role of MMPs during cancer progression is not limited to facilitating malignant cell invasion alone but is also likely to participate in other aspects of the malignant phenotype. MMPs should in fact be regarded as pan-regulators of tissue neoformation characteristic of malignant tumors, which includes both epithelial cell expansion and stroma formation. In this context, synthetic MMP inhibitors which are presently designed should lead to the development of a new generation of anticancer agents with additional beneficial properties compared to the existing cytotoxic agents used in the treatment of human malignancies.

Rat stromelysin 3: cDNA cloning from healing skin wound, activation by furin and expression in rat tissues

From a rat skin wound healing cDNA library, a clone encoding stromelysin 3 (ST3) was isolated. The predicted rat ST3 has 491 amino acids, and shows 83, 95 and 58% homology with human, mouse and Xenopus ST3, respectively. COS-1 cells transfected with this rat ST3 cDNA produced the ST3 proform, which could be converted to the mature ST3 form by co-transfection with rat furin cDNA. In addition to healing skin, the rat ST3 gene was found to be strongly expressed in normal adult uterus and ovary, and at lower levels in chemically-induced mammary tumors.

Beneficial effects of growth hormone combined with parenteral nutrition in the management of inflammatory bowel disease: an experimental study

BACKGROUND

Growth hormone (GH) improves net protein anabolism and stimulates wound healing. Although GH is also known to exert the trophic effect on the intestinal tract, its role in the healing of intestinal ulceration is not known. The aim of this study was to evaluate the effects of exogenous GH coinfused with parenteral nutrition (PN) in an experimental model of inflammatory bowel disease in rats.

METHODS

All rats underwent central venous cannulation and were randomized to two groups after induction of small intestinal ulceration with indomethacin. Both groups received the same PN formula. In addition, the GH group (n = 10) received subcutaneous injections of human GH at a dose of 1.0 IU/kg daily for 4 days, whereas the control group (n = 10) received injections of normal saline solution. Nitrogen balance, macroscopic inflammation score, intestinal myeloperoxidase activity, DNA content, and mucosal permeability were determined for each rat. Insulin-like growth factor-I (IGF-I) mRNA was detected by reverse transcription and polymerase chain reaction.

RESULTS

Administration of GH significantly improved the cumulative nitrogen balance, ameliorated the gross inflammation score, and decreased intestinal myeloperoxidase activity. Similarly, intestinal permeability was significantly decreased in the GH group as compared with the control group. GH treatment resulted in increased plasma concentration of IGF-I and IGF-I mRNA expressions in both the liver and the small intestine compared with those in the control group.

CONCLUSIONS

Exogenous GH plays an important role in accelerating intestinal healing in an experimental model of small bowel ulceration in rats. The mechanisms may include the stimulated IGF-I production, which thereafter augments intestinal epithelial cell growth.

Nitric oxide inhalation therapy for an infant with persistent pulmonary hypertension caused by misalignment of pulmonary veins with alveolar capillary dysplasia

Misalignment of pulmonary veins with alveolar capillary dysplasia (MPV) has been reported to be a rare cause of persistent pulmonary hypertension of the newborn (PPHN) and to be fatal despite extracorporeal membrane oxygenation (ECMO). A full-term female neonate with PPHN was brought to the hospital for ECMO therapy at 2 days of age. On the 14th day of life, she was extubated early after the second run of ECMO, and underwent nitric oxide (NO) inhalation therapy in the incubator. She died of catheter-related sepsis on the 61st day of life. After autopsy findings revealed MPV, the longest survival with this disease was documented. NO inhalation therapy in the incubator may provide time for lung transplantation.

Hyaluronic acid of wound fluid in adult and fetal rabbits

Fetal wound healing proceeds without fibrosis or scar formation in contrast to adult wound healing. The mechanisms responsible for this remarkable process are mediated in part through a fetal wound extracellular matrix rich in hyaluronic acid (HA). Polyvinylalcohol sponge (PVA) wound implants were placed pervertebrally at 24 days' gestation in fetal (N = 118) rabbits and in adult (N = 44) rabbits, and then harvested at 1, 2, 3, 4, 5, and 7 days postwounding. To analyze the fetal and adult wound matrix, the HA concentration of wound fluid within the PVA sponge was quantitated using a newly developed assay. A significantly increased (P < .05) HA deposition on days 1 through 7 in the fetal wounds was found compared with the adult wound. These observations may suggest an important physiologic role in fetal wound healing by providing a more fluid and malleable matrix. These results, coupled with earlier findings of the lack of an acute inflammatory response in the fetus, further support the hypothesis that fetal response to injury is significantly different from adult response in this prescience of an implanted PVA sponge.

Total parenteral nutrition increases uptake of latex beads by Peyer's patches

BACKGROUND

Dysfunction of the intestinal barrier, as evidenced by increased intestinal permeability and bacterial translocation, has been reported under total parenteral nutrition (TPN). However, the role of Peyer's patches on the intestinal barrier in TPN is not well understood. We investigated whether TPN alters the uptake of microparticles by the follicle-associated epithelium of Peyer's patches.

METHODS

Twenty rats were divided into two groups, a control group and a TPN group. Fluorescent polystyrene latex beads, 3.2 +/- 0.2 microns in diameter, were used as a probe for measuring the uptake by Peyer's patches. After 1 week of consuming either the control or TPN diet, rats were killed. On the day of killing, 0.1 mL of latex beads solution was injected into a 1-cm length of ileal loop, within 10 cm of the ileocecal valve. Samples were taken after 30 minutes of injection, sectioned by cryostat, and then viewed under a fluorescent microscope. Follicle-associated epithelial length and particles were counted using a confocal laser scanning microscope. The number of particles within each compartment was standardized per unit length of epithelium of Peyer's patches.

RESULTS

Particle numbers within Peyer's patch dome of the TPN group were significantly increased compared with those of the control group (p < .01).

CONCLUSIONS

These data suggest that dysfunction of the intestinal barrier in TPN might be associated with a change of uptake by Peyer's patches.

Experience in tracheobronchial reconstruction with a costal cartilage graft for congenital tracheal stenosis

Although successful surgical management of congenital tracheal stenosis has been reported, it is still controversial as to the best operative procedure. Eleven infants with congenital tracheal stenosis were evaluated to confirm the efficacy of tracheobronchial reconstruction with costal cartilage graft. Symptoms ranged from recurrent respiratory infection to severe respiratory failure. All infants had other congenital anomalies in addition to tracheal stenosis. Notably, five infants had pulmonary artery sling and four infants had patent ductus arteriosus. Definitive diagnosis was made by bronchoscopy, results of which showed complete tracheal rings in all patients with severely compromised tracheobronchial lumens. Five infants had elongated stenosis involving nearly the whole length of the trachea, and five infants had segmental stenosis involving nearly one half the length of the trachea. One infant had bilateral stenosis of the main bronchi. Early experience included two deaths from problems related to the repair. The involvement of the carina and the distal portion of the trachea was associated with increased complications and a higher mortality rate. Currently, our preferred technique facilitated by extracorporeal membrane oxygenation (ECMO) includes carinal reconstruction with a thin-wall intraluminal stent. Bronchoscopy is essential for accurate intraoperative incision of the trachea, post-operative airway management for several weeks, and removal of the intraluminal stent.

Developmental changes in distribution of the mucous gel layer and intestinal permeability in rat small intestine

BACKGROUND

From the developmental aspects, the distribution of fluorescein isothiocyanate dextran 70,000 (FTTC-dextran) and mucous gel across the lumen of small intestine was observed as an investigation into the role of mucous gel on intestinal permeability. Furthermore, the effect of N-acetyl cysteine (NAC), a mucolytic agent, on intestinal permeability was examined.

METHODS

In suckling and weaned rats, FTTC-dextran (750 mg/kg body wt) was gavage-fed. After 3 hours, blood samples were taken by cardiac puncture to analyze plasma FTTC-dextran by fluorescence spectrometry. Samples of small intestine with luminal contents were frozen and sectioned in a cryostat for fluorescence microscopy; the same sections were placed in a 0.2% celloidin solution to preserve mucous gel and were stained by periodic acid-Schiff reaction for light microscopy. In weaned rats, intestinal permeability was examined with different concentrations of intraluminally instilled NAC.

RESULTS

The plasma level of FTTC-dextran showed a significant increase (p < .01) in suckling rats compared with the weaned rats. Morphologic findings were similar in both the jejunum and ileum: The spaces between villi were not entirely filled with mucus but filled with FTTC-dextran in suckling rats, whereas the spaces were filled with mucus and not filled with FTTC-dextran in weaned rats. Intestinal permeability in groups with NAC were significantly higher (p < .01) than that in group without NAC.

CONCLUSIONS

These results suggest that an increase in the mucous gel layer that coats the epithelial lining according to the maturation of the gastrointestinal tract is one of the most important factors for a restriction in intestinal permeability.

Involvement of beta-adrenergic receptor kinase-1 in homologous desensitization of histamine H2 receptors in human gastric carcinoma cell line MKN-45

The poorly differentiated human gastric carcinoma cell line MKN-45 possesses histamine H2 receptors which are homologously desensitized by histamine. In order to clone the cDNA of a receptor kinase specific for H2 receptors, we performed RT-PCR at a low annealing temperature using oligo-DNA primers bearing the conserved sequences of the kinase domain of the G protein-coupled receptor kinase (GRK) family. However, we were able to isolate only cDNAs for beta-adrenergic receptor kinase 1 (beta ARK1) and GRK6. Interestingly, treatment of MKN-45 cells with beta ARK1 antisense phosphorothioate oligo-DNA (PON) resulted in significant loss of desensitization of H2 receptors by histamine, whereas GRK6 antisense PON had no effect. Thus, beta ARK1 appears to be involved in the homologous desensitization of H2 receptors in MKN-45 cells.

Prenatal diagnosis of congenital diaphragmatic hernia and pulmonary hypoplasia and therapeutic strategy

The outcome of fetuses with congenital diaphragmatic hernia (CDH) has been reported to be fatal when pulmonary hypoplasia (PH) is severe. As an indicator of PH, we attempted to measure the lung-thorax transverse area ratio (L/T) using ultrasonic echography. Immediate postnatal surgery was performed using high-frequency oscillatory ventilation (HFOV) and sometimes followed by extracorporeal membrane oxygenation (ECMO). Eighteen fetuses were treated and 14 survived. L/T correlated well with the best preductal arterial blood gas data before surgical reduction during manual ventilation and HFOV, while preductal PO2 and alveolar-arterial oxygen differences from patients managed with HFOV were better than those in patients with manual ventilation. Although L/T also correlated with the duration of O2 therapy and hospitalization in survivors without major anomalies, there was no significant difference between L/T in survivors and nonsurvivors. Because delayed institution of ECMO and complications related to ECMO management seemed to be a major cause of death in non-survivors, the unsalvageable L/T due to PH was estimated to be below 0.06 for HFOV and below 0.1 for conventional ventilation based on the correlation between L/T and preductal P02. These results suggest that L/T is a useful indicator of PH in patients with CDH and also that HFOV is advantageous in treating CDH with PH. The advantage of prenatal diagnosis in predicting unsalvageable L/Ts, should be considered in the therapeutic strategy.

An imprinted gene p57KIP2 is mutated in Beckwith-Wiedemann syndrome

p57KIP2 is a potent tight-binding inhibitor of several G1 cyclin/Cdk complexes, and is a negative regulator of cell proliferation. The gene encoding p57KIP2 is located at 11p15.5 (ref. 2), a region implicated in both sporadic cancers and Beckwith-Wiedemann syndrome, a cancer-predisposing syndrome, making it a tumour-suppressor candidate. Several types of childhood tumours including Wilms' tumour, adrenocortical carcinoma and rhabdomyosarcoma exhibit a specific loss of maternal 11p15 alleles, suggesting that genomic imprinting is involved. Genetic analysis of the Beckwith-Wiedemann syndrome indicated maternal carriers, as well as suggesting a role of genomic imprinting. Previously, we and others demonstrated that p57KIP2 is imprinted and that only the maternal allele is expressed in both mice and humans. Here we describe p57KIP2 mutations in patients with Beckwith-Wiedemann syndrome. Among nine patients we examined, two were heterozygous for different mutations in this gene-a missense mutation in the Cdk inhibitory domain resulting in loss of most of the protein, and a frameshift resulting in disruption of the QT domain. The missense mutation was transmitted from the patient's carrier mother, indicating that the expressed maternal allele was mutant and that the repressed paternal allele was normal. Consequently, little or no active p57KIP2 should exist and this probably causes the overgrowth in this BWS patient.