A solitary congenital self-healing histiocytosis. Report of a case and review of the literature

Congenital self-healing histiocytosis (CSHH), and especially the solitary variant, is a rare primary skin disorder. We report on a newborn with a congenital solitary ulcerated skin nodule. Extracutaneous involvement was not found. A skin biopsy was performed at the age of 44 days and revealed a dense dermal infiltrate of large histiocytic cells. Immunohistochemical study revealed that the cells of the dermal infiltrate were Langerhans' cells which were strongly positive for S- 100 and negative for lysozyme, leukocyte common antigen and alpha-1-antichymotrypsin. The skin lesion involuted spontaneously over the next month without any treatment. The clinical, histopathological and immunohistochemical results fulfilled the criteria of solitary CSHH. We herein report the first case of CSHH in Taiwan and the twelfth case of solitary CSHH in the world.

Murine interleukin-11 (IL-11) is expressed at high levels in the hippocampus and expression is developmentally regulated in the testis

IL-11, derived from a bone marrow stromal cell line, has pleiotropic effects on both hematopoietic cells and nonhematopoietic cells. However, no previous studies have systematically addressed expression of IL-11 in primary tissues in vivo and the relationship of IL-11 tissue specific gene expression and function of IL-11 is not clear. In the present study, we examined constitutive IL-11 expression in various murine adult tissues in vivo. IL-11 mRNA is expressed in a wide range of normal tissues (including hematopoietic organs) at levels only detected by RT-PCR. IL-11 protein was detected in brain and testis by Western blot analysis. The in vivo cellular distribution of IL-11 expression was examined by in situ hybridization. In brain, IL-11 message is distributed in granular layer dentate gyrus and pyramidal cell layers of hippocampus. IL-11 is also expressed in anterior horn cells and lateral column neuronal cells of the spinal cord. In testis, IL-11 mRNA is expressed in round spermatids at stage VI-IX seminiferous tubules. IL-11 expression in testis is restricted to developing spermatogonia and is developmentally regulated, since no expression is seen in mice genetically deficient in germ cells and in mice prior to sexual maturation. These expression data correlate with functional data demonstrating that IL-11 stimulates proliferation in vitro of a hippocampus neuronal progenitor cell line and administration of IL-11 in vivo accelerates recovery of spermatogenesis after cytotoxic therapy. These studies suggest that IL-11 may be an important regulator in neural and testicular function.

Alterations of the thymic selection process in transgenic mice expressing SV40 large T antigen

We generated SV40 T antigen transgenic mice (lines SVT125, SVT127, and SVT248) which developed unique thymic carcinomas originating from thymic cortical epithelial cells. In these mice we observed alterations in the thymic selection process not reported before in SV40 T antigen transgenic mice. Along with tumor cell growth, thymocytes increased in number and the proportion of CD4 or CD8 single positive cells rose to 10 times the normal level. Expression of SV40 T antigen was detectable by Northern analysis in thymic stromal cells but not in thymocytes. Thymic stromal cell lines, derived from the thymic tumor, produced high levels of cytokines which caused morphological transformation and growth stimulation in hematopoietic stem cells, including fetal liver cells and bone marrow cells. These observations suggest that the unusual multiplication of thymocytes and the alterations in thymic selection are the result of the activity of thymic stromal cells transformed by SV40 T antigen. The cell lines derived from the tumor can thus be used to study cytokines involved in thymic differentiation of T cells.

BRCA1 is a 220-kDa nuclear phosphoprotein that is expressed and phosphorylated in a cell cycle-dependent manner

Mouse polyclonal antibodies, raised against three regions of the human BRCA1 protein, were characterized and revealed BRCA1 as a 220-kDa nuclear phosphoprotein in normal cells. All three antisera recognize both in vitro-translated and recombinant, baculovirus-derived BRCA1, which co-migrate with BRCA1 from the human breast epithelia cell line, HBL100. BRCA1 expression and phosphorylation are shown to be cell cycle dependent, with greatest expression and phosphorylation occurring in S and M phases. Cyclin-dependent kinase 2 and other kinases associated with cyclins D and A are shown to bind to and phosphorylate BRCA1, suggesting that the biological activity of BRCA1 may be regulated by cyclin-dependent kinases.

Inactivation of the mouse Brca1 gene leads to failure in the morphogenesis of the egg cylinder in early postimplantation development

BRCA1 is proposed to be a tumor suppressor gene. To explore the biological function of BRCA1, a partial deletion (amino acids 300-361) of mouse Brca1 exon 11 was introduced into the genome of embryonic stem (ES) cells by homologous recombination. Mice carrying one mutated allele of Brca1 appear normal and are fertile up to 10 months of age without any sign of illness. However, no viable progeny homozygous for the Brca1 mutant allele were obtained. Detailed analysis of large numbers of embryos at different stages of development indicated that the homozygous mutant concepti are severely retarded in growth as early as embryonic day 4.5 (E4.5) and are resorbed completely by E8.5. Although the homozygotes at E5.5-E6.5 are able to synthesize DNA and display distinguishable embryonic and extraembryonic structures, they fail to differentiate and form egg cylinders. Consequently, they were unable to form primitive streaks and undergo gastrulation. Consistent with these in vivo results, blastocysts homozygous for mutated Brca1 alleles are at a considerable disadvantage when grown in vitro. These observations suggest that Brca1 has an important role in the early development of mouse embryos.

Effects of circulating IGF-I on glucose and amino acid kinetics in the ovine fetus

To investigate the role of insulin-like growth factor I (IGF-I) in the regulation of fetal metabolism, the kinetics of leucine, phenylalanine, and glucose were assessed in the chronically catheterized ovine fetus (0.85 gestation) before and during infusion of recombinant human IGF-I (rhIGF-I). Substrate kinetics were determined by tracer dilution. rhIGF-I was infused at 6.7 nmol.kg fetus-1.h-1. Fetal insulin and growth hormone concentrations were significantly decreased by 50% during rhIGF-I infusion. Net umbilical glucose uptake was unchanged, and glucose rate of appearance increased in the fed state only. There were no changes in the net umbilical uptakes of leucine or phenylalanine, but the rates of appearance of both declined during rhIGF-I infusion, indicative of decreased fetal protein breakdown (Ra,Leu 45.4 +/- 1.40 to 40 +/- 1.4 mumol/min in the fed state, 43 +/- 1.5 to 37 +/- 1.5 mumol/min in the fasted state; Ra,Phe 10.7 +/- 0.3 to 10.4 +/- 0.3 mumol/min in the fed state and from 10.7 +/- 0.3 to 9.8 +/- 0.3 mumol/min in the fasted state). Leucine oxidation was also decreased (8.90 +/- 0.76 to 6.52 +/- 0.81 mumol/min, P = 0.025), more so in the fasted than the fed state. These results indicate a significant antiproteolytic endocrine effect for IGF-I in the late-gestation mammalian fetus.

Differential expression of insulin-like growth factor binding proteins in murine hematopoietic stromal cell lines

The expression of the insulin-like growth factor (IGF) system in the hematopoietic microenvironment during ontogeny was studied utilizing immortalized murine cell lines established from several sites of hematopoiesis. Conditioned media was obtained from tissue cultures of murine yolk sac endoderm and mesoderm, fetal liver and adult bone marrow stromal cell lines. IGF-I and -II were quantified by radioimmunoassay and RT-PCR. The presence of insulin-like growth factor binding proteins (IGFBPs) in conditioned media was determined by Western ligand blot and Western immunoblot. IGF-I and IGF-II were present in conditioned media from every stromal cell line and differential expression of the IGFBPs was found among the hematopoietic sites. Stimulation of the cell lines with interleukin-1 alpha altered the IGFBPs in yolk sac endoderm and bone marrow conditioned media. We report that IGF-I and -II are expressed in stromal cell lines obtained from different ontogenic sites of hematopoiesis and IGFBPs are differentially expressed by these sites. The expression of IGFBPs, but not IGFs, is in part regulated by interleukin-1 alpha.

The molecular basis of E2F-1/DP-1-induced S-phase entry and apoptosis

The transcription factor E2F plays a critical role in the G1 to S transition. E2F is a heterodimer formed by members of the E2F and DP families of DNA-binding proteins. Ectopic expression of E2F-1, the first member of the E2F family identified, is sufficient to cause quiescent cells to enter S phase. Thus, the biological significance of the interaction of E2F-1 with its DP protein partner, DP-1, was unclear. Here, we report on the role of DP-1 in the mediation of E2F-induced S-phase entry and apoptosis. Cells inducible for DP-1, E2F-1, or both were established and characterized. Ectopic expression of DP-1 alone fails to promote cell cycle entry, even when the potent transactivation domain of human papillomavirus-VP16 is fused to the DNA-binding domain of DP-1. In contrast, coexpression of DP-1 and E2F-1 results in greater loss of G1 regulation and significantly more apoptosis than does E2F-1 alone. Using clones co-inducible for DP-1 and E2F-1, expression of potential target genes of E2F activity that may account for its ability to induce S-phase entry was also examined. Induction of E2F-1/DP-1 resulted in increased expression and activity of cyclins A and E, as well as CDK2, prior to S-phase entry. Cyclin D and CDK4, however, were not induced. Phosphorylation of the retinoblastoma protein is also increased following induction of E2F-1/DP-1, suggesting that E2F can feed-back on the retinoblastoma protein, presumably through activation of cyclin A- and/or E-associated kinase activity.

Panencephalitic Creutzfeldt-Jakob disease. Unusual presentation of magnetic resonance imaging and proton magnetic resonance spectroscopy

We present serial magnetic resonance imaging (MRI) scans on a biopsy-verified case of Creutzfeldt-Jakob disease (CJD). The initial MRI scan demonstrated increased T2 signal-intensity within the basal ganglia and thalami. Subsequent MRI scans demonstrated a thin cortex, increased T2 signals diffusely within the white matter including U-fibers, and hypointense T2 signals within the basal ganglia, and thalami. Proton magnetic resonance spectroscopy (1H-MRS) study showed an absence of creatine, choline and N-acetylaspartate signals. By these characteristic findings, serial MRI and MRS studies may be helpful in differentiating CJD from other dementing illnesses.

Comparison of three typing methods for Pseudomonas aeruginosa

Fifty-seven independent isolates of Pseudomonas aeruginosa from blood specimens were typed with 3 different methods: ribotyping, random amplified polymorphic DNA (RAPD) typing, and pyocin typing. Ribotyping was performed by probing the rRNA genes of genomic DNA that was digested separately with 4 different restriction enzymes. Digestion of DNA from 57 P. aeruginosa isolates with BamHI, ClaI, EcoRI, and PstI produced 4, 4, 6, and 7 patterns, respectively. As a result, ribotyping classified the 57 isolates into 22 types. Six new ribotypes that had not been described previously were found. One BamHI, 1 ClaI, 2 EcoRI, and 2 PstI patterns were novel. RAPD typing was performed with two different polymerase chain reaction (PCR) primers (RAPD1 and RAPD2). Both primers classified the 57 isolates into 15 RAPD types and produced identical patterns. The pyocin typing method classified the 57 isolates into 10 types. According to the results obtained in this study, the ribotyping has a discriminatory index of 0.865, RAPD, 0.785, and pyocin typing, 0.676, respectively. The ribotyping method was the most effective among the 3 methods compared for typing P. aeruginosa isolates.

Molecular cloning and developmental expression of mouse p130, a member of the retinoblastoma gene family

With sequence homology to the SV40 T antigen-binding domain of the retinoblastoma protein (Rb), p107 and p130 constitute two additional members of the Rb family. To explore the potential function of p130 in mouse development, we cloned the full-length mouse cDNA for p130 and characterized p130 mRNA expression in mice. The deduced mouse p130 protein sequence shares a higher degree of similarity with mouse p107 than with mouse Rb. In adult mice, p130 mRNA is found in all tissues examined. Levels of p130 mRNA vary among different adult tissues, with the highest level in testis. Within testis, p130 mRNA is found predominantly in Leydig cells. Additionally, p130 expression in testis correlates with sexual maturation, suggesting p130 is important for the development of testis and, in particular, Leydig cells. In situ hybridization shows that in post coitus day 12.5 and 14.5 mouse embryos, distribution of p130 mRNA is quite uniform with the exception of a few tissues. Little differences in mRNA levels of either p130 or p107 were found between normal and Rb-deficient embryos, suggesting that p130 and p107 are expressed independently of Rb. Our data are consistent with the hypothesis that p130 and p107 do not compensate for the loss of Rb and support the view that p130 is related to, yet distinct from, the RB gene.

Monomeric immunoglobulin A protects glomerulus against polymeric immunoglobulin A immune complex in experimental immunoglobulin A nephropathy

Polymeric (p) IgA constitutes 13% of total serum IgA, whereas monomeric (m) IgA represents the other 87%. pIgA tends to form complexes in the circulation that eventually localize in the glomerulus. mIgA is a nonprecipitable antibody. When complexed with an antigen in vivo, the circulating mIgA immune complex (IC) thus formed does not deposit in the glomerulus. The purpose of the present study was to evaluate the influence of mIgA on the formation of pIgA-lC and subsequent glomerular deposition of the IC in an experimental model of IgA nephropathy. The influence of mIgA anti-dinitrophenyl (DNP) on pIgA anti-DNP/DNP-conjugated BSA (BSA-DNP) IC formation was assessed by double diffusion test and competition PAGE in combination with autoradiography. Only the BSA-DNP, a model antigen of relatively low molecular mass, was radiolabeled and monitored throughout the latter experiment. An analysis of clearance kinetics (1 and 6 hours) of the antigen using 4-week-old female BALB/c mice, and a series of renal studies were performed after intravenous injection with a single dose of combined pIgA anti-DNP, BSA-DNP, and mIgA anti-DNP. As demonstrated by the double diffusion test, addition of mIgA anti-DNP resulted in suppression of the precipitating reaction of pIgA anti-DNP and BSA-DNP. This effect was confirmed by PAGE for size determination of the BSA-DNP which had been complexed with either pIgA anti-DNP or a mixture of pIgA anti-DNP and mIgA anti-DNP. The clearance kinetics studies showed that the elimination of BSA-DNP injected with pIgA anti-DNP was prolonged in the presence of mIgA anti-DNP in a partially dose-dependent manner. The experimental mice receiving pIgA anti-DNP, BSA-DNP, and mIgA anti-DNP showed less hematuria (p < 0.005) than mice receiving pIgA anti-DNP and BSA-DNP (positive control) when examined 1 hour after injection. Immunofluorescence study of the renal tissue of mice receiving pIgA anti-DNP, BSA-DNP, and mIgA anti-DNP showed a suppressed glomerular localization of IgA and third component of complement, as compared with those injected with pIgA anti-DNP and BSA-DNP alone. Similarly, a significant decrease of glomerular BSA-DNP deposits was observed in mice receiving pIgA anti-DNP, BSA-DNP, and mIgA anti-DNP compared with those receiving pIgA anti-DNP and BSA-DNP alone, as demonstrated by light microscopic autoradiography. These findings indicate that a high dose of specific mIgA was capable of modulating glomerular deposition of the pIgA-IC in this animal model of IgAN.

Down regulation of bcl-2 by p53 in nasopharyngeal carcinoma and lack of detection of its specific t(14;18) chromosomal translocation in fixed tissues

High levels of bcl-2 protein have been found in a wide variety of human cancers. Since p53 gene inactivation occurs in over half of human cancers, it is possible that loss of p53-mediated repression of bcl-2 gene expression accounts, at least in part, for the frequent abnormalities in bcl-2 protein production seen in tumours. By using immunohistochemical methods, we have analysed thirty-three nasopharyngeal carcinomas for p53 and bcl-2 expression. We found an inverse correlation between the expression of these two proteins (P < 0.001). Moreover, we utilized universal oligonucleotide primers of a region 5' to the bcl-2 MBR and at the 3' end of JH segments to initiate a DNA polymerase chain reaction that amplified these bcl-2-JH junctures. Of the twelve nasopharyngeal carcinomas expressing bcl-2, none showed a t(14;18) chromosome translocation. These findings may indicate potential mechanisms by which bcl-2 regulates apoptosis.

The CD4/CD8 ratio in the blood does not reflect the response of this index in secondary lymphoid organs of weanling mice in models of protein-energy malnutrition known to depress thymus-dependent immunity

A low ratio of cellular numbers within CD4+ (helper/inducer) relative to CD8+ (suppressor/cytotoxic) thymic lymphocyte subsets (low CD4/CD8 ratio) is widely accepted as fundamental to the depression in thymus-dependent immunocompetence associated with wasting protein-energy malnutrition (PEM). The objective of this investigation, therefore was to determine the CD4/CD8 ratio in peripheral lymphoid compartments of diverse murine models of protein-energy malnutrition which produce systemic wasting (loss of approximately 1.8% of initial body weight per day), lymphoid involution and (as shown in many previous studies) depression in thymus-dependent immunocompetence. In the first of two experiments, male and female weanling mice of disparate inbred strains, CBA/J and C57BL/6J, were allocated to a zero-time control group (23- and 19-d-old, respectively), or to groups fed for 14 d as follows: ad libitum intake of a complete purified diet (19% crude protein, 17 kJ/g gross energy), restricted intake of the complete diet, or ad libitum intake of an isocaloric low protein diet (0.6% crude protein). In a supplementary experiment, (0.6% crude protein). In a supplementary experiment, male and female C57BL/6J weanling mice were fed the complete diet or the low protein diet for either 6 or 21 d. CD4+ and CD8+ thymic lymphocytes were enumerated by flow cytometry in mononuclear cell suspensions from blood, spleen and mesenteric lymph nodes. A low CD4/CD8 ratio is common in the blood in wasting protein-energy malnutrition, but appears uncharacteristic of the profoundly involuted lymphoid organs which generate acquired immune responses. The CD4/CD8 ratio is irrelevant to the thymus-dependent immunoincompetence previously demonstrated in the rodent models used in this investigation.

Amelioration of the behavioral phenotype in genetically ataxic mice through bilateral intracerebellar grafting of fetal Purkinje cells

We have previously applied neural grafting to "Purkinje cell degeneration" mutant mice (gene symbol pcd, mouse chromosome 13), a model of recessively inherited cerebello-olivary atrophy, to create appropriate interactions between wild-type and mutant cells in elucidating gene effects on the involved neuron populations and to address issues of the structural integration of donor Purkinje cells into the disrupted cerebellar loop. Behaviorally, pcd homozygotes manifest ataxic signs beginning at 3-4 wk of age. The functional effects of cerebellar transplants on motor performance have long remained an open question. The aim of the present study was to determine the recovery of motor responses in pcd mutants in a battery of behavioral tasks after bilateral transplantation of cerebellar cell suspensions (prepared from wild-type mice) into the parenchyma of the deep cerebellar nuclei of the hosts, according to a protocol that emphasizes the reconstruction of the missing inhibitory cortico-nuclear projection. With this approach, the denervated deep nuclei of the host receive a new Purkinje axonal innervation; further, most transplanted Purkinje cells end up occupying cortical localities anyway and display a correct dendritic tree orientation toward the pia. Motor coordination and fatigue resistance were assessed in a rotarod treadmill apparatus, a behavioral paradigm useful in studying various brain abiotrophies and treatments, including developmental perturbations of the cerebellar cytoarchitecture. Locomotor activity was quantified by the number of squares mice crossed as they moved about in an open-field matrix. Grafted pcd mice performed significantly better than sham-operated mutants in both of these tasks. Moreover, graft-recipient mice were able to sustain their abdomen above the floor on their limbs during movement, contrasting to the typical lowered, widened stance of sham-operated pcd mutants. These findings clearly demonstrate that bilateral transplants of fetal Purkinje cells have functional effects on motor performance in the pcd model of hereditary cerebellar ataxia.

Soluble CD44 isoforms in serum as potential markers of metastatic gastric carcinoma

A splice variant of CD44 (exon V4-V7) confers metastatic behavior in a rat carcinoma model; aberrant expression of splice variants has been detected on a variety of human tumor cell lines as well as primary and metastatic human tumors, including lymphomas, carcinomas (colon, thyroid, mamma, bladder), and glioma. We used enzyme-linked immunosorbent assay to determine the concentration of soluble CD44 in the serum samples of 10 normal individuals and 41 patients with various stages of gastric cancer. Soluble CD44S and its isoforms, V5 and V6, were present in the serum of normal individuals (288.53 +/- 18.33, 25.49 +/- 1.70, and 148.32 +/- 3.15 ng/ml, respectively). The concentrations of soluble CD44 V5 and V6 were elevated in patients with advanced gastric carcinoma (69.39 +/- 6.06 and 216.62 +/- 32.98 ng/ml, respectively). Serum CD44 V5 concentrations correlated with the extent of tumor invasion (T), the status of lymph node involvement (N), and distant metastasis (M) (TNM staging) (p < 0.05), whereas CD44S did not. These results suggest that detection of abnormal regulation of CD44 splicing could be helpful in gastric cancer diagnosis and disease evaluation.

Insulin-like growth factors I and II peptide and messenger RNA levels in macrosomic infants of diabetic pregnancies

OBJECTIVE

Fetal macrosomia is a common complication of maternal diabetes mellitus and is associated with substantial morbidity, but the precise cellular and molecular mechanisms that induce fetal macrosomia are not well understood. We hypothesized that the macrosomia or accelerated fetal growth seen in infants of diabetic mothers is due to a perturbation of a putative placental-fetal growth axis involving growth hormone and insulin-like growth factors. Insulin-like growth factors I and II (IGF-I and IGF-II) are ubiquitous peptides that share structural homology with insulin and have been implicated in processes that control fetal growth. Studies of IGF levels in pregnancies complicated by diabetes and macrosomia have shown conflicting results. We set out to resolve these inconsistencies using molecular techniques to measure the placental IGF-I and IGF-II messenger RNA levels in placentas and a specific radioimmunoassay to measure IGF-I and IGF-II peptide levels in cord serum of normal and diabetic pregnancies.

METHODS

Placentas and cord blood were collected immediately after delivery at term from patients from each of three study groups: 1) nonmacrosomic infants of nondiabetic mothers (controls), 2) macrosomic infants of diabetic mothers, and 3) nonmacrosomic infants of diabetic mothers. Both IGF-I and IGF-II levels were measured in cord serum and placental tissue by a specific radioimmunoassay. Total RNA was extracted and analyzed by Northern gels hybridized to IGF-I or IGF-II riboprobes.

RESULTS

Levels of IGF-I in cord serum from the macrosomic diabetic group (83 +/- 4.2 ng/mL) were significantly higher than levels from either the nonmacrosomic nondiabetic group (38 +/- 1.9 ng/mL) or the nonmacrosomic diabetic group (13 +/- 3.5 ng/mL). There was a direct linear correlation between cord serum IGF-I and infant birth weight, independent of diabetes (r2 = 0.61, P < .01). On the other hand, IGF-II cord serum levels were elevated in diabetic pregnancies (337 +/- 12.2 ng/mL) compared with nondiabetic women (172 +/- 19.8 ng/mL), but there was no correlation with birth weight (r2 = 0.035, P = .52). In contrast to cord blood levels, IGF-II peptide levels were significantly decreased in the placentas from mothers with diabetes compared with nondiabetic controls (116 +/- 3.2 versus 158 +/- 5.3 ng/mL, respectively). Levels of IGF-I peptide in placentas from both nondiabetic controls and diabetic mothers were below the sensitivity of the assay. Levels of IGF-I and IGF-II mRNA did not differ in placentas from diabetic mothers versus nondiabetic controls.

CONCLUSION

Cord serum IGF-II levels are elevated in diabetic pregnancies without a concomitant increase in placental IGF-II levels. This novel finding, combined with the finding that IGF-I levels are correlated with macrosomia independent of the diabetic state, contributes to our understanding of the possible mechanisms involved in fetal growth in pregnancies complicated by diabetes.

Bilateral tubo-ovarian actinomycosis in the presence of an intrauterine device: a case report

An uncommon case of actinomycosis found in bilateral tubo-ovarian abscess is presented. Preoperatively, bilateral ovarian tumors were initially suspected by pelvic examination and ultrasonography. The patient received total abdominal hysterectomy and bilateral salpingo-oophorectomy. The initial pathology frozen section report showed abscess without evidence of malignancy. The final pathological finding revealed actinomycosis in bilateral tubo-ovarian abscess. In addition, an intrauterine contraceptive device, Copper-T, was found in the uterine cavity. The radiologic findings, gross pathological feature, histopathological pictures and treatment of pelvic actinomycosis are discussed, with review of the literature in English.

Coordinate IGF-I and IGFBP5 gene expression in perinatal rat brain after hypoxia-ischemia

Insulin-like growth factor I (IGF-I) is an anabolic pleiotrophic factor essential for postnatal rat brain development, especially during the first 21 days, the "critical growth period." Cerebral hypoxic-ischemic insults occurring during the perinatal period can result in neuronal necrosis and permanent brain damage. To understand the regulation of the action of IGF-I in response to such a metabolic insult, we investigated the gene expression of IGF-I, type I IGF receptor, IGF binding protein (IGFBP)2, and IGFBP5 during the first 72 h after hypoxia-ischemia in the immature rat. At 1 h of recovery, messenger RNA (mRNA) levels of all IGF system components were decreased throughout the hemisphere ipsilateral to the carotid artery ligation. This decrease is more pronounced at 24 h of recovery, especially in areas vulnerable to hypoxic-ischemic injury, such as the thalamus and hippocampus. At 72 h of recovery, although IGFBP2 and type 1 IGF receptor mRNA levels remain suppressed, gene expression of both IGF-I and IGFBP5 was activated in reactive astrocytes.Therefore, during the critical growth period in rats, the transcriptional levels of all IGF system components are extremely sensitive to metabolic perturbations associated with cerebral hypoxia-ischemia. The immediate decrease in IGF-I gene expression may be partially responsible for the impending neuronal death and selective vulnerability of myelinogenesis during the perinatal period.

Refolding, purification, and characterization of human erythropoietin binding protein produced in Escherichia coli

The extracellular domain of the human erythropoietin receptor (EPO binding protein (EBP)) has been expressed and overproduced in Escherichia coli. Regardless of the presence ofpelB or ompT signal sequences the recombinant protein produced in this fashion appears, as with many other recombinant eukaryotic proteins produced in E. coli as an insoluble product in laboratory scale fermentations. The induction product of the pelB protein expression system appears as two protein forms with slightly different molecular weights. Based on N-terminal sequence analysis of recovered protein, these forms represent two variants, one with the signal sequence properly processed to yield the expected "native" amino terminus and another which retains the signal sequence. Both forms appear as insoluble fermentation products. Control of oxygen levels and pH during high density fermentation allows the production of only the protein variant with the native amino terminus. Methods reported here permit the efficient recovery of purified EBP which quantitatively binds EPO in solution as determined by high performance size exclusion chromatography. A long-lived refolding intermediate was observed which penultimately collapses into an active conformation. The active purified protein competes with membrane associated EPO receptor for binding [125I]EPO and neutralizes EPO-dependent stimulation in a cell based proliferation assay. Further, the radioligand equilibrium binding constant for this interaction has been determined by immobilizing EBP on agarose gel via a free cysteine. The production of EBP by these methods should facilitate the structural determination of the protein by NMR or crystallography and may serve as a guide for the refolding of other hematopoietic receptors.

Pineal ganglioglioma with premature thelarche. Report of a case and review of the literature

We report a case of a 6-year-old girl with a ganglioglioma in the pineal region presenting with a rare clinical picture of premature thelarche. Intracranial gangliogliomas are rare, especially in the pineal region. Their character, origin, treatment, and prognosis remain controversial. The pathophysiology of precocious puberty associated with pineal ganglioglioma is discussed.

Disruption of RB/E2F-1 interaction by single point mutations in E2F-1 enhances S-phase entry and apoptosis

The retinoblastoma protein (RB) has been proposed to function as a negative regulator of cell proliferation by complexing with cellular proteins such as the transcription factor E2F. To study the biological consequences of the RB/E2F-1 interaction, point mutants of E2F-1 which fail to bind to RB were isolated by using the yeast two-hybrid system. Sequence analysis revealed that within the minimal 18-amino acid peptide of E2F-1 required for RB binding, five residues, Tyr (position 411), Glu (419), and Asp-Leu-Phe (423-425), are critical. These amino acids are conserved among the known E2F family members. While mutation of any of these five amino acids abolished binding to RB, all mutants retained their full transactivation potential. Expression of mutated E2F-1, when compared with that of wild-type, significantly accelerated entry into S phase and subsequent apoptosis. These results provide direct genetic evidence for the biological significance of the RB/E2F interaction and strongly suggest that the interplay between RB and E2F is critical for proper cell cycle progression.

T cell lymphoma in transgenic mice expressing the human Hsp70 gene

In the course of studying the role of hsp70 in the differentiation of pancreatic beta cells, transgenic founder mice were generated with the human hsp70 gene fused to the human insulin gene promoter. One resulted in a transgenic line that consistently developed diabetes mellitus, but unexpectedly three other independent transgenic founders developed generalized malignant lymphoma within 10 months after birth. Immunochemical and RT-PCR analyses revealed that the transgene was expressed in the lymphoma cells. Flow cytometric analyses revealed that the tumor was originated from T lymphocytes. Our results provide the first experimental evidence that hsp70 is involved in the tumorigenesis of T cells most likely through the blockage of apoptotic signals.