Distinct pattern of ret oncogene rearrangements in morphological variants of radiation-induced and sporadic thyroid papillary carcinomas in children.

In this study, we compare the morphological and genetic characteristics of 38 post-Chernobyl thyroid papillary carcinomas from Belarussian children 5-18 years old with those of 23 sporadic papillary carcinomas from the same age children without history of radiation exposure from Los Angeles and Cincinnati. Among radiation-induced tumors, solid variant of papillary carcinoma was found in 37%, follicular in 29%, typical papillary in 18%, and mixed and diffuse sclerosing variants in 8% each. In the sporadic group, a typical papillary pattern was prevalent in 70%, follicular in 17%, diffuse sclerosing variant in 9%, and solid in 4%. In both groups, the prevalence of ret rearrangements was high, but the frequency of specific types of rearrangement was significantly different. Among radiation-induced tumors, ret/PTC3 was found in 58%, ret/PTC1 in 16%, and ret/PTC2 in 3%, whereas among sporadic tumors, ret/PTC1 was found in 47% (P < 0.05), and ret/PTC3 was found in 18% (P = 0.01). The morphological variants of papillary carcinoma showed different prevalence of the specific types of ret rearrangement. Seventy-nine % of solid variant tumors had ret/PTC3, whereas only 7% had ret/PTC1 (P = 0.0007). Among typical papillary tumors, ret/PTC1 was found in 38%, ret/PTC3 in 19%, and ret/PTC2 in 5%. Thus, ret rearrangements are highly prevalent in pediatric papillary carcinomas from children exposed to radiation and in those occurring sporadically. However, the types of ret/PTC vary between these two populations, with ret/PTC3 present more commonly in post-Chernobyl tumors. Furthermore, solid variants have a high prevalence of ret/PTC3, whereas typical papillary carcinomas do not, suggesting that the different types of ret rearrangement confer neoplastic thyroid cells with distinct phenotypic properties.

Documentation of EWS gene rearrangements by fluorescence in-situ hybridization (FISH) in frozen sections of Ewing's sarcoma-peripheral primitive neuroectodermal tumor.

Prompt and accurate diagnosis of small round cell tumors warrants ancillary studies. Recently, two-color fluorescence in-situ hybridization (FISH) using probes for specific gene rearrangements has gained wide acceptance. EWS gene rearrangements, present in essentially 100% of Ewing's Sarcoma/peripheral primitive neuroectodermal tumor, were evaluated by FISH on frozen sections (FS) of tumor biopsies from 10 patients, plus a negative control, and in seven other malignant neoplasms of childhood. 4mu FS were hybridized overnight, using a single EWS gene-specific probe spanning the EWS breakpoint. We identified EWS rearrangements in 8 of 10 cases (80%) of Ewing's Sarcoma/pPNET. There are no known false positives in diploid or near-diploid tumors, or in any of the non-EWS tumors tested; the uncommon false negative can be confirmed by RT-PCR. Hyperdiploid cases with multiple copies of chromosome 22 may be better evaluated by two-color FISH. This is the first use on FS biopsy material of a single probe for EWS, capable of detecting all known EWS rearrangements, in ES and other tumors. Utilization of this ancillary technique on FS for ES/pPNET and other tumors with distinctive chromosomal translocation is highly specific, reliable, expeditious (24-36 hours) and cost-effective.

Systemic mast cell disease associated with primary ovarian mixed malignant germ cell tumor.

A 12-year-old girl with a mixed malignant germ cell tumor of the ovary, treated by surgery and chemotherapy, developed systemic mast cell disease (SMCD) approximately 3 months after chemotherapy. Hematologic malignancies have previously been noted in patients with mediastinal germ cell tumors but this is the first report of a primary ovarian germ cell neoplasm associated with SMCD.

Reverse transcriptase PCR amplification of EWS/FLI-1 fusion transcripts as a diagnostic test for peripheral primitive neuroectodermal tumors of childhood.

The peripheral primitive neuroectodermal tumors (pPNETs) of childhood, including Ewing's sarcoma, peripheral neuroepithelioma, and Askin's tumor, often present significant diagnostic challenges for the anatomic pathologist. One consistent feature of these tumors is the presence of the t(11;22)(q24;q12) in tumor cells, and this translocation has been useful as a marker for this group of tumors. The recent cloning of the t(11;22) breakpoint has revealed the fusion of the human FLI-1 gene on chromosome 11q24 with a gene of unknown function called EWS on 22q12, and fusion transcripts have been detected. These findings have raised the possibility of using molecular genetic analysis as a tool to diagnose pPNETs. To this end, we have tested pPNETs for the presence of EWS/FLI-1 fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) using EWS and FLI-1 specific primers. Eight (80%) of 10 pPNET cell lines were positive for amplified products using this technique. These results were confirmed by Southern analysis, which revealed rearrangements of EWS using genomic EWS probes in all eight positive cell lines. We then tested 20 primary pPNET tumors, and identified fusion transcripts by RT-PCR in 18 (90%) of these cases. Cloning and sequencing of PCR products confirmed the presence of EWS and FLI-1 sequences in these products. Furthermore, fusion transcripts were not detected by this technique in a series of non-pPNET pediatric solid tumors. Detection of EWS/FLI-1 fusion transcripts by RT-PCR therefore provides a novel adjunctive tool in the diagnosis of pPNETs.

Comparison of outcomes between living donor and cadaveric lung transplantation in children.

BACKGROUND: Long-term survival in lung transplant is limited by bronchiolitis obliterans (BOS). We compared outcomes in pediatric living donor bilateral lobar (LL) vs cadaveric lung transplant (CL). METHODS: Children were studied who had LL or CL with at least 1 year follow-up. Data collected included acute rejection episodes, pulmonary function tests (PFT), BOS, and survival. Mean age was 13.36+/-3.16 years in LL and 12.00+/-4.19 years in CL patients (p = 0.37, ns). RESULTS: There was no difference in rejection (p = 0.41, ns). CL had rejection earlier (2.48+/-3.84 months) than LL (13.60+/-10.74 months; p = 0.02). There was no difference in 12 month PFT. But at 24 months, LL had greater forced expiratory volume in 1 second (FEV1) (p = 0.001) and FEF25-71% (p = 0.01) than CL. BOS was found in 0/14 LL vs 9/11 (82%) CL after 1 year (p = 0.04). After 2 years, 0/8 LL and 6/7 (86%) CL had BOS (p < 0.05). LL had 85% survival vs 79% for CL at 12 months. At 24 months, LL survival was 77% vs 67% for CL. CONCLUSIONS: Pediatric LL had less BOS and better pulmonary function than CL. As BOS is a determinant of long-term outcome, we believe LL is the preferred lung transplant method for children.

The effects of topical prazosin on normal and elevated intraocular pressure and blood pressure in rabbits.

A 0.1 mg (base) dose of prazosin, a postsynaptic alpha- (alpha 1) adrenoceptor antagonist, in rabbits effected an early decrease in arterial blood pressure, normal intraocular pressure (IOP) and IOP artificially elevated by water loading. The late drug effects suppressed elevated IOP, but not normal IOP. The IOP effects of prazosin seem largely independent of the effect on blood pressure.

Pharmacokinetics of doxylamine given as Bendectin in the pregnant monkey and baboon.

The object of the present study was to determine the maternal plasma pharmacokinetics of doxylamine (the antihistamine component of Bendectin) following Bendectin administration. Bendectin was administered daily, po, at a dosage approximately 10 times the maximum human therapeutic dosage (7 mg/kg/day) throughout organogenesis (approximately days 22 through 50 of gestation) to three cynomolgus monkeys, four rhesus monkeys, and five baboons. Two pharmacokinetic experiments were performed in each animal, one on the first day of treatment and one on the last day of treatment. Although this study was not designed specifically as a teratologic examination, no morphologic abnormalities were observed when the fetuses were examined on approximately day 100 of gestation. A single-compartment, parallel first- and second-order elimination model was used to analyze the data. Although considerable interindividual variation was evident, no significant differences between species were observed when the half-life for the absorption of doxylamine from the gut or the elimination of doxylamine and metabolites from the plasma were compared. The plasma elimination half-lives and the clearance values were not altered by the 29 days of Bendectin treatment for any of the species. Only the half-life for the absorption of doxylamine in the baboon was reduced by daily dosing with Bendectin, but this did not alter doxylamine elimination. Thus, the pharmacokinetics of doxylamine administered as Bendectin were similar in the three nonhuman primate species examined and were not altered by repeated daily administration.

Steric structure activity relationships of various adrenergic agonists: ocular and systemic effects.

Dextrorotatory (d) forms of adrenergic drugs are known to be much less active than the levo (l) forms in effecting classical adrenergically mediated responses (alpha, beta 1, beta 2) in metabolic organs and cardiovascular tissues. Adrenoceptor intrinsic activity and affinity, enzymatic inactivation and neuronal uptake are all known to be relatively selective for the l-forms. It is known, however, that the d-isomers of certain agonists, such as isoproterenol, are as effective or even more effective ocular hypotensive agents than their respective l-forms or the racemates (dl) in rabbits. We tested the d- and l-isomers of epinephrine (alpha, beta 1, beta 2), norepinephrine (alpha, beta 1), phenylephrine (alpha 1), isoproterenol (beta 1, beta 2) and soterenol (alpha, beta 2) for their comparative effects after topical administration on intraocular pressure (IOP), pupil diameter (PD), arterial blood pressure (ABP) (after both topical and i.v. administration), aqueous cAMP, and aqueous and plasma lactate and glucose in the normotensive rabbit model. The results with ABP and concomitant changes in plasma biochemical correlates normally associated with adrenergic mechanisms were consistent with well established theory of stereospecificity. Data from ocular parameters, however, suggest that d-isomers of adrenergic agents evoke ocular responses that are divergent from this theory. The relation of ocular and systemic pressure responses with their respective biochemical correlates suggests that some d-isomers of adrenergic stimulants may be acting as partial agonists.

Studies on the circadian rhythm of IOP in rabbits: correlation with aqueous inflow and cAMP content.

We investigated the relationship of aqueous humor inflow rate and cyclic AMP concentrations to the spontaneous and dramatic changes in IOP associated with onset of darkness in our previously described model of circadian rhythm of intraocular pressure. After onset of darkness, rabbits entrained in an environment with a daily alternating cycle of 12 hours light and 12 hours darkness (12L:12D) showed an 85% increase in outflow pressure, a nearly 60% increase in aqueous inflow rate and an 80% increase in aqueous cAMP. Animals desynchronized by an unpredictable light cycle showed no increase in IOP or inflow rate when measured at the same time intervals as were the entrained animals. Thus, the IOP, aqueous inflow rate and aqueous cAMP are all seen to change in the same direction in a pharmacologically unperturbed rabbit eye. Previous pharmacological studies in rabbits have correlated an increase in cAMP with a decrease in IOP and aqueous inflow.

Ocular hypertensive response to beta-adrenoceptor agonists.

Acute administration of non-selective and relatively selective beta-adrenoceptor agonists elicit a monophasic fall in IOP. The present study indicates that unilateral application of certain beta-agonists on consecutive days can result in marked ocular hypertension. 1-Epinephrine, reproterol and 1-isoproterenol evoked an elevation of IOP on the second and third day after topical administration of a 2% solution in normal rabbits and in rabbits with surgically transected extraocular muscles. In contrast, the same concentration of d-isoproterenol produced hypotensive responses only when administered once daily for three consecutive days. Since d-isoproterenol did not cause a rise in IOP during chronic administration, the mechanism involved in the hypertensive response appears to be more sensitive to the levorotatory form. Administration of timolol inhibited the ocular hypertensive effect of epinephrine and reproterol. Since timolol lowers IOP by depressing formation of aqueous, it is suggested that the rise in IOP following chronic administration of beta-agonists possibly involves an increase in aqueous humor production.

Circadian rhythm in intraocular pressure: a rabbit model.

An animal model for study of the circadian rhythm in intraocular pressure (IOP) was developed using carefully maintained environmental lighting conditions. Highly predictable, precipitous increases and decreases in IOP of somewhat more than 10 mm Hg were found to be closely correlated with the onset of darkness and light, respectively. The daily spontaneous variations in IOP, once entrained, were maintained in constant darkness, but were eliminated by constant light, as is similarly seen in many mammalian systems. This model provides a novel means of investigating circadian IOP oscillation, which has been shown to be especially amplified in primary open angle glaucoma (POAG). This new rabbit model may also warrant consideration for use in screening ocular antihypertensive drugs since it could obviate the gross physiological manipulations and concomitant side effects inherent in the popular methods of inducing ocular hypertension in animal models.

Increased submucosal nerve trunk caliber in aganglionosis: a "positive" and objective finding in suction biopsies and segmental resections in Hirschsprung's disease.

OBJECTIVE: To establish the diagnostic usefulness of submucosal hypertrophic nerve trunk morphology in Hirschsprung's disease as a quantifiable parameter supportive of aganglionosis on hematoxylin-eosin-stained sections. DESIGN: We retrospectively evaluated size and density of submucosal nerves on hematoxylin-eosin-stained sections and S100 protein-stained sections of resected segments from 13 patients with Hirschsprung's disease, and in sections of 20 aganglionic and 50 ganglionic rectal suction biopsies. SETTING: All patients were seen at Childrens Hospital Los Angeles (Calif), a tertiary-care pediatric center; the age of patients at diagnosis or resection ranged between 2 days and 3 years. RESULTS: Aganglionic segments contain many distinct nerve trunks greater than 40 microm in diameter. Ganglionic segments/biopsies showed no nerve trunk larger than this threshold value (P approximately .0000). Nerve trunks of such caliber are rarely encountered in pathologic transition zones and sites of colostomy. CONCLUSIONS: Submucosal nerve trunks that are 40 microm or greater in diameter strongly correlate with abnormal innervation/aganglionosis. Use of this objective parameter in evaluating suction biopsies should be helpful in the morphologic diagnosis of Hirschsprung's disease in infancy and early childhood.

Gastric duplication-colonic fistula with colonic ulceration and bleeding.

An 11-month-old girl had massive rectal bleeding. A midabdominal mass was palpated. Ultrasound scan showed a large cystic mass with diffusely echogenic contents; Tc-99M radionuclide scan confirmed a duplication. Exploratory surgery and pathology examination showed a gastric duplication with formation of a fistula into the transverse colon with a colonic ulcer and hemorrhage. This combination of findings is presented as a rare cause of lower gastrointestinal hemorrhage in infancy.

Effects of adrenergic drugs on aqueous cAMP and cGMP and intraocular pressure.

The following variously selective adrenergic agonists were tested for their effects on the concentration of adenosine 3',5' cyclic monophosphate and guanosine 3',5- cyclic monophosphate in the aqueous humor of treated and fellow eyes of rabbits one hour after topical unilateral application (2 mg, base): Epinephrine (alpha, beta 1.beta 2), phenylephrine alpha), isoproterenol (beta 1, beta 2), tazolol (beta 1) and terbutaline (beta 2). All drugs produced a significant increase in cAMP in the treated eyes and all but terbutaline produced a significant increase in the fellow eye. Terbutaline alone caused an increased in cGMP although a similar dose of pilocarpine, a cholinergic agonist, was ineffective in changing cGMP levels. We conclude that (1) diverse adrenoceptor stimulation can increase cAMP, but (2) not necessarily in direct relation to an agent's hypotension induced by pilocarpine is not accompanied by an increase in aqueous cGMP.

Effect of beta-adrenergic drugs on plasma glucose and glucagon in Japanese quail: a preliminary report.

The present study was conducted to determine the effects of beta-adrenergic stimulation on plasma glucose and glucagon (IRG) levels in Japanese quail. Isoproterenol, epinephrine and three relatively selective beta-adrenoceptor agonists (terbutaline, salbutamol and reproterol) produced dose-related hyperglycemia and hypoglucagonemia. This study demonstrates that beta-adrenoceptor agonists produce hyperglycemia in birds as they do in mammals, but that the rise in plasma glucose in birds, unlike mammals, is accompanied by a profound fall in plasma IRG levels.

Comparative teratogenicity of triamcinolone acetonide, triamcinolone, and cortisol in the rat.

Pregnant rats were injected im with 0.5 mg/kg triamcinolone acetonide (TAC) on day 12, 13, or 14 of gestation and the fetuses were examined for cleft palate on day 20. All three TAC-treated groups showed an increased proportion of fetuses with cleft palate compared to an untreated control group. Only the group treated on day 13 showed a significant increase in the proportion of litters affected. This indicates that day 13 of gestation is the most sensitive day for cleft palate induction by TAC in the rat. Pregnant rats were then treated on day 13 of gestation with either TAC, triamcinolone (TA), or cortisol. TAC was 59 times as potent as TA in inducing cleft palate, with ED50 values of 1.1 mg/kg and 65 mg/kg respectively. Cortisol induced a significant increase in cleft palates at 500 mg/kg, but the efficacy of this compound was too low to calculate an ED50 and relative teratogenic potency value. Other developmental abnormalities including umbilical hernias, resorption, and fetal death resulted from TAC treatment. Fetal growth retardation was produced by all three compounds. The rank order of teratogenic potency was determined to be TAC greater than TA greater than cortisol.

Monomeric and dimeric copper(II) complexes of a novel tripodal peptide ligand: structures stabilized via hydrogen bonding or ligand sharing.

The novel tripodal ligand N-(bis(2-pyridyl)methyl)-2-pyridinecarboxamide (Py3AH) affords monomeric and dimeric copper(II) complexes with coordinated carboxamido nitrogens. Although many chloro-bridged dimeric copper(II) complexes are known, [Cu(Py3A)(Cl)] (1) remains monomeric and planar with a pendant pyridine and does not form either a chloro-bridged dimer or the ligand-shared dimeric complex [Cu(Py3A)(Cl)]2 (4) in solvents such as CH3CN. When 1 is dissolved in alcohols, square pyramidal alcohol adducts [Cu(Py3A)(Cl)(CH3OH)] (2) and [Cu(Py3A)(Cl)(C2H5OH)] (3) are readily formed. In 2 and 3, the ROH molecules are bound at axial site of copper(II) and the weak axial binding of the ROH molecule is strengthened by intramolecular hydrogen bonding between ROH and the pendant pyridine nitrogen. Two ligand-shared dimeric species [Cu(Py3A)(Cl)]2 (4) and [Cu(Py3A)]2(ClO4)2 (5) have also been synthesized in which the pendant pyridine of one [Cu(Py3A)] unit completes the coordination sphere of the other [Cu(Py3A)] neighbor. These ligand-shared dimers are obtained in aqueous solutions or in complete absence of chloride in the reaction mixtures.

Effects of ibuterol, a beta-2 adrenergic prodrug, on intraocular pressure.

Ibuterol, a prodrug of terbutaline, was approximately 100 times more potent than terbutaline in producing ocular hypotension in the treated eye of normal and sympathectomized (SX) rabbits. In normal rabbits, ibuterol produced no change in IOP of the contralateral eye whereas in unilaterally SX rabbits a rise in IOP occurred in the SX (contralateral) eye when the normal eye was treated with ibuterol. Ibuterol also suppressed ocular hypertension induced by water loading and delayed the IOP recovery rate although its onset of action was delayed. Aqueous flow was increased significantly at 1 hr after ibuterol in fluorophotometric studies in normal rabbits. Pretreatment with forskolin antagonized rather than enhanced ibuterol-induced ocular hypotension. Pretreatment with diclofenac failed to suppress the development of tachyphylaxis to the ocular hypotensive effect of ibuterol. Although ibuterol is an effective ocular hypotensive agent in rabbits, the effects of this agent on aqueous flow are complex and tachyphylaxis to the ocular hypotensive effect develops fairly rapidly.

Age-related marrow changes in the pelvis: MR and anatomic findings.

Short repetition time magnetic resonance images of the pelvis in 70 subjects (aged 1 day to 24 years) without history of bone marrow disease were retrospectively analyzed for the distribution and appearance of red and yellow marrow. The signal intensity and degree of mottling of marrow in six anatomic regions of the pelvis were observed and were assigned a grade. Anatomic correlation was provided with gross and microscopic examination of bone marrow biopsy specimens taken from selected pelvic sites in cadavers of children. Marrow signal intensity increased in all pelvic regions except the acetabulum from birth to age 24 years. Marrow heterogeneity was most prominent in the acetabulum at all ages. Patterns of bone marrow signal intensity and heterogeneity are recognized for four age groups: the infant, child, adolescent, and young adult. Regional and age-related differences in the signal intensity of pelvic marrow correlate with the percentage of fat seen microscopically in marrow.