The neuroblastoma amplified gene, NAG: genomic structure and characterisation of the 7.3 kb transcript predominantly expressed in neuroblastoma.

Amplification of the MYCN oncogene in neuroblastoma is associated with poor prognosis. The amplified unit of DNA can be up to 1 Mb in size and so could contain additional genes which affect tumour phenotype. The neuroblastoma amplified gene (NAG) gene was initially located 400 kb telomeric to MYCN at 2p24 and reported to be co-amplified in 5/8 (63%) cell lines and 9/13 (70%) tumours. The sequence of a 4.5 kb transcript was proposed from the analysis of overlapping cDNA clones. However, our Northern blot hybridisation experiments indicate that the main RNA species expressed in neuroblastoma is 7-8 kb in size. We describe for the first time the cloning and sequencing of the 7.3 kb transcript of the NAG gene together with its precise genomic location and full exon structure. The 5' end of the gene is located 30 kb telomeric to DDX1, with the two genes lying in opposite orientations. The 52 exons of the 7.3 kb transcript cover 420 kb of genomic DNA. In vitro translation studies confirmed the protein coding potential of the transcript. Co-amplification of the entire NAG gene with MYCN was found in 1/6 (17%) neuroblastoma cell lines and 10/50 (20%) primary tumours. Previous studies had measured co-amplification of only the 5' end of the gene, nearest to MYCN. In this study, co-amplification of the NAG gene was found to be significantly associated with low disease stage in MYCN-amplified tumours (P=0.0063).

The effects of circulating interleukin-8 and adhesion molecules on pulmonary dysfunction in pediatric orthotopic liver transplantation.

We investigated the effects of circulating inflammatory cytokines and adhesion molecules induced by ortho-topic liver transplantation (OLT) on pulmonary function. Although the plasma interleukin-8 (IL-8) levels increased gradually, peaking at the end of the operation, these increases were considered minimal. The baseline endothelial adhesion molecule (E-selectin) level was several times higher than the normal value, but after reperfusion of the new transplanted liver, the plasma E-selectin concentrations decreased to within the normal range and remained almost normal during the postoperative period. Similar changes were observed in the plasma levels of other types of adhesion molecules. Although PaO(2)/FIO(2) showed a significant inversed correlation with the peak IL-8 concentration, after the exclusion of two patients, one of whom died and one of whom rejected the transplanted liver, no correlation was able to be found between the PaO(2)/FIO(2) ratio and the maximum IL-8 concentration. Furthermore, there was no correlation between the adhesion moleclues and PaO(2)/FIO(2). These results suggest that IL-8 exerts only a slight effect on respiratory function following successful pediatric liver transplantation, and that circulating adhesion molecules do not affect perioperative lung function.

Waterlogging effects on growth and yield components in late-planted soybean.

A major agronomic problem in the southeastern USA is low yield of late-planted soybean [Glycine max (L.) Merr.]. This problem is aggravated by the adverse effect of waterlogging on crop growth. Our objectives were to identify soybean growth stages sensitive to waterlogging; identify yield components and physiological parameters explaining yield losses induced by waterlogging; and determine the extent of yield losses induced by waterlogging under natural field conditions. Greenhouse and field studies were conducted during 1993 and 1994 near Baton Rouge, LA, (30 degrees N Lat) on a Commerce silt loam. Waterlogging tolerance was assessed in cultivar Centennial (Maturity Group VI) at three vegetative and five reproductive growth stages by maintaining the water level at the soil surface in a greenhouse study. Using the same cultivar, we evaluated the effect of drainage in the field for late-planted soybean. Rain episodes determined the timing of waterlogging; redox potential and oxygen concentration of the soil were used to quantify the intensity of waterlogging stress. Results of the greenhouse study indicated that the early vegetative period (V2) and the early reproductive stages (R1, R3, and R5) were most sensitive to waterlogging. Three to 5 cm of rain per day falling on poorly drained soil was sufficient to reduce crop growth rate, resulting in a yield decline from 2453 to 1550 kg ha-1. Yield loss in both field and greenhouse studies was induced primarily by decreased pod production resulting from fewer pods per reproductive node. In conclusion, waterlogging was determined to be an important stress for late-planted soybean in high rainfall areas such as the Gulf Coast Region.

A transient increase in endogeneous erythropoietin levels after paediatric liver transplantation.

We investigated whether liver transplantation affects endogeneous erythropoietin (EPO) synthesis. Serum EPO levels were measured before transplantation and during the peri-transplant period in ten consecutive paediatric patients who had received a liver allograft without recombinant EPO therapy. All patients were anaemic on post-operative day 1 (POD 1); however, the haemoglobin levels of three patients gradually increased and required phlebotomy on POD 5-9. The serum levels of EPO in all patients were within the normal range before surgery, but six of the ten patients had a transient increased level of EPO at 1248 h after transplantation. A transient increase of endogeneous EPO following paediatric liver transplantation may be associated with extramedullary erythropoiesis in human liver grafts.

High incidence of postoperative pulmonary complications after orthotopic liver transplantation in children.

Postoperative pulmonary complications were investigated in a total of 41 pediatric recipients who underwent orthotopic liver transplantation (OLT) between January, 1990 and March, 1992 at the Royal Children's Hospital, Brisbane. Atelectasis was seen in 40 cases (98%) of the 41 recipients, and occurred in the left lower lobe in 28 cases (68%), and in the right upper lobe in 25 cases (61%). Radiographic pulmonary edema occurred on 23 occasions in 18 recipients (45%). Pulmonary edema was observed just after operation in 9 cases, and in the later stage from the 3rd to 25th postoperative day in 14 cases. Five recipients experienced two episodes of pulmonary edema during their ICU stay. The duration of mechanical ventilatory support was significantly longer in the patients with pulmonary edema than in those without (9.6±3.8vs 3.9±2.2 days,P<0.01). Pleural effusions were observed in 21 cases (52%), of which 18 had right-sided effusion and 3 had bilateral effusions. Pneumothorax occurred in three cases. Pyothorax, hemothorax, bronchial asthma, and subglottic granulation occurred in one case each. The present study demonstrated that postoperative pulmonary complications are frequently observed in pediatric recipients undergoing OLT.

Grand challenges in biomedical computing.

Advances in computing technology (both algorithms and hardware) over the next several years promise to make increasingly sophisticated computer modeling of biomedical phenomena a routine part of biomedical research. Improvements in both the absolute speed of processors and in their programming and graphics interfaces will allow nonexpert users to bring computing power equivalent to the supercomputers of a few years ago to bear on routine research problems and to display complex data in understandable ways (visualization). Although biomedical applications have traditionally not driven the leading edge of computing and supercomputing, such applications are increasingly being ported to advanced parallel and vector processors. This paper summarizes the current state of biomedical computing, citing examples of the best practice in research today. A number of projects enabled by advanced computing from various subdisciplines are described. Trends in technology for both inexpensive (workstation) and high-end computing (vector supercomputers and parallel processors) are cited; the implications of these for biomedical computing are discussed. "Grand challenges" in biomedical computing, i.e., computational problems of major scientific importance that are beyond our current capabilities but that might be achieved in a 5-year time frame, are outlined.

Spironolactone and estrogen-progestin therapy for hirsutism.

Sixteen women with hirsutism used spironolactone, 100 mg daily without interruption, plus norethindrone (1 mg) and ethinyl estradiol (35 mg) for 21 of each 28 days. Clinical improvement occurred in 11 of the 16 patients and also in an additional patient when the dose of spironolactone was increased to 200 mg daily. Spironolactone 100 mg daily plus norethindrone and ethinyl estradiol resulted in significant reduction in serum total testosterone, serum free testosterone, and percentage of free testosterone. Side effects were infrequent.

High-molecular weight dextran in human infertility surgery.

The use of intraperitoneal 32% high-molecular weight dextran 70 (Hyskon, Pharmacia Inc.) has been reported to reduce the incidence of surgical adhesions in several species. The present study was undertaken to determine the effect of 32% dextran 70 in human females who underwent major abdominal infertility operations. Adhesions were quantitated by means of standardized objective criteria in 44 women in a prospective, randomized, double-blind study, and reevaluated at second-look laparoscopy approximately 6 weeks later. The mean change in the adhesion score for all patients in the 32% dextran 70 group (n = 23) was -2.57 units (i.e., clinically "improved") versus +2.41 units (i.e., clinically "worsened") in the control group (n = 21), p = 0.016. For the subgroup of patients who underwent lysis of adhesions, the 32% dextran 70 group (n = 17) improved significantly, whereas the control group (n = 12) tended not to improve with careful technique alone (-4.2 units versus +0.3 unit, p less than 0.05). These data indicate that 32% dextran 70 not only significantly reduces the formation of adhesions overall in human infertility operations, but also is highly effective in reducing the reformation of adhesions after lysis.

Nocturnal prolactin levels in infertility.

Since serum prolactin rises during sleep in normal women, nocturnal serum prolactin concentrations were determined every 30 minutes in follicular phase and again in luteal phase in 13 regularly menstruating infertile women with daytime normoprolactinemia, 8 of whom had luteal phase defects. When compared with controls, there was an increased serum prolactin elevation in 7 women. Six of the women with nocturnal hyperprolactinemia took bromocriptine for two menstrual cycles. This treatment eliminated the excessive nocturnal prolactin rise but did not result in consistent improvement in endometrial development. Polytomographic findings compatible with a pituitary microadenoma were seen in 5 of 7 women with nocturnal hyperprolactinemia. Random daytime prolactin levels may be normal in infertile women who have nocturnal hyperprolactinemia associated with x-ray evidence of pituitary microadenoma.

Effect of cyproheptadine on chlorpromazine stimulation of prolactin in women.

In five normal women, the expected chlorpromazine-induced rise in serum prolactin was inhibited by pretreatment with a serotonin antagonist, cyproheptadine. This indicated that the serotoninergic system has an excitatory effect on the release of prolactin. When similar studies were done in nine women with hyperprolactinemia and galactorrhea, the administration of chlorpromazine did not consistently produce a rise in serum prolactin, and pretreatment with cyproheptadine did not have a predictable effect. In most cases, this chlorpromazine-induced reduction in the prolactin inhibitory factor could not further increase the secretion of prolactin, so that there was no rise to inhibit.

Identification of differing etiologies of clinically diagnosed premature menopause.

Investigations were performed in eight young women to determine if the findings of secondary amenorrhea and high follicle-stimulating hormone levels were due to primary ovarian follicular atresia or to other causes. Karyotypes were determined from both peripheral leukocytes and ovarian tissue; one woman had XXX/XX/XO mosaicism. Another woman had normal ovarian histology and probably had the "gonadotropin-resistant ovary syndrome." No autoimmune antibodies were detected, but one woman with myasthenia gravis also had ovarian histology that demonstrated primary ova and a developing follicle. Only five of eight women had primary ovarian follicular atresia, and two of the other three women had conditions theoretically compatible with subsequent pregnancy.

Effects of alpha- and beta-adrenergic blocking agents on serum prolactin levels in women with hyperprolactinemia and galactorrhea.

The effects of alpha- and beta-adrenergic blocking agents on the serum prolactin levels of six women with hyperprolactinemia and galactorrhea were investigated. There was no indication that pituitary adenomas were etiologic agents for the hyperprolactinemia. Serum prolactin could be lowered with oral L-dopa. When intravenous phentolamine (an alpha-adrenergic blocking agent) or intravenous propranolol (a beta-adrenergic blocking agent) were administered for 1 hour, there was no significant change in serum prolactin levels.