Transcription of c-mos protooncogene in the pig involves both tissue-specific promoters and alternative polyadenylation sites

The function of the c-mos gene has been intensively studied, but its role in the mammal is still a subject for debate. For this reason, and because the gene is regulated posttranscriptionally, further study of the gene from other mammalian species is timely. The pig c-mos gene has been cloned, and the genomic sequence is presented here. The gene has no introns and shows close similarity to human and monkey genes, with striking sequence similarities in both the 5' and 3' flanking regions. The significance of this similarity in the context of gene regulation is discussed. c-mos expression was found to be restricted to gonadal tissues in the pig. The major start sites for transcription initiation in ovary and testis were identified by primer extension and found to be distinct, as in the mouse. Within the ovary, expression is confined to oocytes. Messenger RNA is synthesized in growing oocytes, and remains stable during oocyte maturation, but begins to be degraded in electrically stimulated eggs. Unexpectedly, RNase protection assays revealed that the 3' ends of transcripts in the pig ovary are heterogeneous, and this, together with the identification of three distinct cDNA clones, shows that multiple polyadenylation sites are used. The significance of these transcripts in terms of translational control is discussed.

Genetic and environmental influences on insulin levels and the insulin resistance syndrome: an analysis of women twins

Multiple factors may determine insulin resistance and the insulin resistance syndrome. The contributions of genes and environment to the distribution of fasting insulin levels and to the associations of fasting insulin with elements of the syndrome were evaluated in the second examination of the Kaiser Permanente Women Twins Study (Oakland, California, 1989-1990). Subjects included 556 white women (165 monozygous twin pairs, 113 dizygous pairs; 455 women with normal glucose tolerance, 75 with impaired glucose tolerance, and 26 with non-insulin-dependent diabetes by World Health Organization criteria). The intraclass correlation coefficients for log fasting insulin for monozygous and dizygous twin pairs were 0.64 and 0.40, respectively. After adjustment for age, behavioral factors, and body mass index, the estimated classic heritability was 0.53 (p = 0.003). Commingling analysis of fasting insulin indicated the presence of four distributions (p < 0.001), consistent with at least one, and perhaps two, genes influencing this trait. In an unmatched multiple regression model among women from monozygous twin pairs only, log fasting insulin was independently associated with body mass index (p < 0.0001), waist/hip ratio (p = 0.02), and glucose intolerance (p = 0.04), but not with triglycerides, high density lipoprotein cholesterol, or hypertension. After removal of genetic influences by analysis of monozygous intrapair differences, only body mass index (p < 0.0001) remained independently related to fasting insulin. The authors conclude that, in addition to significant genetic influences on fasting insulin, environmental or behavioral factors (particularly nongenetic variation in obesity) are important determinants of fasting insulin and the insulin resistance syndrome.

Bronchial arteriovenous malformation in a child with hemoptysis. A case report

Pulmonary arteriovenous (AV) malformations occur sporadically and in the pediatric population are most commonly associated with hereditary hemorrhagic telangiectasia. Hemoptysis is an infrequent presentation in this age group. Pulmonary angiography is considered to be the definitive diagnostic modality. The authors describe an otherwise healthy eleven-year- old girl who presented with massive hemoptysis secondary to a large bronchial AV malformation unrelated to any congenital anomalies. The pulmonary angiogram appeared normal and the diagnosis was established by digital subtraction aortography. Successful embolotherapy was performed by selective injection of polyvinyl alcohol particles into the culprit bronchial artery.

Imaging of post-transplant spindle cell tumors

Spindle/smooth muscle cell proliferation is an additional neoplastic process related to immunosuppression and EBV infection. We describe four post transplant children with this diagnosis. Multiple organ systems may be involved, particularly the liver, gastrointestinal tract, and lungs. Lesions are radiographically, clinically, and endoscopically indistinguishable from those of post-transplant lymphoproliferative disease (PTLD).

Ultrasonographic evaluation of birth injury to the shoulder

Injuries of the proximal humerus in infants are often missed or misinterpreted because the humeral epiphysis is frequently nonossified. Ultrasonography enables direct visualization of the proximal humeral epiphysis, metaphysis, joint space, and relationship of the epiphysis with the glenoid cavity. We describe an infant with unexplained agitation and ventilatory difficulty related to a fracture of the proximal right humerus that was not appreciable on plain film radiographs. Sonographic imaging of the shoulder, with use of the opposite side for comparison, clearly demonstrated a Salter I proximal humeral fracture with marked metaphyseal displacement and preservation of the normal epiphyseal-glenoid relationship.

Rapid reporting of cancer incidence in a population-based study of breast cancer: one constructive use of a central cancer registry

To support a study of genetic risk factors for breast cancer, the North Carolina Central Cancer Registry has implemented a rapid reporting procedure for hospitals in the study area. This system permits the identification of newly diagnosed breast cancer cases within a very short time period (less than one month). The procedures are straightforward, cost-effective, and greatly benefit the objectives of tissue collection and interviews with the cases. This article describes the rapid reporting procedures and their potential impact for population-based research. For the objective of making generalizable risk statements, the necessity of population-based research is stressed; participation with central cancer registries is endorsed for this and other molecular epidemiologic applications.

Studying environmental influences and breast cancer risk: suggestions for an integrated population-based approach

Increased attention has focused in recent years on environmental exposures which may elevate risk of human breast cancer. Following a brief introduction to the topic, we present a summary of recent evidence regarding the role of chlorinated hydrocarbons (e.g. pesticides), occupational exposures (e.g. electromagnetic fields), dietary factors, and other hydrocarbons (e.g. tobacco). Next, we present suggestions for additional measurements which may help to clarify the contribution of environmental factors, including individual and ecologic level exposure histories, polymorphisms in carcinogen-metabolizing enzymes, and interactions among environmental exposures, breast tumor characteristics, and other risk factors for breast cancer. Finally, we discuss how a population-based approach may be used to integrate these sources of information and could provide new clues regarding the role of environmental influences in breast cancer.

The Carolina Breast Cancer Study: integrating population-based epidemiology and molecular biology

The integration of epidemiology and molecular biology provides a new strategy to identify additional risk factors for breast cancer and to better understand the role played by traditionally recognized risk factors. The Carolina Breast Cancer Study (CBCS) is a population-based, case-control study designed to identify causes of breast cancer among Caucasian and African-American women who are residents of a 24-county area of central and eastern North Carolina. Information on established and potential breast cancer risk factors is obtained by personal interviews. Blood samples are collected from all consenting participants. Medical record documentation and paraffin-embedded tumor specimens are obtained for all breast cancer patients. DNA from tumor tissue is tested for a variety of molecular alterations characteristic of breast cancer. Germline DNA from blood lymphocytes is evaluated for presence of alleles increasing susceptibility to breast cancer. Statistical analyses evaluate gene-environment interaction by exploring the associations between environmental/behavioral factors and breast cancer in relation to specific molecular alterations (germline and tumor). Results will help identify high-risk women, clarify causal pathways, and hopefully contribute to the prevention of breast cancer.

Effect of pulse dexamethasone therapy on the incidence and severity of chronic lung disease in the very low birth weight infant

We conducted a prospective, randomized, double-blind trial to assess the efficacy and safety of pulse doses of dexamethasone on survival without supplemental oxygen in very low birth weight infants at high risk of having chronic lung disease. Seventy-eight infants with birth weights < or = 1500 gm who were ventilator dependent at 7 days of postnatal age were randomly assigned to receive pulse doses of dexamethasone, 0.5 mg/kg per day, divided twice daily (n = 39), or an equivalent volume of saline solution placebo (n = 39), for 3 days at 10-day intervals until they no longer required supplemental oxygen or assisted ventilation, or reached 36 weeks of postmenstrual age. At study entry, the groups did not differ by birth weight, gestational age, or severity of lung disease. At 36 weeks of postmenstrual age, there was both a significant increase in survival rates without oxygen supplementation (p = 0.03) and a significant decrease in the incidence of chronic lung disease (p = 0.047) in the group that received pulse therapy. Supplemental oxygen requirements were less throughout the study period in the group that received repeated pulse doses of dexamethasone (p = 0.013). The total numbers of deaths and the durations of supplemental oxygen, ventilator support, and hospital stay did not differ between groups. Recorded side effects in the pulse therapy group were minimal and included an increase in the use of insulin therapy for hyperglycemia (p < 0.05). We conclude that in this population of very low birth weight infants, treatment with pulse doses of dexamethasone resulted in improvement in pulmonary outcome without clinically significant side effects.

The detection of varicella zoster antibodies by simultaneous competitive EIA and its comparison with radioimmunoassay, latex agglutination and antiglobulin type EIA

A rapid and simultaneous competitive enzyme immunoassay (EIA) for the detection of human antibodies to varicella zoster virus (VZV) which utilises complement fixing (CF) VZV antigen and peroxidase labelled human antibodies to VZV as reagents is described. The competitive EIA was compared with competitive radioimmunoassay (RIA) in a selection of sera from 501 blood donors and 115 patients. The competitive EIA was comparable in sensitivity and specificity to the RIA, but had the advantage of not requiring radiolabelling or facilities for radioactive handling and disposal, and also had an enhanced stability. The competitive EIA was compared with competitive RIA, a commercially available latex agglutination assay and an antiglobulin type EIA on sera from 100 patients. The competitive EIA and RIA appeared to be the most sensitive tests.

Lobar emphysema associated with respiratory syncytial virus pneumonia

The etiology of infantile lobar emphysema is frequently unknown; however, partial airway obstruction is most often implicated. Although infection and lobar emphysema have been linked previously, their cause-and-effect relationship is unclear. We present the clinical, radiographic, and pathologic findings in a 9-day-old infant with acute bronchiolitis due to respiratory syncytial virus (RSV) and a clinical and radiographic appearance suggestive of lobar emphysema. Pathologically, there was diffuse papillary overgrowth of the bronchiolar epithelium due to RSV infection which produced narrowing of the affected airways and alveolar overinflation. We speculate that in this instance RSV infection was at least associated with the development, and was perhaps the direct cause of lobar emphysema.

Multivariate analysis of the insulin resistance syndrome in women

The insulin resistance syndrome (IRS) is characterized by a constellation of interrelated coronary heart disease (CHD) risk factors, including dyslipidemia, obesity, central obesity, elevated systolic blood pressure, and hyperinsulinemia. Factor analysis was used to investigate the clustering of these risk factors in individuals by examining the correlational structure among these variables. Data from 281 genetically unrelated nondiabetic women who participated in exam 2 (1979 to 1980) of the Kaiser Permanente Women Twins Study were used. Factor analysis reduced 10 correlated risk factors to 3 uncorrelated factors, each reflecting a different aspect of the IRS: factor 1 (increased body weight, waist circumference, fasting insulin, and glucose), factor 2 (increased postload and fasting glucose and insulin and systolic blood pressure), and factor 3 (larger low-density lipoprotein particles, decreased plasma triglycerides, and increased high-density lipoprotein). Together, the factors explained nearly 66% of the total variance in the data. Thus, factor analysis defined three distinct aspects of the IRS in this sample of nondiabetic women. These factors may reflect separate underlying mechanisms of the syndrome, each of which may also be involved in CHD risk.

Left main bronchus compression after arterial switch for transposition

A case of left main bronchus obstruction after an arterial switch is described. The clinical features and successful management are described, and a mechanism for this complication is proposed.

Internalization of Escherichia coli into human kidney epithelial cells: comparison of fecal and pyelonephritis-associated strains

A gentamicin survival assay, using primary human renal epithelial cells and Escherichia coli strains isolated from the feces of asymptomatic individuals and from the urine or blood of patients with acute pyelonephritis, was used to investigate bacterial internalization as a model for renal parenchymal invasion in pyelonephritis. E. coli strains, regardless of their origin, efficiently entered into human renal epithelial cells, a process inhibited by cytochalasin D. While the percentage of survival of nonhemolytic pyelonephritis isolates did not differ from that of fecal isolates, survival of hemolytic pyelonephritis strains was lower than that of nonhemolytic strains, perhaps as a consequence of the greater cytotoxicity of hemolytic strains. There was no evidence of intracellular multiplication of E. coli. These results demonstrate that human renal epithelial cells are capable of efficient uptake of E. coli regardless of the source of the bacteria.

Recognition of malposition of the liver and spleen: CT, MRI, nuclear scan and fluoroscopic imaging

Thirteen children initially suspected to have an intrathoracic or intraabdominal mass had malposition of the liver and/or spleen discovered by ultrasound. This group consisted of five children with diaphragmatic eventration or hernia and eight with wandering spleen or liver. Careful ultrasonographic examinations were diagnostic in all patients; seven had surgical confirmation. CT, MRI, nuclear scan and fluoroscopic imaging were useful in select instances. The liver and spleen have a characteristic anatomic configuration and sonographic appearance that should enable them to be recognized, and pathological alterations appreciated, even when these organs are ectopic in location or malformed.

Iatrogenic tracheobronchial perforation in infants

We describe the clinical and radiographic features of four premature infants with acute iatrogenic tracheobronchial perforation by endotracheal tube (ETT) placement. One tube penetrated posteriorly into the esophagus, one directly through the carina; one perforated the right main bronchus posteriorly; and one breached the site of a recently repaired tracheoesophageal fistula. In only one infant was the intubation procedure clinically recognized to be traumatic. Radiographs obtained for tube placement demonstrated inferior malposition of the ETT in all four babies, decreased pulmonary aeration in three of four, acute retrocardiac infraazygos pneumomediastinum in three of four, and acute pleural effusion in one of four. Two infants developed progressive air leak and died in spite of drainage with multiple chest tubes; two survived and did well with conservative management. An additional eight cases have been previously reported, with an overall mortality of 58%. Prompt recognition of acute airway perforation can be lifesaving. Unexpected respiratory distress after intubation associated with acute infraazygos pneumomediastinum strongly suggests this entity.

Proteus syndrome: emphasis on the pulmonary manifestations

Published articles on the radiologic aspects of Proteus syndrome are sparse. This report highlights the features of this disease with specific attention to the serious pulmonary manifestations that may occur at an early age. Two cases of Proteus syndrome and severe lung disease are presented, with complete autopsy in one case and correlative surgical pathologic data in the other. Multiple superficial and visceral vascular abnormalities were present in both cases. Both patients developed rapidly progressive diffuse cystic emphysematous pulmonary disease leading to the death of one patient at age 18 years and a heart-lung transplant in the other at age 8 1/2 years. Extensive gross pulmonary cysts were evident pathologically with diffuse panlobar emphysema microscopically. Studies of collagen and cultured fibroblasts in one patient revealed no abnormality. The early presentation, rapid progression and potentially lethal nature of lung involvement has not previously been emphasized.

Pavlovian conditioning of the tickle response of human subjects: temporal and delay conditioning

Previous studies of the human response to a tickle have demonstrated that subjects will respond to a gesture that signals the onset of a tickle in the same way as to a tickle. Researchers have described this anticipatory response as an "expectation." In the current study, we investigated, from the Pavlovian framework, the response to a verbal stimulus preceding the tickle stimulus. We exposed subjects to experimental phases which included the Neutral Stimulus Alone, 100% Pairing of the Neutral and Unconditioned Stimuli (tickle strokes to the foot), Random Presentation, Partial (75%) Reinforcement, and Temporal Conditioning. Pavlovian conditioning was observed in all phases, suggesting a parsimonious explanation for the expectation effect described by others.