Graphitization of Glassy Carbon after Compression at Room Temperature.

Glassy carbon is a technologically important material with isotropic properties that is nongraphitizing up to ∼3000 °C and displays complete or "superelastic" recovery from large compression. The pressure limit of these properties is not yet known. Here we use experiments and modeling to show permanent densification, and preferred orientation occurs in glassy carbon loaded to 45 GPa and above, where 45 GPa represents the limit to the superelastic and nongraphitizing properties of the material. The changes are explained by a transformation from its sp^{2} rich starting structure to a sp^{3} rich phase that reverts to fully sp^{2} bonded oriented graphite during pressure release.

Sedation of children for technical procedures: current standard of practice.

We sought to define the current standard of care for children undergoing sedation for painless diagnostic procedures by sending questionnaires to 284 pediatric residency program directors in North America. From the 89 responses, we determined that departments of pediatrics set sedation policies for children in most institutions, often with formal written guidelines for these procedures. Most require that children have some form of cardiorespiratory monitoring while under sedation and that they are attended by individuals trained in cardiorespiratory resuscitation until the child is fully recovered. The use of parents to transport and monitor the sedated child is uncommon, and total lack of monitoring is rare. Chloral hydrate in dosages of 25 mg/kg to 100 mg/kg is the most common drug used for sedation; DPT, a combination of parenteral Demerol (meperidine), Phenergan (promethazine), and Thorazine (chlorpromazine), at a maximum dose of 2 mg/1 mg/1 mg/kg is the second; and pentobarbital in a dosage of 5 mg/kg to 7 mg/kg is the third. These sedation regimens were associated with few serious side effects, except that two deaths were reported in infants with congenital heart disease who were sedated with DPT. We believe this survey may reflect the current standard of practice for sedation in North American infants and children undergoing diagnostic procedures.

Serine proteinase of Renibacterium salmoninarum digests a major autologous extracellular and cell-surface protein.

Renibacterium salmoninarum is a pathogen of salmonid fish that produces large amounts of extracellular protein (ECP) during growth. A proteolytic activity present in ECP at elevated temperatures digested the majority of the proteins in ECP. This digestion was also associated with the loss of ECP immunosuppressive function. In vitro activity of the proteinase in ECP was temperature dependent: it was not detected in an 18-h digest at 4 and 17 degrees C but became readily apparent at 37 degrees C. Proteinase activity was detected at bacterial physiological temperatures (17 degrees C) in reactions incubated for several days. Under these conditions, digestion of partially purified p57, a major constituent of ECP and a major cell-surface protein, yielded a spectrum of breakdown products similar in molecular weight and antigenicity to those in ECP. This pattern of digestion suggests that most of the immunologically related constituents of ECP are p57 and its breakdown products. The proteolytic activity was sensitive to phenylmethylsulfonyl fluoride, methanol, and ethanol and to 10-min incubation at temperatures above 65 degrees C. Electrophoretic analysis of the proteinase on polyacrylamide gels containing proteinase substrates indicated the native form to be 100 kDa or greater. The enzyme was active against selected unrelated substrates only when coincubated with a denaturant (0.1% lauryl sulfate) and (or) a reducing agent (20 mM dithiothreitol).

Congenital atransferrinemia. A case report and review of the literature.

A four-year-old Polynesian girl with a two-year history of severe microcytic, hypochromic anemia (which was refractory to iron therapy) had a decreased beta-globulin fraction on serum protein electrophoresis, resulting from the absence of the transferrin (TRF) band. Subsequent assays for TRF showed a level below the detectable range. Liver biopsy revealed significant deposition of hemosiderin within hepatocytes and Kupffer cells, in addition to early fibrosis. Two bone marrow aspirates were hypercellular, with decreased myeloid-erythroid ratios. This case represents the eighth reported example of congenital atransferrinemia, a rare, apparently autosomal recessive disease.

Tropical splenomegaly syndrome associated with cytomegalovirus infection.

The tropical splenomegaly syndrome (TSS) is characterized by massive splenomegaly with hypersplenism, moderate hepatomegaly, and lymphocytic infiltration of the hepatic sinusoids. In previous reports this syndrome has been shown to be a consequence of a disordered immunologic response of the host to malarial infection. Treatment with antimalarial drugs has resulted in a decrease in malarial antibody titers and a reduction in splenic size. We report a child who had TSS associated with cytomegalovirus infection rather than malaria. Our results suggest that TSS may be precipitated by a variety of infections producing chronic antigenic stimulation and perhaps by autoantigenic stimulation as well.

Survival after isolated cerebral mucormycosis.

Cerebral mucormycosis is a rare disorder caused by several genera of the family Mucoraceae. The genera Rhizopus, Absidia, and Mucor are the predominant pathogenic groups. Disease caused by these organisms usually complicates an underlying chronic illness, such as diabetes mellitus or malignancy. Cerebral involvement usually occurs from an ascending infection from the paranasal sinuses via the orbit and is usually associated with poorly controlled diabetes. The pulmonary system is the most common site of infection in patients with leukemia. Isolated cerebral mucormycosis not associated with head trauma or intravenous drug abuse is a rare disorder. We report what we believe to be the first successfully treated case of isolated cerebral mucormycosis in a patient with acute lymphocytic leukemia in remission.

Unsuspected prostatic adenocarcinoma in patients who have undergone radical cystoprostatectomy for transitional cell carcinoma of the bladder.

In 45 of 165 male cystectomy patients with bladder cancer (27 per cent) incidental adenocarcinoma of the prostate was found during the diagnostic evaluation or histological examination of the cystoprostatectomy specimens. Of the patients 37 had stage A1 or A2 and 8 had stage C or D1 prostate cancer. Clinical presentation, stage and grade distributions for each primary and prognostic variable are reviewed. Over-all, 67 per cent of the patients currently are alive with a 3-year actuarial survival rate of 60 per cent. The presence of incidental stage C or D1 prostate cancer in the surgical specimen implies incomplete surgical excision and it may warrant additional postoperative treatment. However, a significantly increased mortality rate among these patients has not been identified during the limited median followup of 25 months.

Bleomycin nodules mimicking metastatic osteogenic sarcoma.

Patients with osteogenic sarcoma are at a very high risk of developing pulmonary metastatic disease. Bleomycin has recently been reported to cause pulmonary nodules mimicking metastatic disease. Our case adds what we believe to be the first report in the pediatric literature and describes new findings that we believe are so suggestive of bleomycin nodules that immediate biopsy to exclude metastatic disease may not be necessary.

Use of health care by chronically ill children in rural Florida.

Factors that influence ambulatory care (visits to physicians and emergency rooms) and use of hospitals were investigated in a population of chronically ill, rural, low-income children. Rates of use for this population--a stratified random sample of 672 Medicaid-eligible children under age 17 years who lived in a 24-county area of northern Florida--were similar to those in a national study of chronically ill children. Further, the rates were shown to increase significantly as limitations to activity increased. Younger children and white children were also shown to have significantly higher use rates than older children and black children. Despite these associations, and those related to primary diagnoses, none of the analyses were able to explain much of the variation in the use of health care resources. The findings were similar to those of other studies; thus, the identification of the relatively small numbers of children who consume relatively large amounts of health care remains elusive.

The prognostic significance of age and pattern of metastases in stage IV-S neuroblastoma.

Stage IV-S neuroblastoma is a unique disseminated neoplasia characterized by remote disease to the liver, skin, or bone marrow. Stage IV-S patients have frequent spontaneous remissions and a 60% to 90% survival rate. Many investigators have recommended minimal or no therapeutic intervention; however, some patients do experience progressive disease and ultimately die of neuroblastoma. Many authors have commented on single prognostic factors such as age and site of metastatic involvement. Five newborns were recently seen at Walter Reed Army Medical Center with Stage IV-S neuroblastoma. Four of these children died of mechanical complications associated with massive hepatomegaly, prompting this review of Stage IV-S neuroblastoma to determine prognostic factors.

Health care provider and family acceptance of a rural community-based nursing service for chronically ill children.

Health care providers' and families' overall acceptance of a community-based nursing program was assessed in relationship to their perceptions of the program nurses' accessibility, professional competence, and personal qualities. Perceptions were measured by questionnaires completed by 139 health care providers and 140 families. Overall, providers indicated that the program has been of benefit to both the children it serves and the medical community. The majority of families felt that the nurses were helpful to them despite a few complaints related to poor availability.

School absence among children with chronic illness.

This paper reports school attendance for 336 chronically ill, Medicaid-eligible children living in rural areas of northern Florida. Demographic data were obtained by a questionnaire administered in a home interview. Attendance data were collected directly from the schools. The mean number of days absent the previous year was 16.9; the mean percentage of days absent was 9.4%. Regression analysis indicated that lower education level of parents and the child's inability to participate in physical activities were significant in predicting days missed from school. No individual diagnostic category was predictive of school absence. Thus, the chronicity of an illness and its impact on the child may be a more significant influence on school attendance than the actual diagnosis of the illness.

State and Federal expenditures on Medicaid eligible chronically ill children in rural Florida.

This paper details public (State and Federal) expenditures for children's health care among Medicaid eligible chronically ill children resident in a rural setting. Of the cases, 78.5% had an expenditure in the study year with an average per capita total expenditure of +604. The mean total expenditure was considerably higher than the median total expenditure (+142), i.e. there was a relatively small proportion of high cost cases. Inpatient services accounted for 54.2% of total expenditures despite the fact that only 12% of the cases had been hospitalized. Wide variation in total expenditures, both within and among disease categories, was noted. By implication, while substantial savings might be realized from efforts directed at reducing health care costs for a small subset of the population, the identification of that subpopulation remains elusive.