Neonatal pontomedullary disconnection with aplasia or destruction of the lower brain stem: a case of pontoneocerebellar hypoplasia?

We report a neonate who presented with marked hypotonia and absent suck reflex. MR demonstrated complete absence of the pons as well as absence of a basilar artery flow void. Our case exhibits features similar to those described in previous reports of pontoneocerebellar hypoplasia, but with a more severe degree of pontine involvement. The associated vascular findings suggest a vascular insult to the brain stem as the cause.

Autoantigenic proteins that bind recombinogenic sequences in Epstein-Barr virus and cellular DNA

We have identified conserved autoantigenic cellular proteins that bind to G-rich sequence motifs in recombinogenic regions of Epstein-Barr virus (EBV) DNA. This binding activity, called TRBP, recognizes the EBV terminal repeats, a locus responsible for interconversion of linear and circular EBV DNA. We found that TRBP also binds to EBV DNA sequences involved in deletion of EBNA2, a gene product required for immortalization. We show that TRBP binds sequences present in repetitive cellular DNA, such as variable-number tandem repeats (VNTR) and immunoglobulin heavy-chain class switch regions. We propose that EBV utilizes cellular DNA recombination systems to mediate several types of viral genome alterations. These findings may lead to an understanding of the mechanism of rearrangements of EBV DNA that are a central feature of the biology of the virus.

EEG changes during open heart surgery on infants aged 6 months or less: relationship to early neurologic morbidity

In a prospective study, we analyzed the intraoperative electroencephalographic (EEG) changes during open heart surgery with deep hypothermia in 66 infants aged 6 months or younger, 70% of whom were neonates. Suppression of amplitude and continuity at the nadir of temperature reduction and following rewarming, and the appearance of periodic paroxysmal activity, was compared with neurologic abnormalities before and following operation, patient characteristics, and operation variables. EEG changes disclosed no relationship to abnormal neurologic findings, age at operation, type of anesthetic, duration of cardiopulmonary bypass (CPB), duration of low-flow CPB or cooling, temperature at circulatory arrest (HCA) or low flow, or nasopharyngeal-venous return temperature differences. EEG suppression following rewarming was associated with the use of thiopentone and duration of HCA. Use of thiopentone was also related to decreased levels of alertness at the end of the first postoperative week. We could not demonstrate any association between operation variables, including duration of HCA, and postoperative neurologic findings which include abnormalities of tone, alertness, seizures, generalized pyramidal signs, choreoathetosis, and hemiparesis. Severe hypotonia before operation was associated with continuing severe hypotonia during the postoperative period. EEG changes during cooling for open heart surgery on infants appear to be physiologic, and these plus EEG suppression following HCA or low-flow CPB are not useful predictors of early neurologic morbidity.

Inhibitory effects of antagonists of bombesin/gastrin releasing peptide (GRP) and somatostatin analog (RC-160) on growth of HT-29 human colon cancers in nude mice

Nude mice bearing xenografts of HT-29 human colon cancer cell line were treated for 4 weeks with somatostatin analog (RC-160), bombesin/gastrin releasing peptide (GRP) antagonists (RC-3095 and RC-3440). In three separate experiments somatostatin analog RC-160 (50 micrograms/day) released from microgranules significantly reduced tumor growth. Bombesin/GRP antagonists, RC-3095 and RC-3440 injected subcutaneously (s.c.) twice daily at a dose of 10 micrograms had the greatest and consistently significant inhibitory effect on tumor growth. RC-3095 given once daily s.c. at a dose of 20 micrograms was less effective. RC-3095 also inhibited metastatic tumor growth after intrasplenic injection of HT-29 cells in nude mice. Specific binding sites of somatostatin, bombesin and epidermal growth factor (EGF) were detected on intact HT-29 cells or on the membranes from HT-29 tumor xenografts. The inhibitory effects of bombesin antagonists on tumor growth were consistently linked with a significant down-regulation of EGF receptors. Bombesin/GRP antagonists and somatostatin analogs could be considered for the development of new hormonal therapies for colon cancer.

Comparing regions of the Epstein-Barr virus ZEBRA protein which function as transcriptional activating sequences in Saccharomyces cerevisiae and in B cells

The ZEBRA protein activates expression of Epstein-Barr virus early-lytic-cycle genes in human B lymphocytes. Here it is shown that ZEBRA also behaves as a sequence-specific transcriptional activator in Saccharomyces cerevisiae. Deletional mutagenesis defined three regions of ZEBRA that participate in activation in S. cerevisiae. These regions are designated YI (amino acids [aa] 1 to 25), YII (aa 51 to 102), and YIII (aa 228 to 245). Two of the three regions of the native ZEBRA protein act together to mediate activation when assayed on ZEBRA binding sites. However, when fused to the DNA binding domain of GAL4 and assayed on GAL4 binding sites, regions YII and YIII were each sufficient to confer activation in S. cerevisiae. Regions of ZEBRA which affected activation in S. cerevisiae were also required in human B lymphocytes. The amino-terminal region of ZEBRA (aa 1 to 98) was required for activation both in S. cerevisiae and in human B cells; deletion of the carboxy-terminal 18 aa also significantly reduced activation in both cell types. Thus, the behavior of ZEBRA in human B cells and S. cerevisiae suggests that the protein contains universal activation motifs that interact with conserved components of the transcription machinery. However, certain deletion mutants of ZEBRA containing mutations in the N-terminal region exhibited discordant behaviors in S. cerevisiae and in B cells. For example, deletion of ZEBRA aa 26 to 51 impaired activation to a great extent in B cells but had little or no effect in S. cerevisiae. The discordant mutants may reflect interactions with a variable domain of a conserved component or unique interactions with specialized components of the basal transcription apparatus in different cells.

Serine-173 of the Epstein-Barr virus ZEBRA protein is required for DNA binding and is a target for casein kinase II phosphorylation

An Epstein-Barr virus-encoded protein, ZEBRA, mediates the switch from latency to the viral lytic life cycle. ZEBRA's domain structure and DNA binding specificity resemble that of cellular transcriptional activators such as c-Fos/c-Jun. We show that ZEBRA, like c-Jun, is phosphorylated by casein kinase II (CKII). The principal site of phosphorylation is serine-173 (S173), five amino acids upstream of the basic DNA recognition domain. CKII phosphorylation abrogated ZEBRA's capacity to bind its target DNA sequences. S173 is a functional component of ZEBRA's DNA binding domain, since mutation of S173 to alanine (S173A) reduced DNA binding in vitro to 10% of wild-type levels. Transcriptional activation of a native viral promoter in vivo by mutant S173A was also reduced markedly. Reversible phosphorylation of S173 is likely to be an important means of regulating ZEBRA's activity in vivo.

Differentiating acute appendicitis from pelvic inflammatory disease in women of childbearing age

A retrospective study was performed to evaluate the usefulness of various historical, clinical, and laboratory findings in differentiating acute appendicitis from pelvic inflammatory disease (PID) in women of childbearing age. The records of all female patients presenting to the emergency department with abdominal pain who were found to have histologically proven appendicitis (n = 80) or PID confirmed on endocervical culture (n = 71) were reviewed. Clinically useful indicators favoring appendicitis included the presence of anorexia and the onset of pain later than day 14 of the menstrual cycle. Indicators favoring PID included a history of vaginal discharge, urinary symptoms, prior PID, tenderness outside the right lower quadrant, cervical motion tenderness, vaginal discharge on pelvic examination, and positive urinalysis. Despite these indicators, differentiating acute appendicitis from PID remains difficult.

Data collection and changing health care systems. 1. United Kingdom

The adoption of "Read Clinical Codes" for computerised patient records could profoundly alter the nature and quality of Western medicine in the next decade. The increasing awareness of the need for a standardised coding system has led to the funding of a pilot project to test Read codes in Australian general practice. Read codes are a comprehensive nomenclature of clinical terms incorporating over 100,000 codes in a structured hierarchical form. Designed by a general practitioner, they are now owned, controlled, and developed by the British National Health Service (NHS). Selected as the basis for clinical coding across the NHS, they form the cornerstone of computerised patient records. Computer use has been encouraged in general practice in the UK, with financing schemes and functional inducements resulting in 70% of practices being at least partly computerised, and 84% of these using Read codes. Their promotion has been backed by a major development program to broaden the codes to include all clinical specialities, nursing, and professions allied to medicine. The codes will require significant adaptation for Australian use, including the development of an administrative chapter and a pharmaceutical classification. The impact of information management systems on health care in the UK has relevance for the continuing development of the Australian National Health Information Strategy and for future record keeping in general practice in Australia. If the trial proves successful, the adoption of Read codes as a standard for information management in patient medical records will need to be considered.

Data collection and changing health care systems. 2. New Zealand

Radical changes planned in the New Zealand health system aim to improve its cost effectiveness, quality and consumer responsiveness. These changes will take place despite a paucity of data on the use of resources and outcomes. Data collection systems are to be introduced into hospitals and primary care with the use of the Read clinical codes (RCC) in addition to ICD-9-CM (International classification of disease--clinical modification) and ICPC (International classification of primary care). This paper discusses the proposed changes to the New Zealand health care system and describes their effect on the present and future data collection methods in general practice.

Characterization and transcriptional regulation of the 2'-N-acetyltransferase gene from Providencia stuartii

We have cloned the chromosomally encoded 2'-N-acetyltransferase gene [aac(2')-Ia] from Providencia stuartii. DNA sequence analysis of the cloned insert identified a single open reading frame, which is capable of encoding a protein with a predicted molecular mass of 20,073 Da. The deduced AAC(2')-Ia protein showed no significant homology to other proteins, including all of the AAC(3) and AAC(6') proteins. Primer extension analysis was used to identify the aac(2')-Ia promoter, which contained an unusual sequence (CTTTTT) at the -35 region. Expression of the aac(2')-Ia gene occurs at low levels in wild-type P. stuartii strains; therefore, they are aminoglycoside susceptible. We have isolated mutants with high-level AAC(2')-Ia expression at a frequency of 4.8 x 10(-6). Detailed analysis of one mutant demonstrated a 12.2-fold increase in the accumulation of aac(2')-Ia mRNA. In addition, the levels of beta-galactosidase expression from a plasmid-encoded aac(2')-lacZ transcriptional fusion were increased 11.5-fold in this mutant relative to those in an isogenic wild-type strain. These results suggested that a trans-acting factor, designated aar (for aminoglycoside acetyltransferase regulator), controls AAC(2')-Ia expression in P. stuartii.

Systemic and mucosal humoral responses to Helicobacter pylori in gastric cancer

The systemic IgG response to Helicobacter pylori was examined in 70 patients with gastric cancer. H pylori IgG antibodies were assayed by enzyme linked immunosorbent assay (ELISA), and serological recognition of H pylori antigens was characterised by western blotting. A percentage of 78.5 were seropositive by ELISA. Two of five patients under age 50 were seronegative. Positivity was unrelated to age, sex, tumour type, or site. Ninety one per cent of ELISA positive cancer patients recognised the H pylori cytotoxin associated 120 kilodalton (kD) protein, significantly more than a control group of 47 ELISA positive patients with non-ulcer dyspepsia (72%). Four of 15 ELISA negative cancer patients also showed recognition of this protein in western blots. Mucosal IgA responses to H pylori were examined by immunoblotting supernatants of in vitro cultured resected antral mucosa in an overlapping group of 19 gastric cancer patients. Eighteen had a positive response, including 10 of 11 negative for H pylori by biopsy urease testing. The systemic and local immunoblotting results show that the high seroprevalence of H pylori antibodies detected by ELISA is nevertheless an underestimate of past infection. Dyspepsia screening policies based solely on H pylori ELISA would miss some young patients with gastric cancer. Further study of the relation of the H pylori cytotoxin to gastric precancerous lesions is warranted.

In situ detection of lytic Epstein-Barr virus infection: expression of the NotI early gene and viral interleukin-10 late gene in clinical specimens

Riboprobes that detect two genes expressed only during productive infection were developed to characterize the clinical spectrum of Epstein-Barr virus (EBV) lytic infection and identify diseases that may be responsive to antiviral drug therapy. The NotI antisense probe hybridizes to tandem repeats in the abundant early lytic cycle BHLF1 mRNA. Transcripts were detected in lytically infected cell lines, AIDS-associated oral hairy leukoplakia, bone marrow of a patient with virus-associated hemophagocytic syndrome, and spleen of an AIDS patient but not in EBV-positive primary central nervous system lymphomas or in circulating EBV-infected B cells from a patient with acute infectious mononucleosis. The viral (v) interleukin-10 (IL-10) probe hybridizes to the unique 5' end of the late lytic cycle BCRF1 mRNA, which encodes a protein homologous to the human cytokine IL-10. The vIL-10 probe detected transcripts in lytically infected cell lines and within the differentiated layers of oral hairy leukoplakia.

An epidemiologic study of nosocomial infections in a pediatric long-term care facility

OBJECTIVE

To determine the incidence of hospital-acquired (nosocomial) infection in pediatric long-term care facilities.

DESIGN

Prospective cohort.

SETTING

An 87-bed pediatric long-term care facility.

PATIENTS

All patients receiving long-term care at Bloorview Children's Hospital during the study period.

RESULTS

Infection developed in 40.1% of patients (n = 456). The nosocomial infection rate per 1000 patient days (mean, 7.84) varied substantially, from 1.66 in May 1988 to 16.37 day in April, 1989. The proportional frequencies of infections were as follows: respiratory, 41.6% (37.0% upper, 4.6% lower); urinary tract, 31.0%; skin, 15.6% (gastric tube site 5.0%, other 10.6%), eyes, 6.4%; gastrointestinal, 3.5%; and other, 1.5%. Of those infections for which an organism was recovered (48.5%), pathogens included Escherichia coli (22.5%), Enterococcus (14.8%), Staphylococcus (14.8%), Streptococcus (11.2%), Klebsiella (10.5%), Pseudomonas (10.1%), Proteus (4.3%), yeast (4.3%), Salmonella (0.7%), Clostridium difficile (0.4%), and other (6.2%).

CONCLUSIONS

The incidence and nature of infections in pediatric long-term care facilities differs from those in acute care facilities. Physicians should become familiar with the infection rates in the populations whom they treat. Control requires compliance with currently recognized effective strategies as well as innovative practical approaches to respiratory disease. Behavioral problems related to frequent clean, intermittent catheterization in young adults need to be addressed.

Changing Epstein-Barr viral ZEBRA protein into a more powerful activator enhances its capacity to disrupt latency

The Epstein-Barr viral transcriptional activator ZEBRA induces expression of viral early lytic genes when introduced into cells bearing latent Epstein-Barr virus. We show here that a ZEBRA-herpes simplex viral protein 16 (VP16) fusion protein induces early viral lytic gene expression in Epstein-Barr virus-containing cells more efficiently than does wild-type ZEBRA. The fusion protein is also a more powerful transcriptional activator in these cells, as assayed with reporter constructs. Our experiments also suggest that ZEBRA manifests a function required for full activity on certain natural promoters but not on promoters bearing oligomerized ZEBRA binding sites; this function cannot be provided by VP16.

Does war stress contribute to hypertension?

Veterans often apply to the Department of Veterans' Affairs to have their hypertension accepted as related to their war service. Claims may be rejected on the grounds that stress does not affect hypertension. Veterans' organisations often recommend an appeal and general practitioners may then become involved. This article was written to help the practitioner advise the veteran and explains why hypertension may be granted on appeal.

An evaluation of two compact analyzers used for lipid analysis

BACKGROUND

A number of relatively inexpensive compact analyzers are available for use in physician offices and outpatient clinics to measure total cholesterol and, more recently, high-density lipoprotein (HDL) cholesterol and triglycerides. This study was designed to document the analytical performance of two of them, the Abbott Vision and the Kodak Ektachem DT60, for assays of total cholesterol, HDL cholesterol, triglycerides, and calculated low-density lipoprotein (LDL) cholesterol.

METHODS

Lipid profiles were measured from venous blood samples of 70 subjects with each test device, and results were compared with those from a laboratory standardized to the Centers for Disease Control. Coefficient of variation (CV) of multiple measurements from three pools of human serum (ie, precision), mean percent difference between device and standard laboratory results (ie, accuracy or bias), and 95% tolerance intervals (total error) were determined. The correct classification of patients into risk categories with device results was compared with the standardized laboratory results.

RESULTS

The average CVs for total cholesterol, triglycerides, and HDL cholesterol with the Vision analyzer were 3.6%, 4.4%, and 10.5%, respectively, and with the DT60, 5.0%, 4.1%, and 6.8%, respectively. The average percent biases for the same analytes with the Vision analyzer were 0.2%, 4.0%, and -2.3%, respectively, and with the DT60, -2.1%, 12.1%, and 0.1%, respectively. Total error assessments indicated that total and HDL cholesterol measurements in individual patients met the guidelines of the National Cholesterol Education Program with both devices, but that triglycerides and LDL cholesterol measurements did not. Classification of subjects into risk groups based on total or LDL cholesterol gave clinically satisfactory results with either device.

CONCLUSIONS

More precise measurement technology for LDL cholesterol is needed. Physicians and others who rely on compact analyzer results for diagnosis and treatment decisions should consider the degree of inaccuracy and imprecision in these values.

SCH 38057: a picornavirus capsid-binding molecule with antiviral activity after the initial stage of viral uncoating

The activity of a new water-soluble molecule, SCH 38057, against picornaviruses is described. SCH 38057 inhibited plaque formation of selected entero- and rhinoviruses in a range of 10.2 to 29.1 microM (50% endpoint) and had a therapeutic index of 10 against poliovirus type 2 (polio 2) in HeLa cells. When administered orally or subcutaneously, SCH 38057 protected mice infected with either coxsackievirus B3 (CVB3) or echovirus-9 from mortality. The molecule provided a low level of protection against thermal inactivation of virus, indicating that SCH 38057 interacts with the picornavirus capsid. Binding studies with [3H]SCH 38057 revealed that the molecule binds to CVB3 and human rhinovirus 14 (HRV14) in a ratio of 29 and 19 molecules per viral particle, respectively. The affinity constant for SCH 38057 binding to CVB3 was 7.0 x 10(-4) M. When added to cultures of infected cells at 3 h after infection, SCH 38057 markedly inhibited viral RNA synthesis. This finding with lack of inhibition of attachment and loss of infectious virus after attachment were interpreted to indicate that, although SCH 38057 binds to the viral capsid, the molecule exerts its antiviral effect after the initial stage of picornavirus uncoating, i.e., after conversion of the 156S infectious viral particle to smaller subviral species.

Autoreactive T cells from a type I diabetic recognize multiple class II products

Mononuclear cells obtained from a child at the acute presentation of type I diabetes were stimulated in vitro with human insulin followed by IL-2 and IL-4. All of the T-cell clones isolated from this stimulation were autoreactive, recognizing autologous B cells in the absence of insulin or other exogenous antigens. Eleven CD4+ clones were studied in detail to identify the class II MHC antigens stimulating these autoreactive cells. The donor was heterozygous for DR3DQw2 and DR4DQw3.2 haplotypes, a combination of alleles with a greatly increased risk for type I diabetes. The clones demonstrated skewed recognition of class II antigens. Three clones appeared to recognize a peptide derived from one class II beta chain (DR beta 1, DR4Dw4) presented by another class II beta chain (DR beta 4, DRw53). Three clones were stimulated by cells expressing DPw4 molecules. Only one clone recognized a product derived from the DR3 haplotype. In contrast to both antigen-specific and autoreactive T-cell clones derived from normal individuals, many of the autoreactive T cells isolated from this subject were stimulated by class II molecules other than DR beta 1. The results support the hypothesis that autoreactive T cells recognize autologous peptides in association with MHC and some of these peptides are derived from self MHC molecules.

Quantitative leukoviremia and immune complex-dissociated antigenemia as predictors of infection status in children born to mothers infected with human immunodeficiency virus type 1

Four methods of culturing human immunodeficiency virus type 1 (HIV-1) from peripheral blood mononuclear cells and two serum antigen tests were assessed as predictors of infection status in children born to HIV-1-infected mothers. Of 36 infants whose cocultures were quantitative, all 15 who were deemed to be infected with HIV-1 (nine with symptoms, six without symptoms) by clinical criteria or persistence of Western blot reactive antibody had positive culture results, and all 21 uninfected seroreverters had negative culture results (sensitivity = 100%; specificity = 100%). Quantitative coculture was more sensitive than a technique in which cells were counted and stimulated with phytohemagglutin but not cocultivated with cells from seronegative donors, and more sensitive than two other qualitative techniques evaluated in samples from 80 children, in which cells were not enumerated before culture. The level of leukoviremia in children with symptoms did not differ appreciably from the level of leukoviremia in symptom-free infected children. Among those with positive results on quantitative coculture, only 40% also had free HIV-1 antigen in serum, whereas 86% had antigen in immune complexes. Among the methods evaluated, quantitative HIV-1 coculture was the best indicator of infection status in children.