Peptides that block hepatitis B virus assembly: analysis by cryomicroscopy, mutagenesis and transfection

Peptides selected to bind to hepatitis B virus (HBV) core protein block interaction with the long viral surface antigen (L-HBsAg) in vitro. High resolution electron cryomicroscopy showed that one such peptide binds at the tips of the spikes of the core protein shell. The peptides contain two basic residues; changing either of two acidic residues at the spike tip to an alanine greatly reduced the binding affinity. Transfection of hepatoma cells with a replication-competent HBV plasmid gave significantly reduced production of virus in the presence of peptide, in a dose-dependent manner. These experiments show that the interaction of L-HBsAg with core particles is critical for HBV assembly, and give proof of principle for its disruption in vivo by small molecules.

Chimeric brains generated by intraventricular transplantation of fetal human brain cells into embryonic rats

Limited experimental access to the central nervous system (CNS) is a key problem in the study of human neural development, disease, and regeneration. We have addressed this problem by generating neural chimeras composed of human and rodent cells. Fetal human brain cells implanted into the cerebral ventricles of embryonic rats incorporate individually into all major compartments of the brain, generating widespread CNS chimerism. The human cells differentiate into neurons, astrocytes, and oligodendrocytes, which populate the host fore-, mid-, and hindbrain. These chimeras provide a unique model to study human neural cell migration and differentiation in a functional nervous system.

Growth and fate of PSA-NCAM+ precursors of the postnatal brain

Oligodendrocyte-type 2 astrocyte (O-2A) lineage cells are derived from multipotential stem cells of the developing CNS. Precursors of O-2A progenitors express the polysialylated (PSA) form of the neural cell adhesion molecule (NCAM) and are detected in neonatal rat brain glial cultures. It is unclear how such PSA-NCAM+ "pre-progenitors" are related to neural stem cells and whether they still have the potential to differentiate along several neural lineages. Here we isolated PSA-NCAM+ pre-progenitor cells from glial cultures by immunopanning and found that most of these cells expressed nestin and PDGF-receptor-alpha but not O-2A antigens. PSA-NCAM+ cells synthesized transcripts for fibroblast growth factor (FGF) receptors 1, 2, and 3 and responded to FGF2 by survival and proliferation, growing into large clusters resembling neural spheres. FGF2-induced proliferation of PSA-NCAM+ pre-progenitors was significantly enhanced by thyroid hormone (T3), which on its own did not increase cell survival or mitosis. After adhesion and withdrawal of the mitogen, spheres generated mostly oligodendrocytes and astrocytes but very rarely neurons. PSA-NCAM immunopanned cells grown in epidermal growth factor (EGF) also adopted a mostly glial fate after differentiation. In contrast, PSA-NCAM-negative cells and striatal neonatal stem cells, grown in EGF or FGF2, generated the three CNS cell types. Like neural stem cells, PSA-negative cells generated more oligodendrocytes and fewer neurons when expanded in FGF2 and T3. Thus emergence of PSA-NCAM at the surface of neonatal brain precursors coincides with their restriction to a glial fate. T3 modulates these events by enhancing PSA-NCAM+ pre-progenitor growth in FGF2 and favoring an oligodendrocyte fate.

Influence of bromodeoxyuridine radiosensitization on malignant glioma patient survival: a retrospective comparison of survival data from the Northern California Oncology Group (NCOG) and Radiation Therapy Oncology Group trials (RTOG) for glioblastoma multiforme and anaplastic astrocytoma

PURPOSE

To examine the effect of treatment using Bromodeoxyuridine (BrdU) during radiation therapy on malignant glioma patient survival by comparing historical survival data from several large clinical trials.

METHODS

A retrospective analysis of patient data from Radiation Therapy Oncology Group (RTOG) trials 74-01, 79-18, and 83-02 and the Northern California Oncology Group (NCOG) study 6G-82-1 was conducted. Patient data was supplied by both groups, and analyzed by the RTOG. Pretreatment characteristics including age, extent of surgery, Karnofsky Performance Status (KPS), and histopathology were collected; the only treatment variable evaluated was the use of BrdU during radiation therapy. Radiation dose, dose-fractionation schedule, use of chemotherapy, and/or type of chemotherapy was not controlled for in the analyses. Univariate and multivariate analyses were conducted to examine the potential treatment effect of BrdU on patient survival.

RESULTS

Data from 334 patients treated with BrdU on NCOG 6G-82-1 and 1743 patients treated without BrdU on 3 RTOG studies was received. Patients were excluded from the review if confirmation of eligibility could not be obtained, if the patient was ineligible for the study they entered, if central pathology review was not done, or if radiotherapy data was not available. Patients treated according to the RTOG studies had to start radiotherapy within 4 weeks of surgery; no such restriction existed for the NCOG studies. To ensure comparability between the studies, patients from the NCOG studies who began treatment longer than 40 days from surgery were also excluded. The final data set included 296 cases from the NCOG studies (89%) and 1478 cases from the RTOG studies (85%). For patients with glioblastoma multiforme (GBM) the median survival was 9.8 months in the RTOG studies and 13.0 months in the NCOG trial (p < 0.0001). For patients with AA the median survival was 35.1 months for the RTOG studies and 42.8 months in the NCOG trial (p = 0.126). Univariate results showed consistent results favoring BrdU among patients over 30 years of age, across the extent of surgery, and for GBM patients. A proportional hazards regression model that included treatment, histopathology, KPS, age, and extent of surgery demonstrated that treatment with BrdU was included in the best model only for the GBM group of patients (risk ratio 0.83).

CONCLUSIONS

Because of the heterogeneity of the treatment groups, including potentially important differences in pathology reviewers assessment of nonglioblastoma cases, differences in radiation dose and schedules, and chemotherapy during or after radiation, these analyses cannot provide the definitive answer as to whether BrdU given during radiation therapy improves survival in patients with malignant glioma. There does appear to be a favorable treatment effect seen in patients with GBM, with a lesser effect in patients with AA.

The need for assessment of sedation in the critically ill

There is a need for assessment of sedation in ICU as sedative agents are potent drugs that are used frequently but not regularly monitored for their efficacy. Critical care nurses are accountable when administering potent intravenous drugs, such as sedative agents. This paper examines the rationale behind the use of sedation in ICU. A number of sedative drugs commonly used in ICU, such as propofol, are highlighted. Sedation assessment tools available are considered but each may be appropriate in different situations.

Organisation of basement membrane components in the human adult and fetal pituitary gland and in pituitary adenomas

Cell-matrix interactions undoubtedly have a role in the development and maintenance of the complex nonrandom structure of the human pituitary gland. We have extended previous studies by documenting the patterns of immunoreactivity for type IV collagen, laminin and fibronectin in the fetal gland, comparing these with the adult patterns. In both we have examined the differences between the anterior lobe and intermediate zone in an attempt to elucidate the apparent differences in functional response between corticotrophs in the two areas. We have also examined expression of these proteins in a series of pituitary adenomas. Finally, we have immunolocalised beta 4 integrin, a component of the alpha 6 beta 4 laminin receptor, in the adult gland and in adenomas. In the anterior lobe of the adult gland, type IV collagen and laminin were present in both epithelial and vascular basement membrane. Fibronectin was related to the basement membrane but showed a less continuous distribution. beta 4 Integrin was expressed on the basal aspects of pituitary cells, in association with laminin, suggesting that this did identify the alpha 6 beta 4 laminin receptor. In addition, immunoreactivity was present on the lateral margins of some pituitary cells, which might indicate a role in cell-cell adhesion. None of the proteins showed specific association with any particular cell type, suggesting that these specific interactions do not regulate differentiation. This pattern of expression had developed in the fetal gland by the second trimester, with expression relating to vessels preceding that in epithelial basement membrane. Type IV collagen, laminin and fibronectin were also expressed in epithelial and vascular basement membrane in the intermediate zone of the adult gland, and around Rathke's cleft in the fetal gland. However, the organisation differed, with larger groups of cells enclosed within a single basement membrane. Possible vascular connections demonstrated between the posterior lobe and the intermediate zone would permit access of posterior lobe hormones to this zone. Our data confirmed disruption of expression in pituitary adenomas, type IV collagen, laminin and beta 4 integrin having a mainly perivascular distribution, with more variable immunoreactivity for fibronectin.

Emergence of oligodendrocytes from human neural spheres

To study the development of human oligodendrocyte precursors (OP), we expanded human embryonic brain-derived neural precursors into spheres with basic fibroblast growth factor (FGF2). Over 90% of the cells in the expanded spheres were precursors coexpressing nestin and the polysialylated (PSA) form of NCAM. The remaining cells were mostly astrocytes and neuronal cells located at the periphery of the floating spheres. When spheres were allowed to adhere on fibronectin-coated substrate in the absence of FGF2, neural precursors migrated in the outgrowth and often formed chains of cells expressing high levels of PSA-NCAM. Many migrating cells also expressed beta-3 tubulin while only scattered elongated cells radiating from the spheres were GFAP+ astrocytes. Spindle-shaped cells not associated with the chains were labeled for the PDGF-alpha receptor and often coexpressed MAP2 neuronal isoforms. Neuronal cells in the outgrowth rapidly established a rich neuritic network where OP expressing O4 and DM20/proteolipid antigens appeared. T3 treatment of neural spheres increased the rate of OP formation and the complexity of their shape. Thus, the generation of human oligodendrocytes from neural precursors is tightly correlated with growth of neuronal processes and enhanced by hormonal signals.

Long-term health outcomes and quality of life in American and Italian inception cohorts of patients with juvenile rheumatoid arthritis. I. Outcome status

OBJECTIVE

To assess the long-term health outcomes and quality of life of patients with juvenile rheumatoid arthritis (JRA) using health and functional assessment questionnaires in 2 populations, one from the USA and one from Italy.

METHODS

Patient eligibility criteria: (1) first examined in our units between 1958 and 1990 during the first 6 months after onset of symptoms, (2) diagnosis of JRA by the American College of Rheumatology criteria, (3) disease duration of at least 5 years at the time of assessment of outcome. Instruments used: (1) the Health Assessment Questionnaire (HAQ, short form, or childhood HAQ (CHAQ), and (2) Quality of Life Scales (QOLS, adults only). Eligible patients were identified by computer search and chart review and were then mailed a packet containing a consent/assent form and the assessment instruments.

RESULTS

Of 346 patients who met the eligibility criteria were able to locate 301, and 290 verbally agreed to participate and were mailed packets. Signed consent and complete information were received from 227 of the 290 (78%), 178 from the USA and 49 from Italy. Mean duration of disease at the time of outcome assessment was 15 yrs. 127 had pauciarticular, 55 polyarticular, and 45 systemic onset disease. Mean and (median) scores of the outcomes are shown in the table. [table: see text]

CONCLUSION

Long-term outcome, as assessed by the instruments used, is very favorable in most patients with JRA 5 years or more after onset of symptoms.

The Bentham Unit: a pilot remand and assessment service for male mentally disordered remand prisoners. I: Clinical activity in the first year, and related ethical, practical and funding issues

BACKGROUND

Because of continuing concern regarding the inadequacy of existing NHS provision for mentally disordered remand prisoners, the Bentham Unit was commissioned as a pilot project to provide rapid assessment and, where appropriate, hospital admission for such prisoners from the former North West Thames catchment area.

METHOD

Information is presented on the 150 referrals and 62 admissions in the first year of the service's operation.

RESULTS

The service met the Reed Report targets for assessment time. Most of those referred were previously known to psychiatric services. The alleged offences were more serious than anticipated. Those admitted were transferred to appropriate services at the conclusion of their court cases, and remained in contact with services three months later. Waiting for the conclusion of court proceedings significantly prolonged the length of stay. Substantial cost transfers from the criminal justice system to the health system were evident.

CONCLUSIONS

Adequate services for mentally disordered remand prisoners are entirely achievable; provision of such services is a resource issue, not a clinical problem.

Long-term health outcomes and quality of life in American and Italian inception cohorts of patients with juvenile rheumatoid arthritis. II. Early predictors of outcome

OBJECTIVE

To determine whether demographic, clinical, and immunogenetic variables measurable during the first 6 months of illness long-term health outcomes and quality of life in patients with juvenile rheumatoid arthritis (JRA).

METHODS

Patient eligibility criteria: (1) first examined in our units between 1958 and 1990 within 6 months of onset of symptoms; (2) diagnosis of JRA by American College of Rheumatology criteria; (3) disease duration of at least 5 years at the time of assessment of outcome. Instruments used: (1) the Health Assessment Questionnaire (HAQ, short form), or Childhood HAQ (CHAQ) to measure disability (0-3 scale), (2) pain, and (3) parental assessment of overall well being, each scored on a 15 cm visual analog scale; (4) the Quality of Life Scales (QOLS) (adults only). Independent variables that showed significant results using univariate tests underwent multiple logistic regression analysis.

RESULTS

227 patients were available for analysis. Mean duration of disease at time of assessment of outcome was 15 years (range 5.3-36.1). Univariate tests allowed 11 variables for disability, 9 for pain, 7 for overall well being, and 4 for QOL into the multivariate analysis. The best predictor of higher disability was the articular severity score (odds ratio, OR, 5.69) while antinuclear antibody positivity foretold less disability (OR 0.29). HLA-DR5 positivity conferred the greatest risk for pain (OR 3.34), while HLA-B5, DR3, and C3 were protective (OR 0.25, 0.28, 0.33, respectively). Early hand involvement was the strongest predictor of poorer overall well being (OR 8.75). Only the erythrocyte sedimentation rate was predictive of future QOL, but the model yielded a low C statistic (< 70%) and the OR 95% confidence limits were extreme (OR 9.77; 95% confidence interval, 1.22-77.8).

CONCLUSION

Clinical and immunogenetic variables measurable within 6 months of onset of JRA can be used to predict future disability, pain, and well being. QOL appears more difficult to forecast, perhaps due to the multiple domains that make up this outcome. Further study is needed to identify other genetic and laboratory factors that predict outcome in JRA with greater precision.

Inhibitory control as a contributor to conscience in childhood: from toddler to early school age

In this article we report a longitudinal extension of previous findings about the critical role of temperamental inhibitory or effortful control as the contributor to developing conscience in young children. A comprehensive observational battery, highly internally consistent, was developed to measure inhibitory control in 83 children at early school age who had been followed since toddlerhood and had been assessed using similar batteries at toddler and preschool age. We again confirmed the findings of robust longitudinal stability of inhibitory or effortful control, now from toddler to early school age, the increase with age, and gender differences, with girls outperforming boys. We also reaffirmed strong links, both contemporaneous and in the longitudinal sense, between inhibitory control and multiple, diverse measures of children's conscience at early school age, including observations of moral conduct, moral cognition, and moral self. The findings are discussed in view of the increasingly appreciated importance of temperament for critical aspects of socialization.

Dichloroacetate inhibits glutamine oxidation by decreasing pyruvate availability for transamination

We have shown that dichloroacetate (DCA) inhibits growth, glutamine oxidation, and pyruvate and alanine production in a concentration-dependent manner in PQXB 1/2 hybridoma cells. The use of inhibitors indicates that glutamine oxidation proceeds by an aminooxyacetate-sensitive transamination reaction in this cell line. Addition of pyruvate to DCA-treated cells restored glutamine oxidation to control values. Our data suggest that DCA inhibits glutamine oxidation by decreasing the availability of pyruvate for transamination, which in turn results in glutamate accumulation and a consequent inhibition of glutaminase activity. Impaired glutamine catabolism in the presence of DCA has subsequent effects on overall metabolic balance and cell maintenance and growth.

Mutated epitopes of hepatitis B surface antigen fused to the core antigen of the virus induce antibodies that react with the native surface antigen

Fusion of peptide epitopes to the core antigen (HBcAg) of hepatitis B virus (HBV) enhances their immunogenicity, both quantitatively and qualitatively. In a number of vaccine-induced mutants of HBV, glycine145 of the surface antigen S polypeptide (HBsAg) has been replaced by arginine, resulting in loss of cross-reactivity with antibodies to normal (wild-type) HBsAg. HBcAg fusion proteins carrying the immunodominant epitope of HBsAg, in which glycine145 was replaced by arginine, glutamic acid, or lysine, were produced in Escherichia coli and formed particles that displayed HBc antigenicity and immunogenicity similar to that of HBcAg itself. The fusion proteins also elicited T-cell proliferative responsiveness to HBcAg and HBsAg. Fusions carrying either wild-type or mutated epitopes of HBsAG showed HBs antigenicity in immunoblot analysis and antigen-capture immunoradiometric assay, but both mutant and wild-type derivatives induced antibodies that cross-reacted with wild-type HBsAG. The results emphasise the potential for HBcAg fusion proteins in vaccines by broadening the antibody response in a way that could confer protection against both wild-type and variant form of HBV.

Inadequacies in the Mental Health Act, 1983 in relation to mentally disordered remand prisoners

There are widely recognized problems regarding access to NHS facilities for mentally disordered remand prisoners (Robertson et al., 1994). The Bentham Unit was set up in February 1994 to provide the earliest possible hospital admission for mentally disordered remand prisoners. Over the first twelve months of the service's operation we assessed 150 and admitted 62 remand prisoners: a full description of the service is in preparation. Because admission is restricted to remand prisoners, the inadequacies of current legislation in allowing effective, uninterrupted care for remand transfers have become very apparent. There have been recent proposals to review the 1983 Mental Health Act (Murphy, 1995) and we suggest that provisions for assessment and treatment of mentally disordered remand prisoners should be revised in this context.

Expression of the adrenoleukodystrophy protein in the human and mouse central nervous system

The gene mutated in X-linked adrenoleukodystrophy (ALD), a progressive demyelinating disease, codes for a protein (ALDP) involved in very-long-chain fatty acid (VLCFA) transport. The expression of ALDP and of two peroxisomal enzymes involved in beta-oxidation of VLCFA, acyl-CoA oxidase, and catalase was studied in human and mouse brain. The pattern of expression was similar in both species. While acyl-CoA oxidase and catalase are found in all types of CNS cells, including neurons and oligodendrocytes, ALDP expression is restricted mostly to the white matter and endothelial cells. ALDP is highly expressed in astrocytes and microglial cells in vivo and in regenerating oligodendrocytes in vitro. In contrast, in vivo, ALDP is detected in much fewer oligodendrocytes and quantitative Western blot analysis confirmed the lower abundance of ALDP in these cells than in astrocytes. Only oligodendrocytes localized in corpus callosum, internal capsules, and anterior commissure express ALDP at levels comparable to those seen in astrocytes. In ALD, demyelination is first detected in these white matter regions, suggesting that the ALD gene mutation selectively affects those oligodendrocytes strongly expressing ALDP. Because of their failure to express ALDP, microglia and astrocytes may also contribute to demyelination in ALD patients.

Role of mitomycin in combination with fluorouracil and radiotherapy, and of salvage chemoradiation in the definitive nonsurgical treatment of epidermoid carcinoma of the anal canal: results of a phase III randomized intergroup study

PURPOSE

Definitive chemoradiation (CR) has replaced radical surgery as the preferred treatment of epidermoid carcinoma of the anal canal. To determine the importance of mitomycin (MMC) in the standard CR regimen and to assess the role of salvage CR in patients who have residual tumor following CR, a phase III randomized trial was undertaken by the Radiation Therapy Oncology Group (RTOG)/Eastern Cooperative Oncology Group (ECOG).

PATIENTS AND METHODS

Between August 1988 and December 1991, 310 patients were randomized to receive either radiotherapy (RT) and fluorouracil (5-FU) or radiotherapy, 5-FU, and MMC. Of 291 assessable patients, 145 received 45 to 50.4 Gy of pelvic RT plus 5-FU at 1,000 mg/m2/d for 4 days, and 146 received RT, 5-FU, and MMC (10 mg/m2 per dose for two doses). Patients with residual tumor on posttreatment biopsy were treated with a salvage regimen that consisted of additional pelvic RT (9 Gy), 5-FU, and cisplatin (100 mg/m2).

RESULTS

Posttreatment biopsies were positive in 15% of patients in the 5-FU arm versus 7.7% in the MMC arm (P = .135). At 4 years, colostomy rates were lower (9% v 22%; P = .002), colostomy-free survival higher (71% v 59%; P = .014), and disease-free survival higher (73% v 51%; P = .0003) in the MMC arm. A significant difference in overall survival has not been observed at 4 years. Toxicity was greater in the MMC arm (23% v 7% grade 4 and 5 toxicity; P < or = .001). Of 24 assessable patients who underwent salvage CR, 12 (50%) were rendered disease-free.

CONCLUSION

Despite greater toxicity, the use of MMC in a definitive CR regimen for anal cancer is justified, particularly in patients with large primary tumors. Salvage CR should be attempted in patients with residual disease following definitive CR before resorting to radical surgery.

Unrelated donor bone marrow transplantation to treat severe aplastic anaemia in children and young adults

Alternative donor bone marrow transplantation (BMT) to treat severe aplastic anaemia (SAA) in children and young adults has been complicated by high rates of graft rejection and severe graft-versus-host disease (GVHD). We hypothesized that increased immunosuppression combined with T-cell depletion of the marrow graft would enable successful use of unrelated donor BMT in this disease. Preconditioning consisted of cytosine arabinoside, cyclophosphamide, and total body irradiation (TBI). T-cell depletion was with the anti-CD3 antibody T10B9. GVHD prophylaxis consisted of cyclosporine A. 28 previously transfused patients were transplanted. Nine donor/recipient pairs were HLA matched. As of 1 January 1996, 15/28 (54%) patients are alive, transfusion independent and well with a range of follow-up of 13 months to 8 years (median 2.75 years). Fatalities include all three patients with nonengraftment and all three patients with grade III/IV GVHD. Other fatalities were due to infections or therapy-related toxicity. The incidence >or= grade II acute GVHD was 28%. These data show that in children with SAA who have failed immunosuppression, unrelated donor BMT offers a reasonable hope of long-term survival.

Identification of polyclonal serum specificities with phage-display libraries

A random hexapeptide fusion-phage library was screened to isolate phage that bound antibodies in a serum induced by hepatitis B virus surface antigen (HBsAg). Analysis of the isolated phage and comparison of their displayed peptide sequences with the primary sequence of HBsAg revealed areas where three and four amino acid matches accumulated. Differential binding studies of individual phage clones with immune and pre-immune sera identified phage carrying sequences that matched with region 117-122 of HBsAg which may represent a linear epitope or part of a larger antigenic determinant. Synthetic hexapeptides representing this region competed for binding with the matching phage clones.

Developmental and FGF-2-mediated regulation of syndecans (1-4) and glypican in oligodendrocytes

Differentiating cells undergo developmentally regulated changes in cell-cell and cell-matrix adhesion that control migration through microenvironments, proliferation, and differentiation. The diversity of the patterns of expression of heparan sulfate proteoglycans (HSPGs), coupled with their interactions with extracellular matrix, cell adhesion molecules, and growth factors, has emphasized their critical importance in the regulation of these events. Syndecans (1-4), glypican, and cerebroglycan are membrane-associated HSPGs that have been implicated in these events in various tissues and several tumor cell lines. We have examined the developmental expression and FGF-2-mediated regulation of these HSPGs during differentiation within a specific lineage of primary cells, oligodendrocytes (OL). Northern analyses of highly purified, developmentally synchronized populations of OL-lineage cells at three stages of differentiation (early and late progenitors and mature OLs) showed that the expression of individual forms of these syndecans and glypican are developmentally regulated. Specifically, the level of expression of syndecan-2 and -4 and glypican mRNAs increased as the cells differentiated from proliferative late progenitors to postmitotic mature cells. The expression of syndecan-1 and -3 had the inverse developmental pattern. Therefore, these two sets of molecules may have different roles in regulating the onset of terminal differentiation in OLs. The levels of mRNA expression were regulated by FGF-2: in late progenitors, FGF-2 induced a doubling of the mRNA levels of syndecan-2, -3, and -4, while those for syndecan-1 and glypican remained unaffected; in mature OLs, the levels of syndecan-1 mRNA were up-regulated, the levels of syndecan-2 and -4 and glypican were down-regulated. These results suggest that the individual syndecan molecules have distinct functions during the differentiation process and that multiple levels of regulation must exist, leading to a changing repertoire of these molecules during OL lineage progression and myelinogenesis.

Distal urethral duplication--a case report and literature review

Patient with partial duplication of the distal penile urethra ending blindly in the periurethral tissue, without an external meatus is reported. Relevant literature and the classification of urethral duplication is discussed.

Regulation of FGF receptors in the oligodendrocyte lineage

Fibroblast growth factors (FGFs) affect a broad spectrum of developmentally regulated cellular responses involved in the control of growth and differentiation. To identify specific FGF receptor forms involved in these responses, we have characterized FGF receptor transcript expression, and its modulation by FGF-2, as enriched populations of oligodendrocyte progenitors differentiate into mature oligodendrocytes. The data demonstrate that the levels of mRNA expression for FGF high-affinity receptors-1, -2, and -3 are differentially regulated during lineage progression: FGF receptor-1 expression increases with lineage progression, FGF receptor-2 is predominantly expressed by terminally differentiated oligodendrocytes, and FGF receptor-3 reaches a peak level of expression in late progenitors and then declines upon further differentiation; FGF receptor-4 expression was not detected in oligodendrocytes. Distinct patterns of alternatively spliced variants of FGF receptor-1 and -2 transcripts are expressed: the predominant FGF receptor-1 transcripts contain three Ig-like domains (FGF receptor-1 alpha), whereas the FGF receptor-2 transcripts contain two Ig-like domains (FGF receptor-2 beta 2) and this form is up-regulated as oligodendrocytes differentiate. In addition, the expression of these receptors is differentially regulated by the ligand, FGF-2: FGF receptor-1 mRNA expression is up-regulated in early progenitors, and FGF receptor-2 mRNA expression is down-regulated in mature oligodendrocytes. Finally, astrocytes express FGF receptor-1, -2, and -3 transcripts, but at different levels and with different exon utilization (FGF receptor-1 beta, FGF receptor-2 beta 1/beta 2) compared to oligodendrocytes. To our knowledge this is the first report that demonstrates that the mRNA expression of these three FGF receptor types is differentially regulated in primary cells as they differentiate along a lineage from progenitors to terminally differentiated cells. We propose that this pattern of expression provides a molecular basis for the developmentally varying response of cells to a common ligand. For example, according to this hypothesis, in response to FGF-2, FGF receptor-1 transduces signals that stimulate the prolonged proliferation and migration of early progenitors, FGF receptor-3 promotes the proliferation and arrest of differentiation of late progenitors, and FGF receptor-2 transduces signals for terminal differentiation, but not proliferation, in mature oligodendrocytes.

Inhibitory control in young children and its role in emerging internalization

We examined inhibitory control as a quality of temperament that contributes to internalization. Children were assessed twice, at 26-41 months (N = 103) and at 43-56 months (N = 99), on repeated occasions, in multiple observational contexts and using parental reports. Comprehensive behavioral batteries incorporating multiple tasks were designed to measure inhibitory control at toddler and preschool age. They had good internal consistencies, corresponded with maternal ratings, and were developmentally sensitive. Individual children's performance was significantly correlated across both assessments, indicating stable individual differences. Girls surpassed boys at both ages. Children's internalization was observed while they were alone with prohibited objects, with a mundane chore, playing games that occasioned cheating, being induced to violate standards of conduct, and assessed using maternal reports. Inhibitory control was significantly associated with internalization, both contemporaneously and as a predictor in the longitudinal sense. The implications for considering children's temperament as a significant, yet often neglected contributor to developing internalization are discussed.

Protein B: an important human IgA-binding reagent

Protein B had a much higher affinity for human IgA than Jacalin, increasing the sensitivity and specificity of the measurement of total human IgA. Protein B, used as a capturing agent, greatly enhanced the measurement of antigen-specific IgA as compared to alpha chain-specific antibodies.

IL-12, as an adjuvant, promotes a T helper 1 cell, but does not suppress a T helper 2 cell recall response

IL-12 is a potent inducer of NK and cytolytic T cell activity, IFN-gamma production, and T cell proliferation, and is necessary for differentiation of naive T cells to the Th1 subset. We have previously shown that IL-12 promotes a primary Th1 response and suppresses a primary Th2 response in lymph nodes of mice primed with a model hapten-protein conjugate, 2,4,6-trinitrophenyl (TNP)-keyhole limpet hemocyanin (KLH). We have now extended these studies to determine the Th phenotype of the recall response following immunization with soluble Ag and IL-12. For these experiments, mice were primed with TNP-KLH with or without treatment with IL-12, allowed to progress beyond the primary immune response, and challenged by i.p. injection of TNP-KLH. The phenotype of the recall response was monitored by measuring ex vivo production of IFN-gamma and IL-4 in Ag-stimulated lymph node and spleen cell cultures. Titer and isotype of TNP-specific serum Abs were also evaluated. Mice primed with Ag+IL-12 developed a Th1 recall response, as detected by KLH-specific IFN-gamma production from cultured spleen cells and the presence of TNP-specific IgG2a Ab in serum. However, they also developed an Ag-specific Th2 recall response, as characterized by Ag-induced IL-4 production from spleen cells and the presence of high titers of anti-TNP IgG1 in the serum. Studies of the cytokine profile during the primary response revealed that IL-12 induced in spleen cells the capacity to express both IL-4 and IFN-gamma. CD4+ T cells are necessary for production of IL-4 in the spleens of IL-12-treated mice, and most likely account for the Th2 recall response detected in mice primed with Ag+IL-12. These results indicate that the Th1 phenotype induced by immunization with IL-12 and Ag is maintained so that a Th1 recall response is expressed upon subsequent challenge with Ag. However, immunization with IL-12 also supports the development of a Th2 recall response, indicating that the Th1-inducing effect of IL-12 in vivo is not accompanied by a long lasting suppression of Th2 development.

IL-12, as an adjuvant, promotes a T helper 1 cell, but does not suppress a T helper 2 cell recall response

IL-12 is a potent inducer of NK and cytolytic T cell activity, IFN-gamma production, and T cell proliferation, and is necessary for differentiation of naive T cells to the Th1 subset. We have previously shown that IL-12 promotes a primary Th1 response and suppresses a primary Th2 response in lymph nodes of mice primed with a model hapten-protein conjugate, 2,4,6-trinitrophenyl (TNP)-keyhole limpet hemocyanin (KLH). We have now extended these studies to determine the Th phenotype of the recall response following immunization with soluble Ag and IL-12. For these experiments, mice were primed with TNP-KLH with or without treatment with IL-12, allowed to progress beyond the primary immune response, and challenged by i.p. injection of TNP-KLH. The phenotype of the recall response was monitored by measuring ex vivo production of IFN-gamma and IL-4 in Ag-stimulated lymph node and spleen cell cultures. Titer and isotype of TNP-specific serum Abs were also evaluated. Mice primed with Ag+IL-12 developed a Th1 recall response, as detected by KLH-specific IFN-gamma production from cultured spleen cells and the presence of TNP-specific IgG2a Ab in serum. However, they also developed an Ag-specific Th2 recall response, as characterized by Ag-induced IL-4 production from spleen cells and the presence of high titers of anti-TNP IgG1 in the serum. Studies of the cytokine profile during the primary response revealed that IL-12 induced in spleen cells the capacity to express both IL-4 and IFN-gamma. CD4+ T cells are necessary for production of IL-4 in the spleens of IL-12-treated mice, and most likely account for the Th2 recall response detected in mice primed with Ag+IL-12. These results indicate that the Th1 phenotype induced by immunization with IL-12 and Ag is maintained so that a Th1 recall response is expressed upon subsequent challenge with Ag. However, immunization with IL-12 also supports the development of a Th2 recall response, indicating that the Th1-inducing effect of IL-12 in vivo is not accompanied by a long lasting suppression of Th2 development.

Monoclonal autoantibody SCH94.03, which promotes central nervous system remyelination, recognizes an antigen on the surface of oligodendrocytes

A monoclonal antibody SCH94.03, made in syngeneic mice by injection of spinal cord homogenate, promotes central nervous system remyelination when injected into SJL/J mice chronically infected with Theiler's virus. To elucidate the mechanism of antibody-mediated remyelination, SCH94.03 was investigated by immunocytochemistry, flow cytometry, immunoelectron microscopy, Western blotting, and immuno-thin layer chromatography. All cell types investigated in vitro showed strong cytoplasmic staining with a pattern resembling a cytoskeletal protein. In contrast, among the primary cultured cells studied, only oligodendrocytes showed strong surface reactivity. Other cell types, including astrocytes, microglia, Schwann cells, myoblasts, and T and B lymphocytes, were negative. Mouse and rat oligodendrocytes which showed strong surface reactivity exhibited a well-differentiated morphology, and approximately 50% expressed myelin basic protein. Since oligodendrocyte progenitors were negative for surface staining, the expression of the antigens recognized by this monoclonal antibody appears to be developmentally regulated, i.e., transiently expressed on younger, terminally differentiating oligodendrocytes. Among the cell lines studied, only two rat oligodendrocyte lineage cell lines showed surface reactivity with SCH 94.03. Western blotting of secondary isolated oligodendrocytes lysates revealed reactivity with multiple protein bands of 27, 32, 50, 100, and 106 kDa, whereas there was no reactivity to lipid antigens by immuno-thin layer chromatography. These results raise the possibility that SCH94.03 recognizes a novel oligodendrocyte-specific surface antigen, and may act directly on oligodendrocytes to promote remyelination.

Preirradiation chemotherapy with cyclophosphamide, doxorubicin, vincristine, and dexamethasone for primary CNS lymphomas: initial report of radiation therapy oncology group protocol 88-06

PURPOSE

This study was a prospective phase I/II trial performed by the Radiation Therapy Oncology Group (RTOG) to test the tolerance and efficacy of preirradiation cyclophosphamide, doxorubicin, vincristine, and dexamethasone (CHOD) chemotherapy followed by large-volume, high-dose brain radiation therapy (RT) for patients with primary CNS lymphoma (PCNSL).

PATIENTS AND METHODS

Fifty-four (52 assessable) human immunodeficiency virus (HIV)-negative patients with PCNSL were entered on study and received two (n = 20) or three (n = 32) cycles of CHOD (six patients with positive CSF cytology received intrathecal methotrexate in addition to CHOD). Whole-brain RT to 41.4 Gy and tumor boost to 18 Gy (total dose, 59.4 Gy) followed chemotherapy.

RESULTS

As of July 1994, with a minimum potential follow-up time of 20 months, 12 of 52 assessable patients remain alive without evidence of progression. The median survival time for the entire group is 16.1 months, with a 2-year survival rate of 42%. By univariate analysis, patient age was found to be a significant prognostic factor with respect to survival (P = .005) in favor of age less than 60 years. Karnofsky performance status (KPS) was of borderline significance (P = .057). Survival for patients treated on RTOG 88-06 was compared with that of patients treated on RTOG 83-15, which tested RT alone. No difference in overall survival was found (P = .53). Grade 4 neutropenia developed in 29 of 51 patients during chemotherapy. There were two deaths during chemotherapy: one as a result of sepsis and one of a pulmonary embolus. The worst toxicity during RT was < or = grade 2 in 50 of 52 patients.

CONCLUSION

Preirradiation CHOD chemotherapy does not significantly improve survival over RT alone for patients with PCNSL. Age remains a powerful prognostic factor independent of therapy and must be considered in testing alternative combined approaches.

Ureteral triplication, occasionally an isolated anomaly

A case of isolated ureteral triplication is presented, the patient did not have any other urogenital anomaly. This presentation is rare and relevant literature is discussed.

A complex cystic dysplastic urogenital anomaly--an odd presentation

We report a case of an ectopic ureter opening into a distorted cystic seminal vesicle, with ipsilateral renal aplasia and an unusual presentation. Literature relevant to its embryology and management is discussed.

Comparison of bone contusion seen by MRI in partial and complete tears of the anterior cruciate ligament

OBJECTIVE

Bone contusions are frequently found in association with complete tears of the anterior cruciate ligament (ACL) and can be a helpful secondary sign in diagnosis. We compare the frequency, location, and significance of bone contusions in complete and partial ACL tears.

MATERIALS AND METHODS

Twenty-nine patients with complete and 42 patients with incomplete tears of the ACL were examined by MRI for the presence of accompanying bone contusions within 1 month of injury.

RESULTS

Bone contusions were found in 72% of the complete ACL tears but in only 12% of the partial tears. Of the partial ACL tears with accompanying contusions, 80% were high grade injuries that eventually went on to complete rupture within 6 months. Only 16% of the partial ACL injuries without bone contusion progressed to complete rupture at 1-2 year follow-up. There was no difference between the bone contusions of partial and complete tears in terms of general appearance and location. They were predominantly in the lateral compartment (90%) and had a specific predilection for the mid portion of the lateral femoral condyle and the posterior portion of the lateral tibial plateau, often occurring in tandem.

CONCLUSION

Bone contusions occur with much less frequency in partial ACL tears than in complete tears but their presence in partial rupture favors a high grade tear that is likely to become complete.

Scottish neonatal intensive care units; a study of staff and parental attitudes

The study takes a three stage approach to review Scottish unit policies, staff views and parents experiences of visiting and involvement with their low birthweight infant (1,750 gm or less) in a sample of Scottish neonatal intensive care units (NICUs). The study indicated that while most units had 'liberal' views regarding parental and family visiting some staff views were not in line with their unit policy and retained reservations about family visiting. Many parents reported visiting daily despite considerable 'social' and real costs. Unit differences emerged regarding the degree of parental involvement as measured by tasks carried out.

Patterns of T lymphocyte clonal expansion in HLA-typed patients with juvenile rheumatoid arthritis

OBJECTIVE

The presence of clonally expanded T lymphocytes appears to be a characteristic feature of autoimmune diseases, including juvenile rheumatoid arthritis (JRA), although the relevance of such clones to immunopathogenesis is not clear. Identification of clones specific for a disease and/or particular MHC haplotypes should help differentiate those of pathogenic importance.

METHODS

A reverse transcriptase polymerase chain reaction assay for T cell receptor (TCR) complementarity determining region 3 (CDR3) length heterogeneity and cDNA sequencing were used to identify clonal expansion in synovial fluid (SF) samples obtained from 36 patients with JRA.

RESULTS

The majority of patients had multiple synovial T cell clones using different TCR V beta families. Fifty-eight percent of these clonally expanded T cell populations used one of six TCR V beta families (V beta 2, V beta 8, V beta 14, V beta 16, V beta 17, and V beta 20). Patients with polyarticular, as opposed to pauciarticular, JRA had higher numbers of clones in joints. TCR V beta 8, V beta 14, V beta 16, and V beta 17 families were most frequently found in these clones. Overall, the most frequently used V beta family was V beta 20, which was observed in 18 of 36 SF samples. Of 18 patients exhibiting TCR V beta 20 clonal expansion, 14 (78%) had pauciarticular onset JRA. The V beta 20 association was especially strong in patients who possessed HLA-DR8+ haplotypes (p = 0.01, Fisher's exact test). SF from the patients who had other types of JRA (and other MHC haplotypes) did not show this association.

CONCLUSION

The distinct clinical subtypes of JRA are characterized by different patterns of synovial T cell clonality. These findings imply that different molecular pathways underlie the development of arthritis in each subtype of JRA.

Infection of humans and horses by a newly described morbillivirus

OBJECTIVE

To describe the clinical and epidemiological features of an outbreak of a viral infection affecting humans and horses.

SETTING

Stables in Hendra, a suburb of Brisbane.

SUBJECTS

Affected horses and humans, and at-risk human contacts.

RESULTS

A pregnant mare died two days after arrival from a paddock elsewhere in Brisbane. Eight to 11 days later, illness (depression, anorexia, fever, dyspnoea, ataxia, tachycardia, tachypnoea and nasal discharge) was reported among 17 other horses from the same or an adjoining stable. Fourteen horses died or were put down. Five and six days after the index mare's death, a stable-hand and then a horse-trainer, both of whom had had close contact with the sick mare's mucous secretions, developed influenza-like illnesses. The stable-hand recovered but the trainer developed pneumonitis, respiratory failure, renal failure and arterial thrombosis, and died from a cardiac arrest seven days after admission to hospital. A morbillivirus cultured from his kidney was identical to one isolated from the lungs of five affected horses. The two affected humans and eight other horses were seropositive for the infection, which was reproduced in healthy horses following challenge by spleen/lung homogenates from infected horses. There was no serological evidence of infection in 157 humans who had had contact with the stables or the sick horses or humans.

CONCLUSIONS

A previously undescribed morbillivirus infected a probable 21 horses and two humans; one human and 14 horses died. That no further cases were detected among humans suggests that the virus was of low infectivity. The source of infection remains undetermined.

Mutations of some critical amino acid residues in the hepatitis B virus surface antigen

Amino acid substitutions at several positions in the surface antigen (HBsAg) of hepatitis B virus (HBV) in natural isolates and the products of recombinant DNA molecules have identified important residues for cross-reaction with specific antibodies (anti-HBs) and the induction of antibodies with certain serological specificities. In a further group of mutants described here, cysteine residues in a region believed to be significant of the a epitope have been changed to serines. Of the three adjacent cysteine residues at positions 137, 138 and 139, mutation of either of the flanking residues reduced cross-reactivity with polyclonal anti-HBs, while alteration of the central residue was relatively well-tolerated. Mutation of cysteine 149 to serine or of glycine 145 to arginine (imitating naturally occurring mutants), lysine, or glutamatic acid all led to loss of cross-reactivity with polyclonal antisera.

Direct measurement via phage titre of the dissociation constants in solution of fusion phage-substrate complexes

Studies of interactions between filamentous fusion phage particles and protein or nucleic acid molecules have gained increasing importance with recent successes of screening techniques based upon random phage display libraries (biopanning). Since a number of different phage are usually obtained by biopanning, it is useful to compare quantitatively the binding affinities of individual phage for the substrate used for selection. A procedure is described for determination of relative dissociation constants (KdRel) between filamentous phage carrying peptide fusions to the coat protein gpIII and substrates in solution. This novel method is based on the measurement of phage titres. Phage selected from a random fusion phage library for binding to a monoclonal antibody or a viral structural protein exhibited KdRel values in the nanomolar and micromolar ranges for their respective substrates, thus validating the method over a wide range of binding affinities.

Unrelated bone marrow donor transplants for children with leukemia or myelodysplasia

Allogeneic bone marrow transplantation is the treatment of choice for many childhood leukemias. The donor of choice-an HLA matched sibling-is only available about 30% of the time. Unrelated donors are an alternative choice. In this report, we describe the results of unrelated donor bone marrow transplants (BMT) in 50 children with leukemia (25 acute lymphoblastic leukemia [ALL], 3 acute myeloid leukemia [AML], 3 juvenile chronic myelogenous leukemia [JCML], 10 chronic myeloid leukemia [CML]) or myelodysplastic syndrome (MDS; 9). The median age of the 31 male and 19 female patients was 9 years (range 2 to 18). Only 13 patients were serologically matched at HLA-A, B, DR, and DQ with their donors; 6 of these were reactive in mixed lymphocyte culture. The other 37 patients were mismatched for one (36 patients) or more (1 patient) HLA antigens. Pretransplant conditioning included cytosine arabinoside, cyclophosphamide, fractionated total body irradiation (TBI) (with lung, liver, and more recently, kidney shielding), and methylprednisolone. High-risk patients also received busulfan. Graft-versus-host disease (GVHD) prophylaxis consisted of T-cell depletion with IgM monoclonal antibody T10B9 plus complement and posttransplant cyclosporine-A. Forty-nine patients (98%) engrafted. Median times to greater than 500 polymorphonuclear leukocytes (PMN)/microL and greater than 25,000 platelets/microL were 18 and 20 days, respectively. Acute GVHD > or = grade II occurred in 16 patients (33%); 13 (81%) of these died. Chronic GVHD developed in 30 of 40 patients at risk, but was extensive in only 5. Event-free survival (EFS) for all patients was 44% +/- 7% (median follow-up was 49 months), and overall survival was 50 +/- 7%. Patients with low-risk disease (ALL or AML in first or second remission and CML in chronic phase) had a better EFS than children with high-risk disease (60% v 34%, P = .07). There was no significant difference in EFS between patients who were serologically matched with their donors (46%) and those who were partially mismatched (43%) (P = .97). These data compare favorably with published reports for children transplanted with HLA-matched sibling donors and should encourage earlier consideration of unrelated donor BMT in children with leukemia or myelodysplasia.

A morbillivirus that caused fatal disease in horses and humans

A morbillivirus has been isolated and added to an increasing list of emerging viral diseases. This virus caused an outbreak of fatal respiratory disease in horses and humans. Genetic analyses show it to be only distantly related to the classic morbilliviruses rinderpest, measles, and canine distemper. When seen by electron microscopy, viruses had 10- and 18-nanometer surface projections that gave them a "double-fringed" appearance. The virus induced syncytia that developed in the endothelium of blood vessels, particularly the lungs.

Selection of peptide inhibitors of interactions involved in complex protein assemblies: association of the core and surface antigens of hepatitis B virus

As an example for studies of contacts involved in complex biological systems, peptide ligands that bind to the core antigen of hepatitis B virus (HBcAg) have been selected from a random hexapeptide library displayed on filamentous phage. Affinity-purified phage bearing aa sequence LLGRMK, or some related sequences, bound full-length or truncated HBcAg but did not bind denatured HBcAg. The long (L), but not the short (S), hepatitis B virus envelope polypeptide, when synthesized in an in vitro system, bound firmly to HBcAg, indicating that interaction between HBcAg and the pre-S region of the L polypeptide is critical for virus morphogenesis. This interaction was inhibited by peptide ALLGRMKG, suggesting that this and related small molecules may inhibit viral assembly.

Malignant change in enterocystoplasty: a histochemical assessment

Increasing numbers of cases of malignant tumours occurring in enterocystoplasties are being reported. Material from five cases of adenocarcinoma arising in such patients were studied using standard mucin and carbohydrate lectin staining methods. Sections from the tumour and adjacent and distant mucosa were stained to determine the pattern of histochemical changes. The abnormal staining patterns seen suggest that the adenocarcinomata arising at the enterovesical anastomosis are of intestinal origin. A hypothesis is advanced to explain the pathogenesis of these tumours.