Neuregulin in neuron/glial interactions in the central nervous system. GGF2 diminishes autoimmune demyelination, promotes oligodendrocyte progenitor expansion, and enhances remyelination

Glial growth factor 2 (GGF2) is a neuronal signal that promotes the proliferation and survival of the oligodendrocyte, the myelinating cell of the central nervous system (CNS). This study has focused on recombinant human GGF2 (rhGGF2) and it's potential to affect clinical recovery and repair to damaged myelin in chronic relapsing experimental autoimmune encephalomyelitis (EAE) in the mouse, a major animal model for the human demyelinating disease, multiple sclerosis (MS). Mice with EAE were treated with rhGGF2 during both the acute and relapsing phases, and GGF2 treatment led to delayed signs, decreased severity and resulted in statistically significant reductions in relapse rate. Further, rhGGF2-treated groups displayed CNS lesions with more remyelination than in controls. This correlated with increased expression of myelin basic protein exon 2, a marker for remyelination, and with an increase of the regulatory cytokine, IL-10. Thus, a beneficial effect of a neurotrophic growth factor has been demonstrated upon the clinical, pathologic and molecular manifestations of autoimmune demyelination, an effect that was associated with increased expression of a Th2 cytokine. rhGGF2 treatment may represent a novel approach to the treatment of MS (Cannella et al., 1998).

Data mining parasite genomes: haystack searching with a computer

A number of genomes of parasitic organisms are presently being sequenced in the public domain, including Plasmodium falciparum, Leishmania major and Trypanosoma brucei with the likelihood of at least expressed sequence tag (EST) projects for several filarial and apicomplexan species. The early and timely release of sequence data to the community via the World Wide Web (www), and the public databases, (EMBL and GENBANK), forms an invaluable resource. Data mining, or 'haystack searching' this resource is becoming more fruitful to all members of the scientific community as the volume of data, diversity of genomes sampled, and accessibility increase.

The complete nucleotide sequence of chromosome 3 of Plasmodium falciparum

Analysis of Plasmodium falciparum chromosome 3, and comparison with chromosome 2, highlights novel features of chromosome organization and gene structure. The sub-telomeric regions of chromosome 3 show a conserved order of features, including repetitive DNA sequences, members of multigene families involved in pathogenesis and antigenic variation, a number of conserved pseudogenes, and several genes of unknown function. A putative centromere has been identified that has a core region of about 2 kilobases with an extremely high (adenine + thymidine) composition and arrays of tandem repeats. We have predicted 215 protein-coding genes and two transfer RNA genes in the 1,060,106-base-pair chromosome sequence. The predicted protein-coding genes can be divided into three main classes: 52.6% are not spliced, 45.1% have a large exon with short additional 5' or 3' exons, and 2.3% have a multiple exon structure more typical of higher eukaryotes.

Schwann cell-derived Desert hedgehog controls the development of peripheral nerve sheaths

We show that Schwann cell-derived Desert hedgehog (Dhh) signals the formation of the connective tissue sheath around peripheral nerves. mRNAs for dhh and its receptor patched (ptc) are expressed in Schwann cells and perineural mesenchyme, respectively. In dhh-/- mice, epineurial collagen is reduced, while the perineurium is thin and disorganized, has patchy basal lamina, and fails to express connexin 43. Perineurial tight junctions are abnormal and allow the passage of proteins and neutrophils. In nerve fibroblasts, Dhh upregulates ptc and hedgehog-interacting protein (hip). These experiments reveal a novel developmental signaling pathway between glia and mesenchymal connective tissue and demonstrate its molecular identity in peripheral nerve. They also show that Schwann cell-derived signals can act as important regulators of nerve development.

Do patients' ethnic and social factors influence the use of do-not-resuscitate orders?

OBJECTIVES

To determine whether ethnic and other social factors affect how frequently do-not-resuscitate (DNR) orders are written, the timing of DNR orders, or patient involvement in the DNR decision.

DESIGN

Retrospective cohort.

METHODS

Patients who died in one urban teaching hospital on the medicine, cardiology, or family practice service during 1988 were eligible; 288 were included in the analyses. Chi-square tests and logistic regression were used to examine frequency of DNR orders and patient involvement; analysis of variance and linear regression were used to examine timing of the DNR orders.

RESULTS

Non-whites were more likely than whites to have DNR orders (OR 1.76; 95% CI, 1.09-2.84) but timing of the DNR order did not vary significantly by race/ethnicity. Patients who spoke English fluently were more likely to be involved in the DNR decision than those who did not (OR 1.28; 95% CI, 1.01-1.61). Patients with documented human immunodeficiency virus were more likely than uninfected patients to have DNR orders (OR 3.51; 95% CI, 1.36-9.02), to be involved in the decision (OR 10.11; 95% CI, 4.87-21.00); and to have DNR orders written earlier (P = 0.02). Alcoholic patients were more likely than non-alcoholics to have DNR orders (OR 1.17; 95% CI, 1.04-1.33).

CONCLUSIONS

Ethnic and other social factors do appear to play a role in DNR decisions. It needs to be determined if these differences are due to patient preferences or clinician characteristics.

Epidermal growth factor receptor activation is localized within low-buoyant density, non-caveolar membrane domains

Increasing evidence for the organization of cell-surface proteins and lipids into different detergent-insoluble rafts led us to investigate epidermal growth factor (EGF) receptor activation in the plasma membranes of A431 carcinoma cells, using a combination of cell fractionation and immunoprecipitation techniques. Density-gradient centrifugation of sodium carbonate cell extracts revealed that the vast majority of both stimulated and unstimulated EGF receptors were concentrated in a caveolin-rich light membrane (CLM) fraction, with the biochemical characteristics of detergent-insoluble glycolipid-rich domains (DIGs). However, ultrastructural analysis of the CLM fraction revealed that it contained a heterogeneous collection of vesicles, some with sizes greater than that expected for individual caveolae. Experiments with detergent-solubilized cells and isolated CLMs indicated that, in contrast with caveolin, EGF receptors were unlikely to be localized to DIG domains. Furthermore, immunoisolation of caveolin from CLMs revealed that EGF receptor activation occurs in a compartment distinct from caveolae. Similarly, using an anti-(EGF receptor) antibody, the bulk of the cellular caveolin was not co-immunoprecipitated from CLMs, thereby confirming that these two proteins reside in separate membrane domains. The deduction that caveolar signalling and EGF receptor activation occur in separable rafts argues for a multiplicity of signal transduction compartments within the plasma membrane. In addition, by demonstrating that EGF receptor activation is compartmentalized within low-density, non-caveolar regions of the plasma membrane, it is also shown that the co-localization of proteins in a CLM fraction is insufficient to prove caveolar localization.

Sex and androgenic steroid receptor expression in hepatic adenomas

Sex hormones and anabolic-androgenic steroids are implicated in the development and progression of hepatic adenomas (HA). We studied the expression of their receptors in HA and adjacent liver. Archival tissue sections of 27 HA (16 resections, four needle biopsies, seven aspirations) from 18 patients, and the adjacent liver, were immunostained with monoclonal antibody to estrogen receptor (ER, 1/80) (Dako, Carpinteria, CA), progesterone receptor (PR, 1/50) (BioGenex, San Ramon, CA), and androgen receptor (AR, 1/80) (BioGenex). An avidin-biotin complex technique was used with microwave antigen retrieval. Nuclear expression was assessed as 1+ to 3+ intensity, with semiquantitation of the percentage of nuclei immunopositive. Five percent or more nuclei immunopositive was regarded as positive. The 18 patients included 16 females of 34 years mean age (range, 16 to 49) with an available history of oral contraceptives in five; the two men were 24 and 30 years, with no history of androgenic steroids. ER, PR, and AR were present in seven (26%) (1+/-2+ intensity, 5% to 10% of nuclei) of HA, seven (26%) (1+/-2+ intensity, 5% to 30% of nuclei) and nine (33%) (1+/-3+ intensity, 5% to 80% of nuclei), respectively. In the adjacent liver in 11 cases, there were one (9%) ER, (2+ intensity, 5% of nuclei), four (36%) PR (1+/-2+ intensity, 5% to 20% of nuclei), and two (18%) AR (2+/-3+ intensity, 10% of nuclei). Receptors are present and may mediate the action of sex hormones or androgenic steroids on HA and adjacent liver, but in less than one third of patients. This may have therapeutic implications.

A long-range restriction map across 3 Mb of the chromosome 11 breakpoint region of a translocation linked to schizophrenia: localization of the breakpoint and the search for neighbouring genes

A balanced t(1;11)(q42.1;q14.3) translocation segregates with schizophrenia and related mental illness in a single large Scottish pedigree. We have constructed a long-range restriction map covering at least 3 Mb of the chromosome 11 breakpoint region and conducted searches for genes whose expression could be altered by the translocation, resulting in schizophrenia. Novel transcribed sequences of unknown function clustered around putative CpG islands, located approximately 500 kb and 700 kb above the breakpoint, represent the only evidence to date for expressed genes within the mapped region.

The neuregulin, glial growth factor 2, diminishes autoimmune demyelination and enhances remyelination in a chronic relapsing model for multiple sclerosis

Glial growth factor 2 (GGF2) is a neuronal signal that promotes the proliferation and survival of the oligodendrocyte, the myelinating cell of the central nervous system (CNS). The present study examined whether recombinant human GGF2 (rhGGF2) could effect clinical recovery and repair to damaged myelin in chronic relapsing experimental autoimmune encephalomyelitis (EAE) in the mouse, a major animal model for the human demyelinating disease, multiple sclerosis. Mice with EAE were treated with rhGGF2 during both the acute and relapsing phases. Clinically, GGF2 treatment delayed signs, decreased severity, and resulted in statistically significant reductions in relapse rate. rhGGF2-treated groups displayed CNS lesions with more remyelination than in controls. This correlated with increased mRNA expression of myelin basic protein exon 2, a marker for remyelination, and with an increase in the CNS of the regulatory cytokine, interleukin 10, at both the RNA and protein levels. Thus, a beneficial effect of a neurotrophic growth factor has been demonstrated on the clinical, pathologic, and molecular manifestations of autoimmune demyelination, an effect that was associated with increased expression of a T helper 2 cytokine. rhGGF2 treatment may represent a novel approach to the treatment of multiple sclerosis.

Phosphatidylinositol 4-phosphate synthesis in immunoisolated caveolae-like vesicles and low buoyant density non-caveolar membranes

This study examined phosphatidylinositol 4-phosphate (PtdIns4P) synthesis in caveolae that have been suggested to be discrete signaling microdomains of the plasma membrane and are enriched in the marker protein caveolin. Caveolin-rich light membranes (CLMs) were isolated from A431 cells by detergent-free, discontinuous density-gradient centrifugation method. The CLM fraction was separated from the bulk of the cellular protein and was greatly enriched in PtdIns, PtdIns4P, and phosphatidylinositol 4, 5-bisphosphate (PtdIns(4,5)P2) and an adenosine-sensitive type II PtdIns 4-kinase activity. Preparation of CLMs by an OptiPrep-based cell fractionation procedure confirmed the co-localization of PtdIns 4-kinase and caveolin. Electron microscopy confirmed that an anti-caveolin antiserum immunopurified vesicles from CLMs that were within the size range described for caveolae in other systems. Co-immunoprecipitated PtdIns 4-kinase activity could utilize endogenous PtdIns, present within the caveolae-like vesicles, to produce PtdIns4P. The addition of recombinant phosphatidylinositol transfer protein increased PtdIns 4-kinase activity both in immunoisolated caveolae and CLMs. However, less than 1% of the total cellular PtdIns and PtdIns 4-kinase activity was present in caveolae-like vesicles, indicating that non-caveolar light membrane rafts are the main site for cellular PtdIns4P production.

Immediate breast reconstruction for stage III breast cancer using transverse rectus abdominis musculocutaneous (TRAM) flap

BACKGROUND

The management of state III breast cancer is challenging; it often includes multimodal treatment with systemic therapy and/or radiation therapy and surgery. Immediate breast reconstruction has not traditionally been performed in these patients. We review the results of immediate transverse rectus abdominis musculocutaneous (TRAM) flap in 21 patients treated for stage III breast cancer.

METHODS

Data have been collected retrospectively on 21 patients diagnosed with stage III breast cancer between 1987 and 1994. All patients had mastectomy and immediate TRAM reconstruction. Thirteen patients received primary systemic therapy, 10 patients received postoperative consolidation radiotherapy to the operative site, and 3 patients received preoperative radiation.

RESULTS

Mean follow-up for the group was 26 months. Two patients died with disseminated disease: neither of them developed local disease recurrence in the operative site; 82% of the patients followed for at least two years are free of disease. Sixty-two percent of the patients received preoperative chemotherapy, the remaining patients received postoperative multiagent chemotherapy and/or radiation therapy. Two of the patients received autologous bone marrow transplants after their adjuvant therapy. Ten patients had postoperative radiotherapy for consolidation; three patients received preoperative radiation.

CONCLUSIONS

Immediate TRAM reconstruction for stage III breast cancer is not associated with a delay in adjuvant therapy or an increased risk of local relapse. It facilitates wide resection of involved skin without skin grafting. Radiation therapy can be delivered to the reconstructed breast when indicated without difficulty. Breast reconstruction facilitates surgical resection of stage III breast cancer with primary closure and should be considered if the patient desires immediate breast reconstruction.

Characterization of a chromosome-specific chimpanzee alpha satellite subset: evolutionary relationship to subsets on human chromosomes

Alpha satellite DNA is a tandemly repeated DNA family found at the centromeres of all primate chromosomes examined. The fundamental repeat units of alpha satellite DNA are diverged 169- and 172-bp monomers, often found to be organized in chromosome-specific higher-order repeat units. The chromosomes of human (Homo sapiens (HSA)), chimpanzee (Pan troglodytes (PTR) and Pan paniscus), and gorilla (Gorilla gorilla) share a remarkable similarity and synteny. It is of interest to ask if alpha satellite arrays at centromeres of homologous chromosomes between these species are closely related (evolving in an orthologous manner) or if the evolutionary processes that homogenize and spread these arrays within and between chromosomes result in nonorthologous evolution of arrays. By using PCR primers specific for human chromosome 17-specific alpha satellite DNA, we have amplified, cloned, and characterized a chromosome-specific subset from the PTR chimpanzee genome. Hybridization both on Southern blots and in situ as well as sequence analysis show that this subset is most closely related, as expected, to sequences on HSA 17. However, in situ hybridization reveals that this subset is not found on the homologous chromosome in chimpanzee (PTR 19), but instead on PTR 12, which is homologous to HSA 2p.

Rapid bright-field detection of oligonucleotide primed in situ (PRINS)-labeled DNA in chromosome preparations and frozen tissue sections

We describe a new application of a bright-field microscopic procedure for rapid enzyme cytochemical detection of repeated DNA sequences in metaphase preparations and frozen tissue sections. Various chromosome-specific oligonucleotide primers were used in up to three sequential primed in situ (PRINS) labeling reactions together with Taq DNA polymerase and biotin, digoxigenin and/or fluorescein isothiocyanate (FITC)-modified nucleotides. DNA target sequences were localized simultaneously by the precipitates of the horseradish peroxidase-diaminobenzidine (PO-DAB, brown color), alkaline phosphatase-Fast Red (APase-Fast Red, red color) and horseradish peroxidase-teramethylbenzidine (PO-TMB, green color) reaction in hematoxylin counterstained metaphases and interphase nuclei using a standard bright-field microscope. In addition, a protocol is reported for the application of PRINS to frozen tissue sections from normal colon and bladder epithelium. Methanol/acetic acid fixation in combination with a pepsin digestion before performing the PRINS reaction proved to be critical steps in the total procedure that permits access of the PRINS reactants, while preserving the morphology of the nuclei in the tissue. Quantification of PRINS signals showed the majority of epithelial cells with the expected two chromosome copies. The described procedures can be considered valuable tools for application in molecular cytogenetics, cell biology and pathology.

Human repeat-mediated integration of selectable markers into somatic cell hybrids

We describe a strategy to introduce preferentially the dominant selectable marker neoR into the human chromosome within a monochromosome hybrid cell line. Integration of a construct containing the marker is mediated by human-specific repeat elements that promote multilocus human-specific integration with a single targeting vector. We tested two classes of repeat elements: the Alu family of SINE repeats and the Line1 repeat family. We show that Alu sequences alone are insufficient to direct human-specific integration but when used in combination with a Line1 element, or when only Line1 elements are included, integration of the vector into the human component of a monochromosome somatic cell hybrid is favored. The vectors also carry sequences that facilitate mapping and selective cloning of the targeted region. This strategy provides a means to generate selectable human subchromosomal fragments that can be used for localization of genes through positional cloning and, more important, for the identification of functional units through DNA transfer.

Power spectrum of the fast Fourier transform for measurement of standing balance

Power spectrum of the force moment generated from the fast Fourier transform (FFT) was utilised to evaluate standing balance on a force platform. The principles on generating and analysing an FFT spectrum from the output of the force platform are illustrated. Test-retest reliability of twelve healthy young people (age = 26 +/- 4 years) was performed with the preferred leg stance. The intraclass correlation coefficient (ICC), R, of mean power (P), spectral area (Sx) and maximum power (Px) were 0.89, 0.85 and 0.89 respectively, indicating that the spectral parameters are reliable quantitative measures of balance. Pearson product moment (PPM), r, of these spectral parameters were 0.95, 0.85 and 0.95 respectively showing that these spectral parameters are significantly correlated (p < 0.01). A comparison was made with respect to the one legged stance and two legged stance steadiness. The one legged stance (Sx = 95.75 cm.Hz) was significantly less stable than the two legged stance (Sx = 41.58 cm.Hz) with a value of 9.37. Moreover, the one legged stance was highly correlated to the two legged stance (r = 0.84), indicating that, in general, a subject who has a stable one legged stance should have a stable two legged stance.

Rupture of the peroneus longus tendon

The authors report a case of fracture of the os peroneum with diastasis in a 34-year-old woman. This represents one of the few cases of this type of fracture to be reported in the literature. This injury must be included in the differential diagnosis of a sprained ankle, and only careful examination of serial roentgenograms can prevent an incorrect diagnosis.

Is myosin a "back door" enzyme?

ATP has been modeled into the active site of chicken skeletal myosin subfragment-1 using the adenylate kinase.Ap5A structure as a starting reference. The resulting docked ATP.S1 structure is justified in that it rationalizes the photolabeling data from several ATP analogs. The gamma-phosphate of ATP sits at the bottom of the active site pocket and is partially visible via a view along the prominent 50-kDa cleft of S1 but not when viewed from above the active site. It is postulated that actin binding promotes the movement of the P-loop and Arg-245 to allow Pi from ATP to leave via a "back-door" in the 50-kDa fragment while ADP is still bound at the active site. Such a mechanism can explain a number of experimental observations, including the kinetics of ATP hydrolysis, the nucleotide dependence of Pi exchange into ATP, and the formation of stable myosin.ADP.vanadate complexes in muscle fibers.

Prophylactic aspirin and risk of peptic ulcer bleeding

OBJECTIVE

To determine the risks of hospitalisation for bleeding peptic ulcer with the current prophylactic aspirin regimens of 300 mg daily or less.

DESIGN

A case-control study with hospital and community controls.

SETTING

Hospitals in Glasgow, Newcastle, Nottingham, Oxford, and Portsmouth.

SUBJECTS

1121 patients with gastric or duodenal ulcer bleeding matched with hospital and community controls.

RESULTS

144 (12.8%) cases had been regular users of aspirin (taken at least five days a week for at least the previous month) compared with 101 (9.0%) hospital and 77 (7.8%) community controls. Odds ratios were raised for all doses of aspirin taken, whether compared with hospital or community controls (compared with combined controls: 75 mg, 2.3 (95% confidence interval 1.2 to 4.4); 150 mg, 3.2 (1.7 to 6.5); 300 mg, 3.9 (2.5 to 6.3)). Results were not explained by confounding influences of age, sex, prior ulcer history or dyspepsia, or concurrent non-aspirin non-steroidal anti-inflammatory drug use. Risks seemed particularly high in patients who took non-aspirin non-steroidal anti-inflammatory drugs concurrently.

CONCLUSION

No conventionally used prophylactic aspirin regimen seems free of the risk of peptic ulcer complications.

Actin, its associated proteins and metastasis

In this short article we have overviewed the effect of transformation on AAPs. We have not dealt with molecules indirectly associated with actin which are modified by transformation, such as the catenins, cadherins, vinculin, and integrins [Tsukita et al., 1993], although their relationship with and importance to the transformed phenotype cannot be overemphasised. Similarly, alterations in polyphosphoinositide metabolism that occur in transformed cells may also promote or induce alterations in the microfilament cytoskeleton via interactions with proteins such as gelsolin, alpha-actinin, and MARCKS [Bretscher, 1993]. At present, there are no clear-cut rules regarding the effect that oncogenesis has on AAPs, since the expression level of one oncogenically modified AAP can vary from one tumour to another, even within the same type of tumour [Yamamoto et al., 1993]. This apparent inconsistency may well be because we are "playing with an incomplete pack of cards" [Pollard, 1993], or it may reflect this highly complex control mechanism in which any perturbation of the normal expression levels of actin/AAPs unbalances the delicate equilibrium which controls normal cell behaviour [Bray and Vasiliev, 1989]. For example, it is possible that oncogenically induced alterations to actin isoform expression [Lin et al., 1985] exert a downstream effect on actin-associated protein expression. Oncogenically induced actin based cell movements may be activated by alterations to either a single AAP or a synergistic functional unit of these molecules [Shapland et al., 1993; Vandekerckhove et al., 1990].(ABSTRACT TRUNCATED AT 250 WORDS)

Instant PRINS: a rapid method for chromosome identification by detecting repeated sequences in situ

We describe a method for labeling specific chromosomes in situ by oligonucleotide-primed synthesis and incorporation of fluorochrome-labeled dUTP, together with an accelerated protocol for the reaction. The combination of the two developments produces extremely rapid results, in some cases taking less than 5 min for the complete process. The significance of this development for clinical diagnosis is discussed.

Multi-PRINS: multiple sequential oligonucleotide primed in situ DNA synthesis reactions label specific chromosomes and produce bands

A fast method for identifying several chromosomes with chromosome-specific oligonucleotide primers directing an in situ labeling reaction is described. Up to three reactions distinguished by different fluorochromes (fluorescein isothiocyanate, rhodamine/Texas red, p-amino-methyl-cyclohexane carboxylic acid) can currently be performed. Prospects for increasing this up to seven colors, and for the future of the process in prenatal diagnosis are discussed.

Activation sequence of discrete brain areas during cognitive processes: results from magnetic field tomography

Magnetic field tomography is a technique for extracting 3-dimensional estimates of current density in the brain, from non-contact, non-invasive measurements of the magnetic field generated by the brain. It allows visualisation of both cortical and subcortical focal activation patterns at millisecond intervals, and the relative time difference between active cortical areas. We have used this technique to study the activation history of discrete brain regions associated with the preparation for, initiation and inhibition of movement, and movement itself in a CNV paradigm. The strongest focal activities are found within well defined cortical regions, namely the auditory (A1), sensorimotor (SM1), medial parietal area (MPA) and anterior supplementary motor area (SMA). For the movement condition, activation history differs for the warning stimulus and the stimulus initiating movement.

Fatal parathyroid hormone-related protein-induced humoral hypercalcemia of malignancy in a 3-month-old infant

Parathyroid hormone-related protein (PTHrP) is the factor responsible for the syndrome of humoral hypercalcemia of malignancy (HHM). The syndrome is well documented in adult cancer patients, but has not previously been described in young children. We report the case of a 3-month-old infant who developed refractory hypercalcemia (peak total calcium 13.8 mg/dl; normal 8.5-10.5, ionized calcium 3.3 meq/l; normal 2.0-2.5) associated with a high-grade, poorly differentiated malignant hepatic sarcoma. Parathyroid hormone (intact) levels were suppressed (7.5 pg/ml; normal 10-65). Fractional excretion of phosphate was markedly elevated (73.5%; normal 8%-20%) as were urinary cAMP levels (12.48 nmol/dl glomerular filtrate; normal 1.83-4.47) suggesting a PTH-like effect. Increased levels of PTHrP were present both in the serum (4.9 pmol/l; normal for adults < 1.5) and ascitic fluid (6.1 pmol/l). Since previous studies have demonstrated a potential role for PTHrP in the regulation of embryonal tissue differentiation and transmembrane calcium flux, our observation of elevated PTHrP levels associated with the development of a poorly differentiated hepatic sarcoma in a young infant may provide insight into the molecular mechanisms underlying HHM. We suggest that serum or plasma PTHrP levels be determined in all children with hypercalcemia of malignancy in whom the hypercalcemia cannot otherwise be explained.