Tollip, a new component of the IL-1RI pathway, links IRAK to the IL-1 receptor

Interleukin-1 (IL-1) is a proinflammatory cytokine that elicits its pleiotropic effects through activation of the transcription factors NF-kappaB and AP-1. Binding of IL-1 to its receptor results in rapid assembly of a membrane-proximal signalling complex that consists of two different receptor chains (IL-1Rs), IL-1RI and IL-1RAcP, the adaptor protein MyD88, the serine/threonine kinase IRAK and a new protein, which we have named Tollip. Here we show that, before IL-1beta treatment, Tollip is present in a complex with IRAK, and that recruitment of Tollip-IRAK complexes to the activated receptor complex occurs through association of Tollip with IL-1RAcP. Co-recruited MyD88 then triggers IRAK autophosphorylation, which in turn leads to rapid dissociation of IRAK from Tollip (and IL-1Rs). As overexpression of Tollip results in impaired NF-kappaB activation, we conclude that Tollip is an important constituent of the IL-1R signalling pathway.

Splenic Atrophy in Experimental Stroke Is Accompanied by Increased Regulatory T Cells and Circulating Macrophages

Induction of stroke not only produces local ischemia and brain damage, but also has profound effects on peripheral immune responses. In the current study, we evaluated effects on spleen and blood cells 4 days after stroke induction. Surprisingly, there was a less inflammatory cytokine profile in the middle cerebral artery occlusion-affected right brain hemisphere at 96 h compared with earlier time points. Moreover, our results demonstrate that stroke leads to splenic atrophy characterized by a reduction in organ size, a drastic loss of splenocyte numbers, and induction of annexin V+ and TUNEL+ cells within the spleen that are in the late stages of apoptosis. The consequence of this process was to reduce T cell proliferation responses and secretion of inflammatory cytokines, resulting in a state of profound immunosuppression. These changes produced a drastic reduction in B cell numbers in spleen and blood, and a novel increase in CD4+FoxP3+ regulatory T cells. Moreover, we detected a striking increase in the percentage of nonapoptotic CD11b+ VLA-4-negative macrophages/monocytes in blood. Immunosuppression in response to brain injury may account for the reduction of inflammatory factors in the stroke-affected brain, but also potentially could curtail protective immune responses in the periphery. These findings provide new evidence to support the contention that damage to the brain caused by cerebral ischemia provides a powerful negative signal to the peripheral immune system that ultimately induces a drastic state of immunosuppression caused by cell death as well as an increased presence of CD4+FoxP3+ regulatory T cells.

Varieties of groups and the perception of group entitativity

Three studies examined perceptions of the entitativity of groups. In Study 1 (U.S.) and Study 2 (Poland), participants rated a sample of 40 groups on 8 properties of groups (e.g., size, duration, group member similarity) and perceived entitativity. Participants also completed a sorting task in which they sorted the groups according to their subjective perceptions of group similarity. Correlational and regression analyses were used to determine the group properties most strongly related to entitativity. Clustering and multidimensional scaling analyses in both studies identified 4 general types of groups (intimacy groups, task groups, social categories, and loose associations). In Study 3, participants rated the properties of groups to which they personally belonged. Study 3 replicated the results of Studies 1 and 2 and demonstrated that participants most strongly valued membership in groups that were perceived as high in entitativity.

Tunable laser resonance raman spectroscopy of bacteriorhodopsin

Bacteriorhodopsin is a rhodopsin-like protein found in the cell membrane of Halobacterium halobium. It shows an absorption maximum at 570 nm and, in the light, undergoes cyclic spectral changes which include a relatively long-lived complex absorbing maximally at 412 nm. Excitation profiles have been obtained with several laser frequencies for two vibrations in the resonance Raman spectrum of bacteriorhodopsin. The results show that the Schiff base retinylidene lysine linkage is protonated in the 570 nm complex and that in the 412 nm complex it is unprotonated. The 412 nm complex must be present at appreciable concentrations when bacteriorhodopsin is exposed to high-energy argon ion laser light of the Raman spectrophotometer at room temperature. We conclude that the observed C=N stretch at 1622 cm(-1) in the room temperature spectra, which in an earlier study by Mendelsohn was interpreted as evidence for an unprotonated linkage in bacteriorhodopsin, results from the presence of the 412 nm complex.

High-resolution nonlinear optical imaging of live cells by second harmonic generation

By adapting a laser scanning microscope with a titanium sapphire femtosecond pulsed laser and transmission optics, we are able to produce live cell images based on the nonlinear optical phenomenon of second harmonic generation (SHG). Second harmonic imaging (SHIM) is an ideal method for probing membranes of living cells because it offers the high resolution of nonlinear optical microscopy with the potential for near-total avoidance of photobleaching and phototoxicity. The technique has been implemented on three cell lines labeled with membrane-staining dyes that have large nonlinear optical coefficients. The images can be obtained within physiologically relevant time scales. Both achiral and chiral dyes were used to compare image formation for the case of single- and double-leaflet staining, and it was found that chirality plays a significant role in the mechanism of contrast generation. It is also shown that SHIM is highly sensitive to membrane potential, with a depolarization of 25 mV resulting in an approximately twofold loss of signal intensity.

Cortical-basal ganglionic degeneration

We report our experience with 15 patients believed to have cortical-basal ganglionic degeneration. The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Characteristic manifestations include cortical sensory loss, focal reflex myoclonus, "alien limb" phenomena, apraxia, rigidity and akinesia, a postural-action tremor, limb dystonia, hyperreflexia, and postural instability. The asymmetry of symptoms and signs is often striking. Brain imaging may demonstrate greater abnormalities contralateral to the more affected side. Postmortem studies in 2 patients revealed the characteristic pathologic features of swollen, poorly staining (achromatic) neurons and degeneration of cerebral cortex and substantia nigra. Biochemical analysis of 1 brain showed a severe, diffuse loss of dopamine in the striatum. This condition is more frequent than previously believed, and the diagnosis can be predicted during life on the basis of clinical findings. However, as with other "degenerative" diseases of the nervous system, a definitive diagnosis of cortical-basal ganglionic degeneration requires confirmation by autopsy.

Direct measurement of pO2 distribution and bioreductive enzymes in human malignant brain tumors

PURPOSE

To measure the oxygen status of human malignant brain tumors in vivo and to determine the activities and expression of bioreductive enzymes in these same human brain tumor samples, as a means of assessing their suitability as targets for bioreductive drug therapy.

METHODS AND MATERIALS

A polarographic oxygen electrode was used to measure the intratumoral oxygen tension in twenty patients with malignant brain tumors during open brain surgery, performed under standard anaesthetic conditions. Six different tracks, each with a path length of 22 mm, were recorded per patient representing 192 readings. Following pO2 measurements the tumors were resected and stored in liquid N2 for subsequent bioreductive enzyme analysis. Eight human malignant brain tumors were assessed, by enzyme activity and western blot expression, for the presence of various bioreductive enzymes. These enzymes included DT-diaphorase, NADH cytochrome b5 reductase, and NADPH cytochrome P-450 reductase. Of these eight gliomas analyzed six samples were incubated with the bioreductive drug tirapazamine, in the presence of cofactor(s), to establish whether human brain tumors could metabolize this compound.

RESULTS

Both the high grade intrinsic and metastatic brain tumors showed significant regions of hypoxia. All the tumors subjected to enzyme profiling contained the bioreductive enzymes, DT-diaphorase, NADH cytochrome b5 reductase and NADPH cytochrome P-450 reductase. Also all six of the brain tumors investigated could metabolize tirapazamine to the two-electron reduction product.

CONCLUSION

These findings would favor primary brain tumors as suitable targets for bioreductive therapy.

Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis

Fifteen centers for orthopaedic treatment of the foot and ankle participated in a prospective randomized trial to compare several nonoperative treatments for proximal plantar fasciitis (heel pain syndrome). Included were 236 patients (160 women and 76 men) who were 16 years of age or older. Most reported duration of symptoms of 6 months or less. Patients with systemic disease, significant musculoskeletal complaints, sciatica, or local nerve entrapment were excluded. We randomized patients prospectively into five different treatment groups. All groups performed Achilles tendon- and plantar fascia-stretching in a similar manner. One group was treated with stretching only. The other four groups stretched and used one of four different shoe inserts, including a silicone heel pad, a felt pad, a rubber heel cup, or a custom-made polypropylene orthotic device. Patients were reevaluated after 8 weeks of treatment. The percentages improved in each group were: (1) silicone insert, 95%; (2) rubber insert, 88%; (3) felt insert, 81%; (4)stretching only, 72%; and (5) custom orthosis, 68%. Combining all the patients who used a prefabricated insert, we found that their improvement rates were higher than those assigned to stretching only (P = 0.022) and those who stretched and used a custom orthosis (P = 0.0074). We conclude that, when used in conjunction with a stretching program, a prefabricated shoe insert is more likely to produce improvement in symptoms as part of the initial treatment of proximal plantar fasciitis than a custom polypropylene orthotic device.

Reductase enzyme expression across the National Cancer Institute Tumor cell line panel: correlation with sensitivity to mitomycin C and EO9

BACKGROUND

Many antitumor drugs require metabolic activation to exert their cytotoxic or cytostatic effects. The so-called bioreductive compounds, whose conversion into active antitumor agents is catalyzed by reductase enzymes, are examples of such drugs. The identification of specific enzymes involved in the activation of these compounds is important in understanding cellular factors that may influence drug antitumor activity.

PURPOSE

We measured expression levels of three different reductase enzymes-DT-diaphorase [NAD(P)H (i.e., reduced nicotinamide adenine dinucleotide, with or without phosphate): quinone oxidoreductase]; NADPH:cytochrome P-450 reductase; and NADH (i.e., reduced nicotinamide adenine dinucleotide): cytochrome-b5 reductase- in 69 cell lines (most of the National Cancer Institute [NCI] human tumor cell panel) to see if relationships could be established between the activities of these enzymes and cellular sensitivities to the bioreductive compounds mitomycin C and EO9.

METHODS

For all 69 cell lines, the activity of each enzyme was determined using cellular extracts and photometric assays involving the reduction of cytochrome c. Western blot analysis was used to measure the relative amount of DT-diaphorase protein in each extract, and coupled reverse transcription and polymerase chain reactions were employed to assess DT-diaphorase and NADPH:cytochrome P-450 reductase messenger RNA (mRNA) levels in a subset of the cell lines. The cytotoxic and/or cytostatic activities of mitomycin C and EO9 toward the cell lines were determined under aerobic conditions. Relationships between enzyme activity levels and drug sensitivities were assessed by use of the COMPARE program and Pearson correlation coefficients.

RESULTS

In general, DT-diaphorase activity levels were higher than those observed for the other two reductases across the entire cell line panel. Measured activities for all three enzymes varied among cell lines derived from the same tissue as well as between lines derived from different tissues; however, tissue-specific patterns of expression could be discerned. Differences in the activity levels of individual enzymes appeared to reflect differences in corresponding enzyme protein and/or mRNA levels. A relationship between enzyme activity and chemosensitivities to mitomycin C and EO9 was observed only for DT-diaphorase (Pearson correlation coefficient = .424 [two-sided P<.0005] for mitomycin C and .446 [two-sided P< or = to .0013] for EO9).

CONCLUSIONS

Reductase enzyme expression is heterogeneous across human tumor cell lines, and tissue-specific patterns of expression are apparent. DT-diaphorase activity levels correlate with sensitivities to mitomycin C and EO9, supporting a role for this enzyme in the bioactivation of these anticancer compounds.

IMPLICATIONS

Comparison of biochemical, molecular biological, and chemosensitivity data obtained from screening a large number of cell lines (e.g., the NCI tumor cell line panel) may facilitate investigation of factors influencing drug antitumor activity. The knowledge gained may be of value in the development of new anticancer agents or in the selection of patients to receive specific therapies.

Deep venous thrombosis: detection by using indirect CT venography. The Pulmonary Angiography-Indirect CT Venography Cooperative Group

PURPOSE

To assess the clinical benefits of performing indirect computed tomographic (CT) venography after pulmonary CT angiography to detect deep venous thrombosis (DVT) in patients suspected of having a pulmonary embolism.

MATERIALS AND METHODS

The authors prospectively enrolled 541 consecutive patients who underwent pulmonary CT angiography for suspected pulmonary embolism at seven institutions. Using a protocol that optimizes venous enhancement without additional contrast material injection, the authors obtained contiguous images from the pelvis to the popliteal fossa. Ultrasonography (US) also was performed in 116 patients.

RESULTS

DVT was found at indirect CT venography in 45 (8%), and pulmonary embolism was found at pulmonary CT angiography in 91 (17%) of 541 patients. Among the 45 patients with DVT, DVT occurred in 16 patients who had no pulmonary embolism at pulmonary CT angiography, which increased the diagnosis of thromboembolic disease by 18%. Among 116 patients who underwent US and indirect CT venography, 15 had DVT at US, and in all 15, DVT also was seen at indirect CT venography. In four additional cases, DVT was seen at only indirect CT venography.

CONCLUSION

Among patients suspected to have pulmonary embolism, a substantial number had DVT in the absence of pulmonary embolism. Combined pulmonary CT angiography-indirect CT venography can depict these cases with accuracy comparable to that of US and thus could have a significant effect on patient care.

Glutathione and glutathione-dependent enzymes in ovarian adenocarcinoma cell lines derived from a patient before and after the onset of drug resistance: intrinsic differences and cell cycle effects

The regulation of glutathione and various glutathione-dependent enzymes has been studied in two ovarian adenocarcinoma cell lines derived from a patient before (PE01) and after (PE04) the onset of drug resistance to cis-platinum, chlorambucil and 5-fluorouracil. Reduced glutathione levels were higher in the drug resistant cells (PE04). This could possibly be attributed to a much higher (6.5-fold) gamma-glutamyl-transpeptidase activity. In addition, glutathione-S-transferase (GST) and glutathione peroxidase were 2.9- and 2.3-fold higher in this cell line. Analysis of the GST subunit composition showed both cell lines contained high levels of the acidic GST and lower concentrations of a basic isozyme. The difference in GST activity between PE01 and PE04 did not appear to be related to the levels of these GST subunits. GSH, glutathione peroxidase and gamma-glutamylcysteinyl synthetase were all found to be regulated during the cell cycle, higher levels being detected in logarithmic versus confluent cultures of PE01 and PE04 and MCF7. This did affect some of the differences between PE01 and PE04 and therefore may be a contributing factor to the differential sensitivity of these cells to cytotoxic compounds. The above data provide the first evidence that tumour cells obtained from a patient before and after the onset of drug resistance have significant differences in glutathione-dependent enzyme content.

Keratin expression in human mammary epithelial cells cultured from normal and malignant tissue: relation to in vivo phenotypes and influence of medium

The luminal and basal epithelial cells in the human mammary gland can be distinguished in tissue sections on the basis of the pattern of keratins they express. Moreover, the invasive cells in primary carcinomas show a keratin profile that corresponds to that of the dominant luminal cell (7, 8, 18, 19). When homogeneous populations of luminal epithelial cells from milk or from breast cancer metastases are cultured the profile of keratin expression seen in vivo is maintained. We have therefore used monospecific antibodies reactive with individual keratins to examine the phenotype of cells cultured in three different media from reduction mammoplasty tissue that contains both luminal and basal cells. The phenotype of cells cultured from primary breast cancers in one of these media (MCDB170) has also been examined. In characterizing cell phenotypes, antibodies to a polymorphic epithelial mucin (PEM) expressed in vivo by luminal cells, and to smooth muscle (a) actin, expressed in vivo by basal cells, have also been used. Our results show that proliferation of different cell phenotypes is selected for in different media. In milk mix (MX) developed for growth of luminal cells from milk, only the luminal cell phenotype proliferates (for only 1 or 2 passages). In medium MCDB 170, which was developed for long-term growth of human mammary epithelial cells from reduction mammoplasty organoids, cells from the basal layer proliferate, while in MM medium the basal phenotype dominates, but a few cells with the luminal phenotype are found. Around passage 3, in medium MCDB 170, most cells senesce and a subpopulation of cells proliferates on further passage. These cells retain expression of the basal epithelial keratins but also express some features characteristic of luminal epithelial cells, suggesting that the basal layer may contain a stem cell that can develop along the luminal lineage. In culture, however, they do not express keratin 19, which in vivo is a feature of the fully differentiated luminal cell. The cells cultured from primary breast cancer in medium MCDB 170 have a similar keratin profile to that of the normal cells cultured in this medium. They do not express keratin 19, even though the invasive cells in primary cancers homogeneously express this keratin in vivo. The invasive phenotype, which in its keratin profile corresponds to the differentiated luminal cell and that of the metastatic cancer lines, cannot be cultured from primary breast cancers using MX, which supports proliferation of the corresponding normal cell.

Borna disease virus, a negative-strand RNA virus, transcribes in the nucleus of infected cells

Borna disease virus, an unclassified infectious agent, causes immune-mediated neurologic disease in a wide variety of animal hosts and may be involved in pathogenesis of selected neuropsychiatric diseases in man. Initial reports suggested that Borna disease virus is a single-stranded RNA virus. We describe here a method for isolation of viral particles that has allowed definitive identification of the genome as containing a negative-polarity RNA. Further, we show that the viral mRNAs are transcribed in the nucleus.

Disulfide bond dihedral angles from Raman spectroscopy

Raman spectra of several compounds containing the CS-SC moiety were obtained (in the solid phase) from 450-800 cm(-1) to investigate the S-S and C-S stretching behavior. The S-S stretching frequency varied linearly with the CS-SC dihedral angle (obtained from either x-ray or neutron diffraction or ultraviolet absorption) for compounds whose CC-SS dihedral angles were not very different. The ratio of the intensities of the S-S and C-S stretching bands exhibited no recognizable correlation with either the CS-SC dihedral angle or the CSS bond angle, probably because this ratio is sensitive to the crystalline environment. The linear dependence of the S-S stretching frequency on dihedral angle leads to a dihedral angle for the plant hormone, malformin A, that is in excellent agreement with that estimated from the longest wavelength CS-SC ultraviolet absorption band.

Near Field Scanning Optical Microscopy (NSOM): Development and Biophysical Applications

A new method for high-resolution imaging, near-field scanning optical microscopy (NSOM), has been developed. The concepts governing this method are discussed, and the technical challenges encountered in constructing a working NSOM instrument are described. Two distinct methods are presented for the fabrication of well-characterized, highly reproducible, subwavelength apertures. A sample one-dimensional scan is provided and compared to the scanning electron micrograph of a test pattern. From this comparison, a resolution of > 1,500 A (i.e., approximately lambda/3.6) is determined, which represents a significant step towards our eventual goal of 500 A resolution. Fluorescence has been observed through apertures smaller than 600 A and signal-to-noise calculations show that fluorescent imaging should be feasible. The application of such imaging is then discussed in reference to specific biological problems. The NSOM method employs nonionizing visible radiation and can be used in air or aqueous environments for nondestructive visualization of functioning biological systems with a resolution comparable to that of scanning electron microscopy.

A light source smaller than the optical wavelength

A method has been developed for the efficient emission of light from subwavelength dimensions. It is based on packaging photons as molecular excitons, effectively reducing the volume of the light beam by 10(9) and making possible propagation through dimensions of 1 nanometer. Molecular microcrystals are grown in the tips of micropipettes that have inner diameters of 100 nanometers or less. Measurements are presented that demonstrate this improvement in transmission for pipettes of various diameters. The ultrasmall dimensions of these light sources, the wavelength range (ultraviolet to red) of their emission, their ease of production, and their expected unique abilities for high efficiency excitation-imaging of surfaces portend significant applications for this methodology.

How imprinting centres work

Imprinted genes tend to be clustered in the genome. Most of these clusters have been found to be under the control of discrete DNA elements called imprinting centres (ICs) which are normally differentially methylated in the germline. ICs can regulate imprinted expression and epigenetic marks at many genes in the region, even those which lie several megabases away. Some of the molecular and cellular mechanisms by which ICs control other genes and regulatory regions in the cluster are becoming clear. One involves the insulation of genes on one side of the IC from enhancers on the other, mediated by the insulator protein CTCF and higher-order chromatin interactions. Another mechanism may involve non-coding RNAs that originate from the IC, targeting histone modifications to the surrounding genes. Given that several imprinting clusters contain CTCF dependent insulators and/or non-coding RNAs, it is likely that one or both of these two mechanisms regulate imprinting at many loci. Both mechanisms involve a variety of epigenetic marks including DNA methylation and histone modifications but the hierarchy of and interactions between these modifications are not yet understood. The challenge now is to establish a chain of developmental events beginning with differential methylation of an IC in the germline and ending with imprinting of many genes, often in a lineage dependent manner.

Efficacy of beta-lapachone in pancreatic cancer treatment: exploiting the novel, therapeutic target NQO1

NAD(P)H:quinone oxidoreductase (NQO1) is elevated in human pancreatic cancers. We hypothesized that beta-lapachone, a novel 1,2-naphthoquinone with potential antitumor activity in cancer cells expressing elevated levels of NQO1, would induce cytotoxicity in pancreatic cancer cells, wherein this two-electron reductase was recently found elevated. beta-lapachone decreased clonogenic cell survival, metabolic cell viability, and anchorage- independent growth in soft agar. The cytotoxic in vitro effects of beta-lapachone were inhibited with coadministration of dicumarol, a specific inhibitor of NQO1. In preestablished human pancreatic tumor xenografts in nude mice, beta-lapachone demonstrated greater tumor growth inhibition when given intratumorally compared to when complexed with cyclodextrin to increase its bioavailability. Due to the poor prognosis of patients with pancreatic cancer and the limited effectiveness of surgery, chemotherapy, and radiation therapy, treatment regimens based on sound, tumor-specific rationales are desperately need for this disease.

The painful metal-on-metal hip resurfacing

We carried out metal artefact-reduction MRI, three-dimensional CT measurement of the position of the component and inductively-coupled plasma mass spectrometry analysis of cobalt and chromium levels in whole blood on 26 patients with unexplained pain following metal-on-metal resurfacing arthroplasty. MRI showed periprosthetic lesions around 16 hips, with 14 collections of fluid and two soft-tissue masses. The lesions were seen in both men and women and in symptomatic and asymptomatic hips. Using three-dimensional CT, the median inclination of the acetabular component was found to be 55 degrees and its positioning was outside the Lewinnek safe zone in 13 of 16 cases. Using inductively-coupled plasma mass spectrometry, the levels of blood metal ions tended to be higher in painful compared with well-functioning metal-on-metal hips. These three clinically useful investigations can help to determine the cause of failure of the implant, predict the need for future revision and aid the choice of revision prostheses.

Second-harmonic imaging microscopy of living cells

Second harmonic generation (SHG) has been developed in our laboratories as a high-resolution nonlinear optical imaging microscopy for cellular membranes and intact tissues. SHG shares many of the advantageous features for microscopy of another more established nonlinear optical technique: two-photon excited fluorescence (TPEF). Both are capable of optical sectioning to produce three-dimensional images of thick specimens and both result in less photodamage to living tissue than confocal microscopy. SHG is complementary to TPEF in that it uses a different contrast mechanism and is most easily detected in the transmitted light optical path. It can be used to image membrane probes with high membrane specificity and displays extraordinary sensitivity in reporting membrane potential; it also has the ability to image highly ordered structural proteins without any exogenous labels.

Acetabular fractures in patients aged > 55 years: a systematic review of the literature

The increasing prevalence of osteoporosis in an ageing population has contributed to older patients becoming the fastest-growing group presenting with acetabular fractures. We performed a systematic review of the literature involving a number of databases to identify studies that included the treatment outcome of acetabular fractures in patients aged > 55 years. An initial search identified 61 studies; after exclusion by two independent reviewers, 15 studies were considered to meet the inclusion criteria. All were case series. The mean Coleman score for methodological quality assessment was 37 (25 to 49). There were 415 fractures in 414 patients. Pooled analysis revealed a mean age of 71.8 years (55 to 96) and a mean follow-up of 47.3 months (1 to 210). In seven studies the results of open reduction and internal fixation (ORIF) were presented: this was combined with simultaneous hip replacement (THR) in four, and one study had a mixture of these strategies. The results of percutaneous fixation were presented in two studies, and a single study revealed the results of non-operative treatment. With fixation of the fracture, the overall mean rate of conversion to THR was 23.1% (0% to 45.5%). The mean rate of non-fatal complications was 39.8% (0% to 64%), and the mean mortality rate was 19.1% (5% to 50%) at a mean of 64 months (95% confidence interval 59.4 to 68.6; range 12 to 143). Further data dealing with the classification of the fracture, the surgical approach used, operative time, blood loss, functional and radiological outcomes were also analysed. This study highlights that, of the many forms of treatment available for this group of patients, there is a trend to higher complication rates and the need for further surgery compared with the results of the treatment of acetabular fractures in younger patients.

Passive immune globulin therapy in the SIV/macaque model: early intervention can alter disease profile

One of the major questions in AIDS is the role that the host immune system and the virus play in the dynamics of infection and the development of AIDS in an infected individual. In order to test the role of antibody in controlling viral infection, high-dose SIV-immune globulin was passively transferred to infected macaques early in infection. Immune globulin purified from the plasma of an SIV-infected long-term non-progressor macaque (SIVIG) or a pool of normal immune globulin (normal Ig) was infused into SIVsmE660-infected macaques (170 mg/kg) at one and fourteen days post infection. Animals were monitored for SIV-specific antibodies, viremia, plasma antigenemia, and clinical course. All animals were infected by SIV. At 16 months post infection, five macaques in the combined control groups have been euthanized, one as a rapid progressor with debilitating disease at 20 weeks post infection. Four macaques from the comparison groups have signs of AIDS, accompanied by high and increasing levels of virus and p27 antigenemia. One of the ten control animals had a very low virus load in plasma and peripheral blood and lymph node mononuclear cells at all times tested and has remained disease-free. In the SIVIG treatment group, two macaques were euthanized at 18-20 weeks due to AIDS, rapid progressors to disease. Three macaques in the SIVIG group had an initial high level of virus in plasma, peripheral blood mononuclear cells (PBMC), and lymph node mononuclear cells (LNMC), which dropped to baseline at 6 weeks post infection and has remained very low or negative for 16 months, a disease profile which has not been observed in untreated animals in this model to date. These macaques have remained clinically healthy. The sixth treated animal is also healthy, with very low virus burden that is detectable only by nested set polymerase chain reaction (PCR). All SIVIG-treated macaques had no detectable p27 plasma antigenemia for the first 10 weeks of infection, demonstrating that the IgG effectively complexed with the virus. The immunological correlates in the treated animals include development of de novo virus-specific antibodies and/or cytotoxic T cell (CTL), both of which are hallmarks of long term non-progressors. The two SIVIG-treated macaques that progress to disease rapidly had no detectable de novo humoral immune responses, as is often seen in rapid HIV disease in humans. Envelope-specific and virus neutralizing antibodies alone were not sufficient to prevent disease progression, as the plasma of both non-progressors as well as progressors had high titers of envelope-specific and neutralizing antibodies against SIVsmE660. Poor clinical prognosis was associated with moderate to high and increasing virus loads in plasma, PBMC, and lymph nodes. Good clinical prognosis correlated with low or undetectable post acute viremia in the peripheral blood and lymph nodes. We hypothesize that SIVIG reduced the spread of virus by eliminating or reducing plasma virus through immune complexes during the first four to 8 weeks of infection and then maintaining this low level of viremia until the host immune response was capable of virus control. Reduction of virus burden early in infection by passive IgG can alter disease outcome in SIV infection of macaques. Modifications of this strategy may lead to effective early treatment of HIV-1 infection in humans.

Estradiol and G1 reduce infarct size and improve immunosuppression after experimental stroke

Reduced risk and severity of stroke in adult females is thought to depend on normal endogenous levels of estrogen, a well-known neuroprotectant and immunomodulator. In male mice, experimental stroke induces immunosuppression of the peripheral immune system, characterized by a reduction in spleen size and cell numbers and decreased cytokine and chemokine expression. However, stroke-induced immunosuppression has not been evaluated in female mice. To test the hypothesis that estradiol (E2) deficiency exacerbates immunosuppression after focal stroke in females, we evaluated the effect of middle cerebral artery occlusion on infarct size and peripheral and CNS immune responses in ovariectomized mice with or without sustained, controlled levels of 17-beta-E2 administered by s.c. implant or the putative membrane estrogen receptor agonist, G1. Both E2- and G1-replacement decreased infarct volume and partially restored splenocyte numbers. Moreover, E2-replacement increased splenocyte proliferation in response to stimulation with anti-CD3/CD28 Abs and normalized aberrant mRNA expression for cytokines, chemokines, and chemokine receptors and percentage of CD4(+)CD25(+)FoxP3(+) T regulatory cells observed in E2-deficient animals. These beneficial changes in peripheral immunity after E2 replacement were accompanied by a profound reduction in expression of the chemokine, MIP-2, and a 40-fold increased expression of CCR7 in the lesioned brain hemisphere. These results demonstrate for the first time that E2 replacement in ovariectomized female mice improves stroke-induced peripheral immunosuppression.

Generation of neutralizing activity against human immunodeficiency virus type 1 in serum by antibody gene transfer

Although several human immunodeficiency virus (HIV) vaccine approaches have elicited meaningful antigen-specific T-cell responses in animal models, no single vaccine candidate has engendered antibodies that broadly neutralize primary isolates of HIV type 1 (HIV-1). Thus, there remains a significant gap in the design of HIV vaccines. To address this issue, we exploited the existence of rare human monoclonal antibodies that have been isolated from HIV-infected individuals. Such antibodies neutralize a wide array of HIV-1 field isolates and have been shown to be effective in vivo. However, practical considerations preclude the use of antibody preparations as a prophylactic passive immunization strategy in large populations. Our concept calls for an antibody gene of choice to be transferred to muscle where the antibody molecule is synthesized and distributed to the circulatory system. In these experiments, we used a recombinant adeno-associated virus (rAAV) vector to deliver the gene for the human antibody IgG1b12 to mouse muscle. Significant levels of HIV-neutralizing activity were found in the sera of mice for over 6 months after a single intramuscular administration of the rAAV vector. This approach allows for predetermination of antibody affinity and specificity prior to "immunization" and avoids the need for an active humoral immune response against the HIV envelope protein.

Cellular heterogeneity and drug resistance in two ovarian adenocarcinoma cell lines derived from a single patient

Two ovarian cell lines were derived from the ascites of a patient before and after the onset of resistance to chemotherapy involving cis-platinum, chlorambucil and 5-fluorouracil. Characterization of these lines shows them to have various features in common and some significant differences. Cytologically the lines cannot be distinguished and they both contain high concentrations of oestrogen receptor. However, they do differ with respect to their growth characteristics, karyotype, glutathione content and sensitivity to cis-platinum. The karyotypes of the 2 lines show several marker chromosomes in common but the resistant line contained a chromosome 8 and a 17 which were absent from the earlier sensitive line. This suggests a clonal origin with subsequent divergence to a heterogeneous population.