IL-12-deficient mice are defective in IFN gamma production and type 1 cytokine responses

IL-12 is a cytokine that can exert regulatory effects on T and NK cells and promote Th1 responses. To delineate further the physiologic role of IL-12 in immunity, mice deficient for this cytokine were generated. IL-12-deficient mice were impaired but not completely lacking in the ability to produce IFN gamma following endotoxin administration and to mount a Th1 response in vivo, as measured by antigen-induced IFN gamma secretion by immune lymph node cells in vitro. In contrast, secretion of IL-4 was enhanced, while proliferation and secretion of IL-2 and IL-10 were normal following antigen stimulation. DTH responses were significantly reduced in IL-12-deficient mice, but no defect in allogeneic CTL responses was observed. These results indicate that IL-12 plays an essential role in regulating IFN gamma production and in facilitating normal DTH responses. However, other phenomena associated with Th1 responses and cell-mediated immunity, i.e., IL-2 secretion and CTL generation, were not compromised in the absence of IL-12.

Enteropathogenic Escherichia coli: identification of a gene cluster coding for bundle-forming pilus morphogenesis

Sequence flanking the bfpA locus on the enteroadherent factor plasmid of the enteropathogenic Escherichia coli (EPEC) strain B171-8 (O111:NM) was obtained to identify genes that might be required for bundle-forming pilus (BFP) biosynthesis. Deletion experiments led to the identification of a contiguous cluster of at least 12 open reading frames, including bfpA, that could direct the synthesis of a morphologically normal BFP filament. Within the bfp gene cluster, we identified open reading frames that share homology with other type IV pilus accessory genes and with genes required for transformation competence and protein secretion. Immediately upstream of the bfp gene cluster, we identified a potential replication origin including genes that are predicted to encode proteins homologous with replicase and resolvase. Restriction fragment length polymorphism analysis of DNA from six additional EPEC serotypes showed that the organization of the bfp gene cluster and its juxtaposition with a potential plasmid origin of replication are highly conserved features of the EPEC biotype.

Cloning, direct expression, and purification of a snake venom cardiotoxin in Escherichia coli

The cardiotoxin analogue III (CTX III), isolated from the Taiwan cobra (Naja naja atra) venom, is a sixty-amino acid, all beta-sheet protein. We report the direct expression of CTX III from its synthetic gene as inclusion bodies in Escherichia coli. The yield of the expressed protein is about 40 mg/liter of the culture. CTX III trapped as inclusion bodies is dissolved and refolded by the slow refolding technique. The refolded protein is purified by reverse phase high performance liquid chromatography. The purified and refolded CTX III sample is further characterized by SDS-PAGE, circular dichroism, two-dimensional NMR spectroscopy and haemolytic activity. To our knowledge, this is the first report of the direct expression and purification of snake venom cardiotoxins.

Biological function and distribution of human interleukin-12 receptor beta chain

We previously described the cloning of a cDNA encoding an interleukin-12 receptor (IL-12R) subunit, designated beta, that bound IL-12 with low affinity when expressed in COS cells. We now report that a pair of monoclonal antibodies (mAb), 2B10 and 2.4E6, directed against different epitopes on the IL-12R beta chain, when used in combination, strongly inhibited IL-12-induced proliferation of activated T cells, IL-12-induced secretion of interferon-gamma by resting peripheral blood mononuclear cells (PBMC), and IL-12-mediated lymphokine-activated killer cell activation. The mAb had no effect on lymphoblast proliferation induced by IL-2, -4, or -7. Thus, the IL-12R beta chain appears to be an essential component of the functional IL-12R on both T and natural killer (NK) cells. We previously observed that high affinity IL-12R were expressed on activated T and NK cells, but not B cells. Studies using flow cytometry and reverse transcription-polymerase chain reaction analysis showed that IL-12R beta chain was expressed on several human T, NK, and (surprisingly) B cell lines, but not on non-lymphohematopoietic cell lines. The Kit225/K6 (T cell) and SKW6.4 (B cell) lines were found to express the greatest amounts of IL-12R beta chain (800-2500 sites/cell); however, Kit225/K6 but not SKW6.4 cells bound IL-12. Similar to SKW6.4 B cells, activated tonsillar B lymphocytes expressed IL-12R beta chain but, consistent with previous results, did not display detectable IL-12 binding. Likewise, up to 72% of resting PBMC from normal volunteer donors expressed IL-12R beta, but did not bind measurable amounts of IL-12. These results indicate that expression of IL-12R beta is essential, but not sufficient, for expression of functional IL-12R. We speculate that expression of functional, high-affinity IL-12R may require the presence of a second subunit that is more restricted in its expression than IL-12R beta.

Analog electronic cochlea design using multiplexing switched-capacitor circuits

A new design methodology is proposed to realize a real cochlea using the multiplexing switched-capacitor circuits. The proposed technique is based upon the transmission-line model proposed by Zwislocki (1950). At the cost of the increase in the number of clock phases, the decay rate in the transition region of the filter section can be increased by adding only a few components. Therefore, the components and chip area of the designed silicon cochlea can be small. An experimental chip containing four filter sections has been designed and fabricated. The measured frequency responses from the 32-section cochlea formed by cascading nine fabricated chips are consistent with both theoretical calculation results and observed behavior of a real cochlea. Moreover, the designed silicon cochlea has the dynamic range of 67 dB in each section and a low sensitivity to process variations. Thus it is suitable for VLSI implementation with the associated neural network.

Differentiation of absorption and first-pass gut and hepatic metabolism in humans: studies with cyclosporine

The low and variable bioavailability of cyclosporine has been attributed to poor absorption. However, recent studies have suggested that intestinal first-pass metabolism exerts a significant effect on bioavailability. We describe theory and methods to differentiate the contribution from oral absorption and intestinal and hepatic metabolism to overall cyclosporine bioavailability. Analysis of data from previous studies in our laboratories shows that in the absence of intestinal metabolism, cyclosporine absorption from its presently available dosage form averages at least 65% +/- 12% in healthy volunteers and 77% +/- 19% in kidney transplant patients. Analysis also suggests that the extraction ratio for cyclosporine in the gut is approximately twice the hepatic extraction and that cyclosporine absorption does not present a problem, with an average of 86% of the drug absorbed intact from its commercially available product in healthy volunteers. The boundary condition analysis described should have broad application in the differentiation of factors responsible for poor bioavailability.

Purification of chlorpromazine-sensitive GTPase from rat cerebral cortex

The chlorpromazine-sensitive GTPase from the cell membrane of rat cerebral cortex was purified to homogenity by using DEAE Bio-Gel A agarose, hydroxyapatite and heparin agarose chromatography. The purified chlorpromazine-sensitive GTPase was purified 370-fold to obtain a final specific activity of 40 mumol GTP hydrolyzed2min/mg protein. The purified enzyme was inhibited by chlorpromazine but not by compound 48/80. Magnesium was required for its activity instead of calcium. The purified enzyme had an apparent pH optimum of 8.0, and molecular weight was estimated to be 58,000.

Assessment of postdischarge concerns of coronary artery bypass graft patients

Cardiac surgery patients are currently being discharged from hospitals earlier than ever before. Problems experienced by these patients after discharge are less well documented in the literature than are predischarge problems. Understanding the nature of patients' concerns about their recovery at home can help clinicians plan interventions to alleviate those concerns. This study documents the nature of patients' concerns after discharge home. Data were collected over a 3-year period using a 24-hour telephone contact system. Of 356 coronary artery bypass graft surgery patients discharged, 196 made 392 telephone calls regarding 445 concerns. These concerns were recorded systematically and analyzed for patterns of commonality. Patients' primary concerns were related to leg incision healing, pain, leg swelling, and medications. Recommendations for discharge planning are discussed.

Multiple sclerosis in children: report of two cases

Multiple sclerosis is a disease of white matter in the central nervous system characterized by clinically relapsing and remitting course. It is rare in children and the mean age of onset is about 30 years. To establish diagnosis, one must note that white matter lesions are disseminated in time and place. We report two female patients with recurrent episodes of headaches, seizures, hemiparesis, and optic neuritis since childhood. Four of the five CT scans done during the relapse attacks in these two patients showed negative findings. The only one abnormal finding was decreased density in the white matter over the right frontoparietal area. MRI showed multiple focal patches of high signal intensity in white matter on T2-weighted image in Case 1, and increased signal intensity on the right paraventricular region on T2-weighted image in Case 2. Now, MRI is the neuroimaging test of choice, and makes early diagnosis possible. It is useful in assessing the extent of multiple sclerosis and in monitoring the clinical course.

A comparison of bone densitometry measurements of the central skeleton in post-menopausal women with and without vertebral fracture

The purpose of this investigation was to compare the ability of two different bone densitometry techniques (quantitative computed tomography and dual X-ray absorptiometry) to discriminate subjects without any vertebral fracture from those with definite vertebral fractures. Bone mineral density (BMD) was determined in 112 post-menopausal women. 83 women were classified free of vertebral fracture and 29 were considered to have definite vertebral fractures. Quantitative computed tomography (QCT) was performed using three different spinal regions of interest. Dual X-ray absorptiometry (DXA) was measured at the spine (both in posteroanterior (PA) and lateral (L-DXA) projection, and at hip (total, neck and Ward regions). An additional estimated volumetric BMD was derived from the PA and L-DXA spine scans. Individuals with definite vertebral fractures had lower bone mineral density for each of the methods and regions of interest (ROI). Spinal QCT results, total and Ward hip DXA results showed the greatest percentage decrement. Odds ratio estimates revealed a significant relationship between BMD and fracture with spinal QCT, hip, and volumetric spinal DXA. The greatest areas under the receiver operating characteristic (ROC) curves were found with results of spinal QCT, total and Ward hip DXA, and volumetric spinal DXA measurements. It is concluded that spinal QCT and femoral total DXA measurement may be preferred to PA and lateral L3 DXA measurements.

Dissemination and tissue invasiveness in murine acute leukemia associated with acquisition of p53 mutation and loss of wild-type p53

Approximately 60% of mice treated with split-dose radiation develop leukemias that disseminate widely through the body, whereas 40% of the treated mice incur leukemias that are contained entirely within the thymus. We studied the status of p53 in non-cultured samples of thymic leukemias and in cell lines established from these leukemias. In those mice with disseminated disease, primary samples were also obtained from visceral leukemic organs, and cell lines were established from these leukemic organs for further study. Using single-strand conformation polymorphism (SSCP), nucleic acid sequencing, and immunochemical analysis, we found that mutation of both p53 alleles occurred in leukemic cell lines developed from nine of 10 disseminated leukemias; mutation of one p53 allele with the other remaining wild-type occurred in one disseminated leukemia. A p53 mutation unique for each mouse was found in all cell lines established from the different leukemic organs of each mouse. The same mutation was also found in the non-cultured leukemic tissues of each mouse, indicating that the mutations originated in vivo and were clonal. Seven of seven non-disseminating thymomas possessed wild-type p53 only. Hence, in vivo dissemination and tissue invasiveness were associated with the loss of wild-type p53 by mutation of both alleles or by mutation and loss of heterozygosity, as revealed by studies of cell lines established from them. The selective in vivo dissemination of leukemia cells possessing p53 mutations had a parallel in vitro. Leukemia cell lines from mice harboring disseminating leukemia were established more readily (success rate greater than 80%) than lines from mice harboring thymic nondisseminating leukemia (success rate less than 10%). Additionally, while mice with disseminating leukemia harbored a mixture of wild-type and mutant p53-encoding thymoma cells, only cell lines possessing mutant p53 became established in culture. Mutations found in thymoma cell lines were always detectable by SSCP and sequencing of DNA extracted from non-cultured thymoma tissue. However, in non-cultured leukemic tissue of visceral organs, the clonal p53 mutations found in cell lines established from them were often not detectable by SSCP or sequencing but were detectable by immunochemical analysis or polymerase chain reaction amplification. This indicates an unexpected degree of masking of mutant genes by wild-type genes present in the leukemic tissue. Masking was evident even in leukemic organs that were grossly larger than normal organs. Hence, routine screening of leukemic tissue by SSCP and sequencing may result in a highly significant underestimation of the incidence of p53 mutations.(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of dural involvement by magnetic resonance imaging in adult patients with acute leukemias--preliminary experience

Retrospectively, the dura in 18 adult patients with acute leukemia were evaluated by gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI). Abnormal dural enhancements were detected in three of four patients with positive cerebrospinal fluid (CSF) cytology, in one of five with suspicious central nervous system (CNS) disease, and in two of nine asymptomatic patients. Computed tomography failed to demonstrate any dural abnormality in these six patients. The abnormal dural enhancement was found in either (a) the brain and the spine, (b) the thoracolumbar spine, or (c) the area adjacent to the parenchymal lesions. Three of the patients were in hematological remission stage; disappearance of the abnormal dural enhancement was observed 1-2 months after radiotherapy and high-dose systemic chemotherapy. The results suggest that MRI is a sensitive and noninvasive imaging modality and superior to CT in detecting dural disease in leukemic patients.

Angiographic findings in Tolosa-Hunt syndrome: a case report

A 71-year-old man suffered from left-side throbbing headache over the region of the fifth cranial nerve first division, followed by left ptosis and ophthalmoplegia. Under tentative diagnosis of Tolosa-Hunt syndrome (THS), oral prednisolone 60 mg was given daily. His headache and ophthalmoplegia dramatically improved within 24 hours. Magnetic resonance (MR) imaging and computed tomography (CT) of the head were negative. However, irregularity in the siphon of the left internal carotid artery was disclosed by angiography. This case illustrates that angiography may be useful in diagnosing THS, when CT and MR imaging are negative.

Determination of anticancer drug vitamin K3 in plasma by high-performance liquid chromatography

Synthetic vitamin K3 (VK3, 2-methyl-1,4-naphthoquinone, or menadione) has been found to exhibit antitumor activity against various human cancer cells at relative high dose. Parallel to our study on the mechanism of VK3 action and for future clinical trials in Taiwan, we developed a simple, sensitive and accurate high-performance liquid chromatographic method for the determination of VK3 in biological fluids. VK3 was extracted from the plasma samples with n-hexane. The chromatographic separation employed an ODS analytical column (5 microns, 250 x 4.6 mm I.D.) with a mobile phase of methanol-water (70:30, v/v) and UV detection at 265 nm. On completely drying of the extraction solution, n-hexane, by a stream of nitrogen, menadione was lost to a great extent. Methanol (70%, 200 microliters) was added to the extraction solvent after extraction and centrifugation to prevent the loss of menadione. The absolute recovery was 82.4 +/- 7.69% (n = 7). The within-day and between-day calibration curves of VK3 in plasma in the ranges of interest (0.01-10.00 micrograms/ml; 0.01-5.00 micrograms/ml) showed good linearity (r > 0.999) and acceptable precision. The limit of quantitation of VK3 was 10 ng/ml in plasma. This method has been successfully applied to a pilot pharmacokinetic study of VK3 in rabbits receiving an intravenous high-dose bolus injection of 75 mg menadiol sodium diphosphate (Synkayvite). The pharmacokinetic properties of menadione could be described adequately by an open two-compartment model. The mean half-life of menadiol (transformation to menadione) was 2.60 +/- 0.12 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Activated T cells induce interleukin-12 production by monocytes via CD40-CD40 ligand interaction

Previous studies on the production of interleukin-12 (IL-12) have shown that it is released, together with other proinflammatory cytokines, shortly after exposure of phagocytic cells to a variety of pathogens. We here report that IL-12 is also released during the recall response to soluble antigen (Ag) devoid of intrinsic adjuvant activity. We show that activated T cells induce the production of IL-12 by monocytes via a mechanism involving the interaction of T cell-associated CD40 ligand with CD40 on monocytes. The data suggest that Ag presentation on monocytes favors the persistence of type 1 responses.

Spinal bone mineral assessment in postmenopausal women: a comparison between dual X-ray absorptiometry and quantitative computed tomography

We compared quantitative computed tomography (QCT) and dual X-ray absorptiometry (DXA) with respect to their ability to discriminate subjects with and without prevalent vertebral fractures. In 240 post-menopausal women (mean age 63.7 +/- 6.9 years) lateral spine radiographs (T4-L4) were reviewed for the presence of vertebral fracture. Using a semiquantitative technique to grade the severity of vertebral deformities, we classified fractures as mild, moderate or severe (grade 1 to 3, respectively). Postero-anterior DXA (PA-DXA) and lateral DXA (L-DXA) measurements (L2-4) as well as QCT measurements of the lumbar spine (T12-L3 or L1-14) were obtained in all women. Seventy-two women were diagnosed with at least one fracture, and of these 40 were graded as mild. Comparing normal women with fractured women, we found the area under the receiver operating characteristics (ROC) curves to be greatest for QCT (0.81), followed by L-DXA (0.72) and PA-DXA (0.65). The differences among all three techniques were significant. Comparing the normal women with women having only mild fractures, the areas under the ROC curves were 0.79, 0.73 and 0.63 for QCT, L-DXA and PA-DXA, respectively. Significant differences existed between QCT and PA-DXA as well as between L-DXA and PA-DXA. Logistic regression analysis also revealed the highest age-adjusted odds ratios for QCT (3.67; 2.25-5.97) while L-DXA and PA-DXA showed substantially lower odds ratios (2.00; 1.39-2.87, and 1.54; 1.11-2.15, respectively). We conclude that low bone density as measured by QCT, PA-DXA or L-DXA is significantly associated with the prevalence of vertebral fractures. Of the methods studied, QCT of trabecular bone offered the best discriminatory capability. L-DXA proved to be superior to PA-DXA in its diagnostic sensitivity, particularly in women with mild fracture. Mild vertebral fractures are associated with decreased spinal bone density and may be regarded as osteoporotic deformities.

The impact of bone size on broadband ultrasound attenuation

Quantitative ultrasound (QUS) is a simple, inexpensive and radiation-free technique to study skeletal status in osteoporosis. Broadband ultrasound attenuation (BUA) is typically used without normalizing for bone thickness. We investigated the impact of bone thickness on BUA, both in in vitro and in vivo, using commercially available ultrasound scanners (Walker Sonix UBA 575 and 575+). For the study in vitro, we analyzed 12 paired cubes (12 x 12 x 12 mm3) of bovine trabecular bone cut from six "parent" blocks (24 x 12 x 12 mm3). These "parent" blocks showed a fairly homogeneous structure as assessed by conventional radiography. BUA and dual x-ray absorptiometry (DXA) measurements of bone mineral density (BMD) were obtained. The difference between the paired cubes was significant for BUA (p < 0.001), but not for BMD (p > 0.05). The BUA of the "parent" blocks was larger by 32-92% than the average BUA of the corresponding paired cubes, and always less than the sum of the paired cubes (5-34%). BUA thus added up in a complex and nonlinear fashion. Measurements in vivo of the calcaneal bone width demonstrated on radiographs (study in vivo I, 28 postmenopausal women) and CT images (study in vivo II, 17 women) showed a small, positive but not significant correlation with BUA (r2 = 0.13 and r2 = 0.007, p > 0.05). The magnitude of this effect provides further evidence that BUA does not scale linearly with bone size. Our results indicate that simple normalization of BUA data by specifying the results in decibels per megahertz per millimeter units may not be appropriate.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of semiquantitative and quantitative techniques for the assessment of prevalent and incident vertebral fractures

To compare visual semiquantitative (SQ) reading and quantitative morphometry (QM) for assessing prevalent and incident vertebral fractures, radiographs of the thoracolumbar spine were evaluated in 400 (only baseline films) and 335 (baseline and follow-up films) postmenopausal women with osteopenia as defined by a T-score of less than 2 SD below young normals. QM was performed using different cutoff thresholds, and the SQ reading was performed by three radiologists independently. A joint consensus reading of the radiographs by all participating radiologists was used as a reference standard. Our results indicate that the concordance within SQ methods is excellent, and it is higher than that between SQ and QM regardless of the cutoff criteria used. This finding was consistent for the diagnosis of prevalent as well as incident vertebral fractures. For prevalent fractures the use of the 2.5 SD cutoff criterion provided the highest concordance with the consensus reading and with the radiologists' reading, thereby providing high sensitivity (70.23%) with moderate specificity (98.76%) relative to the consensus reading when compared with the 3 SD or 4 SD cutoff criteria. For the diagnosis of incident vertebral fractures the best agreement between our consensus reading and QM was found for an absolute reduction of 6 mm and for a combination of relative and absolute reduction of 15% and 3 mm in vertebral height. The respective sensitivities and specificities for the two criteria were 51%/99.9% and 75.4%/98.9%, respectively. Even though the consensus reading may favor the reader's evaluation over QM, the assessment of prevalent and incident fractures using QM alone may not be sufficiently reliable for detection of vertebral fractures in epidemiological studies and clinical trials. It should be performed principally in conjunction with a trained radiologist or a highly experienced clinician.

The relationship between occupational form and occupational performance: a kinematic perspective

OBJECTIVES

This study examined, through kinematic analysis, the effect of occupational form on reaching performance. The hypothesis was that reaching performance would show an enhanced quality of movement in materials-based occupation (i.e., pick up a pencil and prepare to write one's own name) than in imagery-based occupation (i.e., pretend to pick up a pencil and prepare to sign one's own name) and in exercise (i.e., move the arm forward). It was further hypothesized that imagery-based occupation would elicit better performance than exercise.

METHOD

The reaching performance was measured, using WATSMART (Waterloo Spatial Motion Analysis & Recording Technique), by the variables including reaction time, movement time, number of movement units, total displacement, the amplitude of peak velocity, and percentage of reach in which peak velocity occurred. A repeated-measures counterbalanced research design was used with 37 female college students. Contrast analysis was used to test the hypotheses.

RESULTS

Materials-based occupation elicited enhanced quality of movement performance, as compared with imagery-based occupation and exercise. However, exercise seemed to elicit better performance than imagery-based occupation.

CONCLUSION

The practical implication is that materials-based occupation might be used to elicit enhanced quality of reaching movement in occupational therapy intervention.

Three quantitative ultrasound parameters reflect bone structure

We investigated whether quantitative ultrasound (QUS) parameters are associated with bone structure. In an in vitro study on 20 cubes of trabecular bone, we measured broadband ultrasound attenuation (BUA) and two newly defined parameters--ultrasound velocity through bone (UVB) and ultrasound attenuation in bone (UAB). Bone mineral density (BMD) was measured by dual X-ray absorptiometry (DXA) and bone structure was assessed by microcomputed tomography (microCT) with approximately 80 microns spatial resolution. We found all three QUS parameters to be significantly associated with bone structure independently of BMD. UVB was largely influenced by trabecular separation, UAB by connectivity, and BUA by a combination of both. For a one standard deviation (SD) increase in UVB, a decrease in trabecular separation of 1.2 SD was required compared with a 1.4 SD increase in BMD for the same effect. A 1.0 SD increase in UAB required a reduction in connectivity of 1.4 SD. Multivariate models of QUS versus BMD combined with bone structure parameters showed squared correlation coefficients of r2 = 0.70-0.85 for UVB, r2 = 0.27-0.56 for UAB, and r2 = 0.30-0.68 for BUA compared with r2 = 0.18-0.58 for UVB, r2 < 0.26 for UAB and r2 < 0.13 for BUA for models including BMD alone. QUS thus reflects bone structure, and a combined analysis of QUS and BMD will allow for a more comprehensive assessment of skeletal status than either method alone.

Findings of anomalous pulmonary venous return using MRI

This study represents a preliminary retrospective assessment of the value of spin-echo magnetic resonance imaging (MRI) in detecting and describing total or partial anomalous pulmonary venous return (APVR). MRI was performed in 21 cases of APVR; orthogonal planes were used in all. Of the 21 cases, 19 were classified as total APVR (TAPVR) and two were partial APVR (PAPVR). Of the 19 cases of TAPVR, seven supracardiac, nine cardiac, one infracardiac and two mixed type were noted. The detection rate of each pulmonary vein combined in all three planes was 57% in the right superior pulmonary vein (RSPV), 62% in the left superior pulmonary vein (LSPV), 76% in the right inferior pulmonary vein (RIPV), and 86% in the left inferior pulmonary vein (LIPV). The axial plane was most effective (RSPV: 38%; LSPV: 52%; RIPV: 71%; LIPV: 81%). The coronal plane offered a better detection rate than the axial plane in RSPV (43%) and additional information of bronchial and visceral situs. Imaging of the combined axial and coronal planes was sufficient to evaluate each individual pulmonary vein. The sagittal plane gave no additional information in this respect. Accurate identification of pulmonary venous confluence and anomalous pulmonary venous channel was 95% (20/21). Limitation of echocardiography and and angiocardiography makes cardiac MRI important in assessing pulmonary vein and pulmonary venous confluence. It obviates the need for invasive angiocardiography and is an important supplement to an inadequate echo.

In vitro maturation of human neonatal CD4 T lymphocytes. II. Cytokines present at priming modulate the development of lymphokine production

The development of naive CD4 T cells into type 1 or type 2 Th cells has been extensively analyzed in the mouse. Using neonatal CD4 T lymphocytes as a source of human naive cells, we report that these cells may be induced to differentiate into effector cells producing predominantly Th1 or Th2 cytokines. After 3 days of stimulation with anti-CD3 mAb immobilized on CD32 transfected mouse fibroblasts, followed by 3 days of culture in the presence of IL-2, neonatal cells acquire the phenotypic and functional characteristics of effector cells. Primed cells are enriched in CD45R0hi and CD31- cells, and upon stimulation with PMA+ ionomycin they release significant amounts of IL-2, IFN-gamma, IL-4, IL-5, and IL-10. Addition of exogenous cytokines during the period of activation with anti-CD3 markedly alters the profile of cytokine production by primed cells: 1) IL-2 uniformly enhances Th1 and Th2 cytokine production; 2) IL-4 markedly enhances the release of IL-4, IL-5, and IL-10 and suppresses that of IFN-gamma; 3) IFN-gamma strongly inhibits IL-4 and IL-5 production but slightly enhances IFN-gamma release; 4) IFN-alpha markedly inhibits IL-4 and IL-5 production and increases the production of both IFN-gamma and of IL-10; 5) TGF-beta suppresses IL-4 and IL-5 (and to a lesser extent IL-2) production but has inconsistent effect on IL-10 and IFN-gamma production. These effects of exogenous cytokines are not associated with an alteration of CD31 expression on primed cells.

In vitro maturation of human neonatal CD4 T lymphocytes. II. Cytokines present at priming modulate the development of lymphokine production

The development of naive CD4 T cells into type 1 or type 2 Th cells has been extensively analyzed in the mouse. Using neonatal CD4 T lymphocytes as a source of human naive cells, we report that these cells may be induced to differentiate into effector cells producing predominantly Th1 or Th2 cytokines. After 3 days of stimulation with anti-CD3 mAb immobilized on CD32 transfected mouse fibroblasts, followed by 3 days of culture in the presence of IL-2, neonatal cells acquire the phenotypic and functional characteristics of effector cells. Primed cells are enriched in CD45R0hi and CD31- cells, and upon stimulation with PMA+ ionomycin they release significant amounts of IL-2, IFN-gamma, IL-4, IL-5, and IL-10. Addition of exogenous cytokines during the period of activation with anti-CD3 markedly alters the profile of cytokine production by primed cells: 1) IL-2 uniformly enhances Th1 and Th2 cytokine production; 2) IL-4 markedly enhances the release of IL-4, IL-5, and IL-10 and suppresses that of IFN-gamma; 3) IFN-gamma strongly inhibits IL-4 and IL-5 production but slightly enhances IFN-gamma release; 4) IFN-alpha markedly inhibits IL-4 and IL-5 production and increases the production of both IFN-gamma and of IL-10; 5) TGF-beta suppresses IL-4 and IL-5 (and to a lesser extent IL-2) production but has inconsistent effect on IL-10 and IFN-gamma production. These effects of exogenous cytokines are not associated with an alteration of CD31 expression on primed cells.

Purification of phospholipase C from rat cerebral cortex

Phospholipase C from rat cerebral cortex was purified to homogeneity by use of DEAE Bio-Gel A agarose, hydroxyapatite, and heparin agarose chromatography. The purified phospholipase C (PLC) was purified 622.4-fold and its molecular weight is estimated to be 97,500. We obtained a final specific activity of 3.112 mumol of phosphatidylinositol hydrolyzed/min/mg of protein. It is specific for inositol phospholipids. The purified enzyme has an apparent optimum pH 7.0. Calcium is required for its activity. Western blotting analysis showed that two proteins were recognized by anti-PLC antiserum.

Construction of a modified penicillin-binding protein 2a from methicillin-resistant Staphylococcus aureus and purification by immobilized metal affinity chromatography

The mecA-27r gene, which encodes PBP2a-27r, was modified by site-specific mutagenesis, resulting in replacement of the N-terminal membrane anchor with a short chelating peptide (CP-PBP2a-27r). CP-PBP2a-27r retained the same binding affinity for beta-lactam antibiotics as the wild-type enzyme. Approximately 95% pure CP-PBP2a-27r was recovered in a single step by use of chelating-peptide-immobilized metal ion affinity chromatography.

In vitro maturation of human neonatal CD4 T lymphocytes. I. Induction of IL-4-producing cells after long-term culture in the presence of IL-4 plus either IL-2 or IL-12

Recent studies in the mouse have established that IL-4 and IL-12 direct the development of Ag-stimulated naive CD4 T cells into, respectively, type 2 and type 1 Th cells. We report that prolonged exposure of immunologically naive and unstimulated human neonatal CD4 T cells to IL-4 or to IL-4 plus either IL-2 or IL-12 markedly affects their cytokine production on primary stimulation with PMA and ionomycin. IL-4 induces long-term proliferation of neonatal T cells and after 3 wk of culture these are capable of producing high levels of Th1 (IL-2, IFN-gamma) but no Th2 (IL-4, IL-5) cytokines; IL-4-primed cells are homogenously CD45RO-/RA+ and CD31+. After culture in the presence of IL-4 + IL-2 or IL-4 + IL-12, neonatal T cells are enriched in CD45RO+ and CD31- cells and they can produce Th2 as well as Th1 cytokines. In response to primary stimulation with PMA and ionomycin, cells primed with IL-4 + IL-2 produce IL-4, IL-5, and IL-10 and the same levels of IL-2 and IFN-gamma as IL-4-primed cells. Cells primed with IL-4 + IL-12 produce very high levels of both IL-4 and IFN-gamma but no IL-5. Endogenous IFN-gamma that is detected in primary cultures containing IL-4 + IL-12 does not inhibit, but rather enhances, the ability of the cells to produce IL-4. Further analysis of IL-4 + IL-12-primed cells reveals that IL-4 is mainly produced by CD31- cells and that these cells can trigger B cells to synthesize Ig including IgE. Finally, positively selected CD31+ cells remain CD31+ and are poor IL-4 producers after 3 wk of culture with IL-4 + IL-12, suggesting that these two cytokines promote the selective expansion of the small number of CD31- cells that are present in freshly isolated neonatal CD4 T cells.

In vitro maturation of human neonatal CD4 T lymphocytes. I. Induction of IL-4-producing cells after long-term culture in the presence of IL-4 plus either IL-2 or IL-12

Recent studies in the mouse have established that IL-4 and IL-12 direct the development of Ag-stimulated naive CD4 T cells into, respectively, type 2 and type 1 Th cells. We report that prolonged exposure of immunologically naive and unstimulated human neonatal CD4 T cells to IL-4 or to IL-4 plus either IL-2 or IL-12 markedly affects their cytokine production on primary stimulation with PMA and ionomycin. IL-4 induces long-term proliferation of neonatal T cells and after 3 wk of culture these are capable of producing high levels of Th1 (IL-2, IFN-gamma) but no Th2 (IL-4, IL-5) cytokines; IL-4-primed cells are homogenously CD45RO-/RA+ and CD31+. After culture in the presence of IL-4 + IL-2 or IL-4 + IL-12, neonatal T cells are enriched in CD45RO+ and CD31- cells and they can produce Th2 as well as Th1 cytokines. In response to primary stimulation with PMA and ionomycin, cells primed with IL-4 + IL-2 produce IL-4, IL-5, and IL-10 and the same levels of IL-2 and IFN-gamma as IL-4-primed cells. Cells primed with IL-4 + IL-12 produce very high levels of both IL-4 and IFN-gamma but no IL-5. Endogenous IFN-gamma that is detected in primary cultures containing IL-4 + IL-12 does not inhibit, but rather enhances, the ability of the cells to produce IL-4. Further analysis of IL-4 + IL-12-primed cells reveals that IL-4 is mainly produced by CD31- cells and that these cells can trigger B cells to synthesize Ig including IgE. Finally, positively selected CD31+ cells remain CD31+ and are poor IL-4 producers after 3 wk of culture with IL-4 + IL-12, suggesting that these two cytokines promote the selective expansion of the small number of CD31- cells that are present in freshly isolated neonatal CD4 T cells.

Site-directed mutagenesis of the mecA gene from a methicillin-resistant strain of Staphylococcus aureus

The mecA-27r gene from Staphylococcus aureus 27r encodes penicillin-binding protein 2a (PBP2a-27r), which causes this strain to be methicillin resistant. Removal or replacement of the N-terminal transmembrane domain had no effect on binding of penicillin, but removal of portions of the putative transglycosylase domain (144, 245, or 341 amino acids after the transmembrane region) destroyed penicillin-binding activity. The SXXK, SXN, and KSG motifs, present in all penicillin-interacting enzymes, were found in the expected linear spatial arrangement within the putative transpeptidase region of PBP2a-27r. Alterations of amino acids in all three of these motifs resulted in elimination of penicillin-binding activity, confirming their roles in the interaction with penicillin.

The combined method of transplantation of foetal substantia nigra and stereotactic thalamotomy for Parkinson's disease

Five cases with late Parkinson's disease improved following treatment with a combination of foetal substantia nigra grafts and stereotactic thalamotomy. The average Webster's score decreased from 21 to 11 points. This modified method is simple, safe and effective.

Factors influencing long-term in vivo reproducibility of QCT overtebral densitometry)

OBJECTIVE

We investigated the long-term in vivo reproducibility of quantitative CT (QCT) examinations that were conducted in conformity with a standard and well established methodology.

MATERIALS AND METHODS

The long-term reproducibility in vivo of QCT vertebral densitometry was studied in 12 normal postmenopausal women (mean age 51 years), who underwent four to five examinations over the same 2 year period.

RESULTS

One group of six patients demonstrated good reproducibility with a coefficient of variation (CV) of bone mineral density (BMD) of < 2.4% and were considered "good cases." The other group of six patients showed poor reproducibility with a CV of BMD of > 3.2% and were considered "problem cases." A statistical study of the technical parameters of the QCT examination was performed to determine and correct for the factors that are correlated with reproducibility errors. Analyzing uncalibrated variations in Hounsfield numbers, we found that the surrounding soft tissues such as muscle, aorta, liver, and fat were correlated in both the good and the problem cases. However, only in the good cases did we find that the Hounsfield numbers of the vertebral bodies correlated strongly with the soft tissues and with parameters characteristic of the calibration regression line.

CONCLUSION

Essentially, the calibration procedure appeared to fail in some examinations of the problem cases, causing poor long-term reproducibility. This calibration failure may be related to positioning of the subject in the gantry and to variations in electrical parameters of the X-ray tube. A CV > 1% between the four slopes of calibration for the individual vertebrae measured at the same visit may indicate calibration problems and may suggest the need for repeat scanning.

Vertebral fracture assessment using a semiquantitative technique

The assessment of vertebral fracture by conventional radiography has been refined and improved using either semiquantitative or quantitative criteria. The inter- and intraobserver variability was determined for a semiquantitative visual approach that we routinely use in clinical studies for assessing prevalent and incident vertebral fractures. In addition, the semiquantitative approach was compared with a quantitative morphometric approach. The incidence and prevalence of vertebral fractures were determined in 57 postmenopausal women (age 65-75 years) by three independent observers. The radiographic basis for fracture definitions and the source of interobserver agreement for the semiquantitative technique. We conclude that the semiquantitative approach can be applied reliably in vertebral fracture assessment when performed using well-defined criteria.

[Studies of the spasm-relieving effect of Glycyrrhiza uralensis Fisch.--Aster tataricus L.F. pulvis mixture on the trachea in guinea pigs]

The experiment shows that high concentration of Aster tataricus plus Glycyrrhiza uralensis Fisch. can inhibit the tracheal systoliea caused by histamine, but for tracheal systoliea caused by acetylcholine the inhibition is indistinct. The experiment also shows that Aster tataricus, glycyrrhiza uralensis and Tussilago far fara L. combined have coordinated inhibiting effect on the tracheal systoliea caused by histamine and acetylcholine.

IL-12 induces the production of IFN-gamma by neonatal human CD4 T cells

A major difference between "naive" and "memory" or "effector" Th cells is the spectrum of cytokines that they are capable of producing. After stimulation naive cells produce only IL-2, whereas memory cells produce several cytokines including IFN-gamma and IL-4. Using umbilical cord blood-derived CD4 T cells as a source of naive T cells, we first report that these cells are capable of producing large amounts of IFN-gamma when cultured with low concentrations of IL-12. The response is time- and dose-dependent, and it is observed at the protein and mRNA levels. IL-12 also induces neonatal CD4 T cells to produce lymphotoxin but not IL-2, TNF-alpha, or IL-4. The production of IFN-gamma by IL-12-stimulated neonatal T cells is associated with a small but significant T cell activation evidenced by DNA synthesis and by the expression of the activation markers CD25, CD71, and HLA-DR; moreover, it is inhibited by hydrocortisone, cyclosporin A, and transforming growth factor-beta. The response to IL-12 is enhanced and is much more rapid when CD4 T cells are cultured in the presence of accessory cells or of exogenous IL-1, IL-2, or TNF-alpha. Using a three-step culture system, we next show that IL-12 induces the maturation of resting naive CD4 T cells into cells producing both IL-2 and IFN-gamma but not IL-4 upon stimulation with PMA and ionomycin. Endogenously produced IFN-gamma plays a role in this IL-12-induced T cell maturation, as shown by the inhibitory effect of neutralizing IFN-gamma antibodies. Finally, we show that IL-12 supports the production of IFN-gamma during primary stimulation of neonatal T cells via the CD3/TCR complex by means of either immobilized anti-CD3 mAb or superantigen-coated (Staphylococcus enterotoxin B) fixed L cell transfectants expressing HLA-DR. It is suggested that IL-12 is involved in the selection of Th1 type immune responses.