Intra- and extracellular immunization against HIV-1 infection with lymphocytes transduced with an AAV vector expressing a human anti-gp120 antibody

Recently, we developed a novel anti-HIV-1 approach by transducing an anti-gp120 antibody gene into lymphocytes, resulting in the resistance to HIV-1 infection by the combined intra- and extracellular binding activities of the neutralizing antibody. To extend this study, we improved the co-expression of the heavy and light chains of the Fab105 fragment of the anti-gp120 antibody F105 by using an internal ribosome entry site (IRES) sequence. The Fab105 expression cassette was then cloned into an adeno-associated virus (AAV) shuttle vector, and encapsidated recombinant AAV-Fab105 vectors were produced. The Fab105 antibody gene was shown to be transduced into human lymphocytes by using the recombinant AAV viruses. The transduced lymphocytes were able to produce and secrete the Fab105 fragments, while maintaining their normal morphology, growth rates, and responsiveness to mitogen stimulation. The infection of several primary HIV-1 patient isolates was effectively blocked in the transduced lymphocytes. This study indicates that the combined intra- and extracellular immunization approach may be useful for the treatment of HIV-1-infected patients.

Theory of wear as related to the Björk-Shiley Delrin disc heart valve

BACKGROUND AND AIMS OF THE STUDY

Mechanical wear is an important consideration for the Björk-Shiley Delrin (BSD) heart valve, the disc of which is periodically impacted against the inlet strut by the momentum of the blood flow during closure. Impact wear theory was used in designing experiments as well as establishing theoretical evaluation and projections of wear life.

MATERIALS AND METHODS

The experimental apparatus involved a pivotal hammer device where the striking face could be varied by the inclusion of distinct spherical shapes; the sharper the radius, the higher the contact stress induced. The striking speed could be varied between one and three m/s, and the repetition rate between 2-50 Hz. Blood was simulated with an aqueous 42% glycerol solution. The same wear mechanism was induced on Delrin occluder disc specimens as the one governing the wear observed in Delrin occluder discs of some of the explanted BSD heart valves; thus two wear parameters, c and g, were established for the prediction of wear in BSD implants. The experimental runs were repeated on as many as four simultaneous specimens, for up to 7.5 x 10(7) cycles.

RESULTS

The wear history was found to comprise three distinct regions, corresponding to (a) initial plastic deformations; (b) zero wear; and (c) measurable wear. The zero wear region produced very little change in the contact dimensions, and represented a fatigue threshold to the progress of a wear scar. Procedures for analytical establishment of the zero wear limit are outlined in the paper. Measurable wear was governed by the process of increasing conformance between the repetitively contacting surfaces. The differential equation of wear was then used with the physical parameters c and g previously determined experimentally.

CONCLUSION

The maximum depth of the wear scar after cycling the equivalent of 20 years was predicted to be 278 microns. This value appears to represent a safe dimension for BSD heart valves.

[Determination of paeonol in the root of Cynanchum paniculatum (Bge.) Kitag. by gas chromatography]

A method for the determination of paeonol in the root of Cynanchum paniculatum by macro-reticular resin-GC has been established. The experimental result shows that the standard curve is linear in the detection range and the recovery is 99.42% (RSD = 2.28%, n = 5).

123I-vasoactive intestinal peptide (VIP) receptor scanning: update of imaging results in patients with adenocarcinomas and endocrine tumors of the gastrointestinal tract

Recent data suggest that functional receptors (R) for vasoactive intestinal peptide (VIP) are expressed on various tumor cells. The high-level expression of VIPR on tumor cells provided the basis for the successful use of 123I-labeled VIP for the in vivo localization of intestinal adenocarcinomas and endocrine tumors. We here report an update of our imaging results using 123I-VIP (150-200 MBg/1 microgram/patient) in 169 patients. In patients with pancreatic adenocarcinomas without liver metastases, the primary/recurrent tumor was visualized in 16 of 18 patients (89%) and liver metastases were imaged in 15 of 16 patients. In 11 of 12 patients with colorectal adenocarcinomas, the primary/recurrent tumor (92%) was imaged by 123I-VIP. Also, in 21 of 25 patients, liver metastases (84%); in 3 of 6 patients, lung metastases (50%); and in 4 of 5 patients, lymph-node metastases (80%) were imaged by 123I-VIP. In 10 of 10 patients with gastric adenocarcinomas, the primary/recurrent tumor; in 3 of 4 patients, liver metastases; and in 2 of 2 patients, lymph-node metastases were visualized by 123I-VIP. 123I-VIP localized primary intestinal carcinoid tumors in 15 of 17 patients (88%) and 8 of 10 primary insulinomas (80%). We conclude that the 123I-VIPR scintigraphy localizes intestinal adenocarcinomas and endocrine tumors as well as metastatic tumor sites.

Immediate-early gene responses to different cardiac loads in the ejecting rabbit left ventricle

Clinical and experimental observations in humans and animals have shown that different cardiac adaptations occur in response to different types of hemodynamic overload. However, very little is known about how different hemodynamic loads lead to these different cardiac adaptations. Accordingly, we studied the acute response of ejecting isolated rabbit hearts to independently varied systolic and diastolic mechanical loads at constant coronary perfusion pressure. We studied the combined effects of low end-diastolic volume (EDV) and low systolic ejection pressure (Pej), compared to low EDV and high Pej, high EDU and low Pej, and high EDV and high Pej, on the expression of c-fos, c-jun, and egr-1. Further, although we did not seek to clarify the role of these immediate-early genes in cardiac hypertrophy, we hypothesized that they should not all respond in the same manner to these different mechanical loads. In these ejecting hearts we found that the expression of these immediate-early genes did not all respond alike to the different mechanical loads: both c-fos and egr-1 were strongly induced at both 30 and 60 min. However, at 30 min only c-fos depended on the level of EDV (P = 0.01). Neither c-fos nor egr-1 was influenced by EDV at 60 min. The expression of c-jun was largely insensitive to all loading conditions. We conclude that EDV, independent of Pej, influences the pattern and time course of expression of some immediately-early genes and that these different immediate-early genes do not respond in parallel to changes in cardiac loading.

Climate Change During the Last Deglaciation in Antarctica

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated.

[Gas chromatographic analysis of molinate residue in rice]

We have developed a method for determining molinate residue in rice by gas chromatography. In our study, the rice sample was extracted with acetonewater (1 + 1). After filtering, the filtrate was acidified to pH 3.0-3.5 and re-extracted with petroleum. The extract was cleaned up on a florisil column and followed by analysis with GC/FPD. The linear range of the method was 0-5 micrograms/ml. the detection limit was 0.013 mg/kg for a rice sample of 20 g. The average recoveries of spiked samples ranged from 87.0%-96.7%. The relative deviation standard was less than 5.7%. The experimental verification of this method by extramural departments and its application to determination of rice samples demonstrate that this method is sensitive, reliable and suitable for analysis of molinate residue in rice.

Combined use of 111In-DTPA-D-Phe-1-octreotide (OCT) and 123I-vasoactive intestinal peptide (VIP) in the localization diagnosis of medullary thyroid carcinoma (MTC)

Although serum calcitonin and CEA are sensitive indicators for the presence of medullary thyroid carcinoma (MTC), the localization of tumor sites may be very difficult. In an approach to localize MTC lesions we performed comparative in vivo studies in 12 patients with primary MTC and in 4 patients with suspected recurrent MTC using 123I-VIP (150 MBq/1 microgram) and 111In-DTPA-D-Phe-1-octreotide (111In-OCT; 150 MBq/1 microgram). Despite elevated calcitonin values in all patients with suspected recurrent or metastatic lesions, both ultrasound and computed tomography (CT) were unable to localize a tumor site. 111In-OCT localized the primary tumor in the thyroid gland in 7 of 11 patients (63.5%). In 2 of 4 patients (50%) with suspected recurrent MTC, pathological uptake of 111In-OCT in the mediastinum or liver was demonstrable. In none of the 11 patients did 123I-VIP-receptor scanning indicate primary, recurrent, or metastatic tumor lesions. In vitro binding studies showed an absence of high-affinity VIP receptors in MTC tissue, whereas high-affinity 111In-OCT receptors were present in 4 of 6, and low-affinity 123I-VIP as well as 111In-OCT receptors were present in 6 of 6 MTC tissue samples. We conclude that somatostatin receptor scanning using 111In-OCT may visualize primary MTC, but it has only a low sensitivity in the detection of recurrent disease. The 123I-VIP-receptor scan is not helpful in the localization diagnosis of primary or recurrent MTC.

[Dynamic changes of amino acids in extracellular fluid in rat hippocampus in cases of cerebral ischemia]

OBJECTIVE

To study the changes of excitatory amino acid (EAA) in patients with cerebral ischemia.

METHODS

We observed dynamic changes of EAA in extracellular fluid by intracerebral microdialysis inserted in hippocampus through stereotaxic method with modified Pulsinelli's model of four vessels occlusion.

RESULTS

The concentration of Glu was 5.88 +/- 1.40 and 11.2 +/- 1.5 micromol/L in patients with incomplete cerebral ischemia after 30 minutes and 60 minutes, and the concentration of Asp was 2.72 +/- 0.24 and 4.4 +/- 0.6 micromol/L. The concentration of Glu was 15.1 +/- 1.6 micromol/L and 17.9 +/- 1.6 micromol/L in patients with complete cerebral ischemia after 30 minutes and 60 minutes, and the concentration of Asp was 8.2 +/- 1.0 and 12.1 +/- 1.1 micromol/L. The concentration of Glu and Asp was 1.75 +/- 0.88 micromol/L and 0.24 +/- 0.09 micromol/L in the controls.

CONCLUSIONS

In this study, the concentration of Glu and Asp in patients with cerebral ischemia was significantly increased than in the controls, and the more serious ischemia was, the more release of EAA. It is suggested that Dansen injection can reduce the release of EAA by cerebral cells in case of ischemia.

[Changes in the calcium channels in rat cardiac cells during sepsis]

Changes in the number of calcium channels in two subcellular fractions, the sarcolemma and the light vesicle, of rat cardic cells were studied during sepsis. Sepsis was induced by cecal ligation and puncture (CLP). The results showed that some of the calcium channels in the light vesicle translocated to the sarcolemma during the early sepsis (9 h after CLP) while during the late sepsis (18 h after CLP), some of these in the sarcolemma translocated to the light vesicle. The mechanisms of redistribution of the calcium channels in the sarcolemma and the light vesicle during sepsis was not associated to the phosphorylation of the calcium channels by cAMP dependent protein kinase (PKA), Ca2+/calmodulin dependent protein kinase (PKM) and protein kinase C (PKC). Since beta-adrenergic receptors, muscarinic cholinergic receptors and Na+/K(+)-ATPase were also redistributed during sepsis, it is suggested that the redistribution might be non-specific.

Isolation and characterization of two cDNAs from Atlantic cod encoding two distinct psychrophilic elastases

The cDNAs encoding two different Atlantic cod elastases have been isolated and sequenced. The predicted amino acid sequences revealed two preproelastases, consisting of a signal peptide, an activation peptide and a mature enzyme of 242 and 239 amino acids. Amino acid sequence identity between the two cod elastases was 60.1% and identity with mammalian elastases ranged from 50-64%. The two cod elastases contain all the major structural features common to serine proteases, such as the catalytic triad His57, Asp102 and Ser195. Both cod elastases have a high content of methionine, consistent with previous findings in psychrophilic fish enzymes.

[Antitussive, expectorant and anti-inflammatory effects of rhizoma Cynanchi stauntonii]

Experiments indicated that the ethanol extract and ether extract from Rhizoma Cynanchi Stauntonii showed obvious antitussive and expectorant effects in mice with stomach administration. The antitussive effect of ethanol extract was stronger than the expectorant effect. The water extract showed a certain expectorant effect but no marked antitussive effect with oral administration. Obvious anti-inflammatory effect was observed on croton oil-caused mouse ear swell with intraperitoneal injection.

Appearance of neuronal S-100 beta during development of the rat brain

In addition to being an astroglial protein, S-100 beta is localised in distinct populations of neurons in the adult rat hindbrain. We report, here, the expression of S-100 beta in both neurons and glia of the rat brain during development. Prenatally, S-100 beta immunoreactivity was confined to glial cells close to the germinal zone. After birth, S-100 beta positive glial cells were seen mainly in the brainstem and cerebellum, while only a few were detected in cerebral cortex and hippocampus. The number of S-100 beta containing glial cells increased steadily during the first 2 postnatal weeks after which the adult pattern was attained. No S-100 beta containing neurons were present prenatally. The first S-100 beta containing neurons were seen in the mesencephalic trigeminal nucleus at postnatal day 1 (P1), and in the motor trigeminal nucleus at P3. Neuronal S-100 beta immunoreactivity in other nuclei was mostly attained from the 10th to the 21st postnatal day. The neuronal S-100 beta immunoreactivity was first detected in the cell nuclei during development, then increased in the cytoplasm with ages. A nuclear staining in many immunoreactive neurons persisted until the adult. It usually took 1 to 2 weeks for neuronal S-100 beta to attain the adult staining pattern, i.e., heavy staining of the cytoplasm and processes, after its appearance. The forebrain never contained S-100 beta positive neurons. The S-100 beta is first expressed in glial cells, suggesting it is primarily of the glial origin. Coupled with neurotrophic effects of the protein, the time course of neuronal S-100 beta expression during the critical period of neuronal development implies that it may be involved in neuronal differentiation and maturation.

Evaluation of automatic knowledge acquisition techniques in the diagnosis of acute abdominal pain. Acute Abdominal Pain Study Group

Clinical diagnosis in acute abdominal pain is still a major problem. Computer-aided diagnosis offers some help; however, existing systems still produce high error rates. We therefore tested machine learning techniques in order to improve standard statistical systems. The investigation was based on a prospective clinical database with 1254 cases, 46 diagnostic parameters and 15 diagnoses. Independence Bayes and the automatic rule induction techniques ID3, NewId, PRISM, CN2, C4.5 and ITRULE were trained with 839 cases and separately tested on 415 cases. No major differences in overall accuracy were observed (43-48%), except for NewId, which was below the average. Between the different techniques some similarities were found, but also considerable differences with respect to specific diagnoses. Machine learning techniques did not improve the results of the standard model Independence Bayes. Problem dimensionality, sample size and model complexity are major factors influencing diagnostic accuracy in computer-aided diagnosis of acute abdominal pain.

Phage display of proteases and macromolecular inhibitors

We describe methods for displaying the protease trypsin and the macromolecular protease inhibitor ecotin on the surface of filamentous phage. Our strategy for selecting variant ecotins against target proteases is also described. We believe that the two proteins that have been displayed serve as ideal models for studying molecular recognition in detail. The ability to search efficiently through a large number of variant proteins for desired properties using phage display technology and the in vitro selection methods described opens a new avenue for studying protein-ligand interactions, as well as creating proteins with novel functions.

[Enhancement of antitumor effect of cisplatin on human ovarian cancer by cyclosporin A in vitro and in vivo]

OBJECTIVES

To investigate the enhanced impact of cyclosporin A (CsA) on antitumor activity of cisplatin (DDP) for human ovarian cancer cells.

METHODS

IN VITRO STUDIES

human ovarian adenocarcinoma cells (COC1) and its resistant subline (COC1/DDP) were cultured separately with 4 different preparations: (1) normal saline; (2) CsA alone; (3) DDP alone; (4) DDP plus CsA. After 72 hours, the numbers of tumor cells were counted under microscope. Furthermore, 3H-thymidine incorporation tests were performed on the above 4 systems, and the inhibitory rate of tumor growth were calculated. In vivo studies: normal saline or 2mg/kg of DDP and 5mg/kg of CsA was injected intraperitoneally to nude mice with COC1/DDP xenograft cancer every 3 day for 3 times. The changes of tumor volumes and its pathological appearances were compared before and after treatment.

RESULTS

IN VITRO STUDIES, DDP combined with CsA exhibited a synergistic cytotoxic effect on COC1 and COC1/DDP cells. The decrease of tumor cell numbers reached 24%-36%, 48%-60% of controls respectively. The inhibitory rates of DNA synthesis of these tumor cells, measured by 3H-TdR incorporation tests, were greater in DDP plus CsA group than those in DDP alone group (64.7% 63.9% versus 39.6% 25.1%, P < 0.01). The greater inhibitory rates of CsA+DDP regimen (81.4%) was also shown in vivo studies when compared with DDP alone regimen (49.1%) (P < 0.01). There were significant decreases of tumor cell density and nuclear mitosis in the combined group as compared with that of the DDP alone group (P < 0.01).

CONCLUSIONS

The combination of DDP with 2 micrograms/ml of CsA yields enhancement of antitumor effect on human ovarian cancer. This study suggests that CsA may be used clinically as an antitumor enhancement of DDP for the treatment of ovarian adenocarcinoma.

Barefoot and in a German kitchen: federal parental leave and benefit policy and the return to work after childbirth in Germany

"Since 1979 German federal maternity leave and benefit policy has given women incentives to stay at home and take care of their newborn and youngest children. In 1986 this leave and benefit policy was changed in several ways, turning it into a powerful instrument for delaying mothers' return to work after childbirth.... We estimate post childbirth return to work hazards for women during the federally protected leave protection period and immediately upon completion of this leave period. During the leave mothers are less likely to return to work the longer is the time left in the leave protection period; however, this result cannot be attributed generally to high levels of maternity benefits. When the leave protection period ends, mothers with strong labor force attachment who are still on leave return to their jobs."

Genetic resistance against acute toxoplasmosis depends on the strain of Toxoplasma gondii

The role of the strain of Toxoplasma gondii in genetic control of resistance against acute infection with T. gondii was studied with 2 strains of T. gondii, which differ in their virulence and genotype. Following peroral infection with 10 cysts of the C56 strain, C57BL/6 (H-2b) and C3H/HeN (H-2k) mice died significantly earlier than BALB/c mice (H-2d) mice, although all of the mice eventually died of acute toxoplasmosis from 10 to 23 days after infection. There was no significant difference in time to death between C57BL/6 mice and C3H/HeN mice. In peroral infection with 100 cysts of the less virulent ME49 strain, all C57BL/6 mice died of acute toxoplasmosis from 7 to 10 days after infection. C57BL/6 mice died significantly earlier following infection with the ME49 strain than with the C56 strain, whereas all C3H/HeN mice infected with the ME49 strain survived as did BALB/c mice. These results indicate that genetic control of resistance against acute infection with T. gondii differs depending on the strain of T. gondii.

[Antifebrile and anti-inflammatory effects of radix Cynanchi atrati]

The water extract of Radix Cynanchi Atrati used as intraperitoneal injection has been proved to have an obvious antifebrile++ effect on rat fever caused by 15% yeast suspension hypodermic injection as well as a significant anti-inflammatory effect. But the antiferbrile effect of its ethanol extract is not clear.

Acanthamoeba castellanii contains a ribosomal RNA enhancer binding protein which stimulates TIF-IB binding and transcription under stringent conditions

The intergenic spacer (IGS) of Acanthamoeba castellanii rRNA genes contains repeated elements which are weak enhancers for transcription by RNA polymerase I. A protein, EBF, was identified and partially purified which binds to the enhancers and to several other sequences within the IGS, but not to other DNA fragments, including the rRNA core promoter. No consensus binding sequence could be discerned in these fragments and bound factor is in rapid equilibrium with unbound. EBF has functional characteristics similar to vertebrate upstream binding factors (UBF). Not only does it bind to the enhancer and other IGS elements, but it also stimulates binding of TIF-IB, the fundamental transcription initiation factor, to the core promoter and stimulates transcription from the promoter. Attempts to identify polypeptides with epitopes similar to rat or Xenopus laevis UBF suggest that structurally the protein from A.castellanii is not closely related to vertebrate UBF.

Planned relaparotomy vs relaparotomy on demand in the treatment of intra-abdominal infections. The Peritonitis Study Group of the Surgical Infection Society-Europe

OBJECTIVE

To define the role of planned relaparotomy (PR) in the treatment of intraperitoneal infection, compared with that of relaparotomy on demand (RD).

DESIGN

Case-control study on the basis of a prospective multicenter cohort analytic study. Statistical evaluation was done by the McNemar test for qualitative data and the Wilcoxon matched-pairs signed rank test for qualitative data.

SETTING

Eighteen hospitals of different care levels in Austria, Germany, and Switzerland.

PATIENTS

Thirty-eight of 42 patients with intra-abdominal infections who underwent PR were matched for APACHE II (Acute Physiology and Chronic Health Evaluation II) score, age, cause of infection, site of origin of peritonitis, and the ability of the surgeon to securely eliminate the source of infection with 38 patients taken from a cohort of 278 undergoing RD.

INTERVENTIONS

Planned relaparotomy was defined as at least one relaparotomy decided on at the time of the first surgical intervention; RD, relaparotomy indicated by clinical findings.

MAIN OUTCOME MEASURES

Mortality and incidence of postoperative multiple organ failure and infectious complications.

RESULTS

There was no significant difference in mortality between patients treated with PR (21%) or RD (13%). Postoperative multiple organ failure as defined by a Goris score of more than 5 was more frequent in the group of patients undergoing PR (50%), compared with the group undergoing RD (24%) (P = .01), as were infectious complications (68% vs 39% [P = .01]). Infectious complications were due to more frequent suture leaks (16% vs 0% [P = .05]), recurrent intra-abdominal sepsis (16% vs 0% [P = .05]), and septecemia (45% vs 18% [P = .05]) in the PR vs the RD groups. The incidence of other complications was not different in the two groups.

CONCLUSIONS

Until larger prospective studies are available, the indication for PR should be evaluated with caution.

S-100 beta has a neuronal localisation in the rat hindbrain revealed by an antigen retrieval method

The localisation of S-100 in mammalian CNS neurons has been under debate for more than two decades. We address the question with two polyclonal and two new monoclonal antibodies. The specificity and the distribution in rat brain is based on an antigen retrieval method. We present evidence that aldehyde fixatives mask S-100 beta in neurons, and that the immunoreactivity is retrieved after trypsinisation. Neuronal S-100 beta is also detected in unfixed and ethanol fixed sections. The neuronal immunoreactivity is partly solubilised from unfixed tissue sections with 2.5 mM EDTA and is completely extracted with 2.5 mM EDTA and 1% Triton X-100. Most of the glial S-100 beta is washed out from unfixed tissue sections with saline. S-100 beta has distinct distribution in neurons of the hindbrain, i.e., the brainstem and cerebellum, but is not observed in the forebrain. One of the monoclonal antibodies immunostained neither neurons nor glia when it had been absorbed with S-100 crosslinked to nitrocellulose membranes. The distribution of neuronal S-100 beta differed from that of other neuronal calcium binding proteins, such as calbindin and parvalbumin. It was confined mainly to cholinergic neurons of the hindbrain. The presence of S-100 beta in distinct neuronal populations may indicate neurotrophic effects of S-100 beta. The notion is supported by the capability of S-100 to cause neurite outgrowth in vitro.

S-100 beta immunoreactivity in neurones of the rat peripheral sensory ganglia

S-100 beta, which is capable of exerting neurotrophic effects on cultured neurones and promoting the survival of motor neurones in vivo, has recently been found in distinct neurones of the rat hindbrain. Here we report that S-100 beta, as well as being present in satellite and Schwann cells, is also present in neurones of sensory ganglia (dorsal root ganglion, trigeminal, petrosal, jugular and nodose ganglia) but absent from neurones of the superior cervical ganglion. In the sensory ganglia, many neurones were immunoreactive, while the staining intensity varied among the neurones. Neuronal S-100 beta appeared in developing rats as early as postnatal day 1. No immunoreactive neurones were observed in the superior cervical ganglion during development. The results are suggestive of selective neurotrophic effects of S-100 beta.

Conformation of parathyroid hormone antagonists by CD, NMR, and molecular dynamics simulations

The conformation of two highly potent parathyroid hormone (PTH) antagonists was investigated in water/2,2,2-trifluoroethanol mixtures. The two peptides are derived from the sequence (7-34) of PTH and of PTH-related protein (PTHrP) and have a D-Trp replacing Gly in position 12. In the analogue derived from PTHrP, Lys11 was replaced by Leu to remove the residual agonist activity. The study was conducted by CD and two-dimensional proton magnetic resonance spectroscopy, and the nuclear Overhauser effects found were utilized in restrained distance geometry and molecular dynamics simulations. Both peptides adopt a helical C-terminal conformation, which seems more stable in the case of the PTHrP analogue. A type II' beta-turn centered around D-Trp12 and Lys13 is present in both structures.

Phosphorylated and non-phosphorylated neurofilament proteins: distribution in the rat hippocampus and early changes after kainic acid induced seizures

The regional distribution of neurofilament proteins in the rat hippocampus and their early changes after kainic acid induced seizures were investigated immunocytochemically with antibodies against light weight neurofilament, phosphorylated and non-phosphorylated heavy weight neurofilament. The light weight and non-phosphorylated heavy weight neurofilaments were distributed more unevenly than the phosphorylated neurofilament. The perikarya and processes of pyramidal cells in the CA3 field contained the highest light weight and non-phosphorylated heavy weight neurofilaments, while the perikarya of granule cells contained only few light weight neurofilament and the perikarya of CA1 pyramidal cells were even devoid of immunoreactivity of both light and heavy weight neurofilaments. The fiber staining of the light weight and non-phosphorylated heavy weight neurofilaments, especially the former, was less in the CA1 field and molecular layer of dentate gyrus. The phosphorylated neurofilament immunoreactivity was identified only in axons. Mossy fibers, the axons of granule cells, contained the light weight and phosphorylated heavy weight neurofilaments, but not the non-phosphorylated neurofilament. Seven days after the kainic acid induced seizures, the phosphorylated neurofilament staining was greatly reduced in the CA1 and inner molecular layer of the dentate gyrus, probably resulting from the axonal degeneration of the Schaffer collaterals and the commissural/associational fibers. Furthermore, the nonphosphorylated neurofilament appeared in the mossy fibers of the CA3 stratum lucidum, which normally do not express such immunoreactivity. The results indicate that the neurofilaments are altered following the neuronal degeneration and postlesional plasticity caused by the kainic acid administration. Therefore, the examination of various phosphorylated neurofilaments may offer a comprehensive understanding of major hippocampal pathways, axonal plasticity and the possible roles of neurofilaments in the hippocampus following excitotoxic insults.

Biochemical characterization of a human band 4.1-related protein-tyrosine phosphatase, PTPH1

PTPH1 is a human protein-tyrosine phosphatase with homology to the band 4.1 superfamily of cytoskeleton-associated proteins. Here, we report the purification and biochemical characterization of this enzyme from baculovirus-infected insect cells. The purified protein exhibited an apparent M(r) of 120,000 on SDS gels. The native enzyme dephosphorylated both myelin basic protein (MBP) and reduced, carboxamidomethylated, and maleylated lysozyme (RCML) but was over 5-fold more active on MBP. The Km values for the two substrates were similar (1.45 microM for MBP and 1.6 microM for RCML). Phosphorylation of PTPH1 by protein kinase C in vitro resulted in a decrease in Km but had no effect on Vmax. Removal of the NH2-terminal band 4.1 homology domain of PTPH1 by limited trypsin cleavage stimulated dephosphorylation of RCML but inhibited its activity toward MBP. The dephosphorylation of RCML by full-length PTPH1 was enhanced up to 6-fold by unphosphorylated MBP and increasing ionic strength up to 0.2 M NaCl, whereas trypsinized preparations of PTPH1 containing the isolated catalytic domain were unaffected. These results suggest that in addition to a potential role in controlling subcellular localization, the NH2-terminal band 4.1 homology domain of PTPH1 may exert a direct effect on catalytic function.

Immobilized liposome chromatography for analysis of interactions between lipid bilayers and peptides

Liposomes were sterically immobilized in gel beads to be used for isocratic chromatographic analysis of interactions between lipid bilayers, amino acids, and water-soluble peptides. Tryptophan was more retarded on the immobilized liposomes than were other amino acids, and peptides with C-terminal cysteine were much more retarded than were peptides with serine or aminobutyric acid instead of the cysteine. Peptide sequences could affect the peptide-liposome interactions. For peptides corresponding to polypeptide segments of a membrane protein, the human red cell glucose transporter (Glut1), the retention volumes increased with decreasing water-to-oil transfer free energy of the peptides and were related to the transfer free energy distribution within the peptides as shown by hydropathy plots and to the presence of cysteine. Among these peptides, the partially hydrophobic peptides 125GRFIIGVYCG134 and 201CIVLPFCPES210 and the hydrophilic peptide 421CFQYVEQLC429 were most strongly retarded on immobilized phosphatidylcholine liposomes. The results indicated that the peptide-liposome interactions were mainly of hydrophobic nature and that the structure of the interfacial head-group region of the lipid bilayers was important.

[Alteration of phospholamban phosphatase activity associated with cardiac sarcoplasmic reticulum during sepsis in rats]

In the present study, rat cardiac sarcoplasmic reticulum (SR) phospholamban (PLB) phosphatase was partially purified by chromatography on DEAE-Sephacel. This PLB phosphatase was indentical to phosphatase-1. It was shown on electrophoresis of SDS-PAGE autoradiography that the PLB phosphatase in rats during early sepsis (ES) depressed dephosphorylation of substrates (32P-phosphorylase a and 32P-SR). However, dephosphorylation of the substrates by the partially purified phosphatase during late sepsis (LS) was same as that in control rats. The partially purified PLB phosphatase activity in ES rats was significantly decreased, but showed no change in LS rats. The results above were confirmed by a studing of the substrate concentration (enzyme concentration, time)--enzyme reaction velocity curve in showing that both affinity and maximum initial velocity (Vmax) of the phosphatase in the ES rats were decreased, but had no change in those in the LS rats.

Low-power phase conjugation in push-pull azobenzene compounds

Push-pull azobenzene compounds were synthesized by the diazocoupling reaction, and low-power phase conjugation of azobenzene-compound-doped poly(methyl methacrylate) films was studied with a He-Ne laser at 632.8 nm. It is shown that this kind of polymer has appreciable third-order optical nonlinearity, with a chi((3)) of approximately 10(-4) esu in the tail of absorption.

[Study on effect of polysaccharides of ginseng on peripheral blood mononuclear cell induced interleukin-2 production and activity of its receptors in vitro]

To study the effect of polysaccharides of Ginseng (PSG) on cellular-immunity from healthy subjects and patients of kidney disease, the peripheral blood mononuclear cell (PBMC) induced interleukin-2 (IL-2) were assayed in vitro. It was found that the PSG could prommote the PBMC induced IL-2 in the healthy subjects and patients with kidney diseases and was dose-dependent. This study revealed that PSG was worthwhile to be further studied as an approach of biological responsive modifier therepy in treating human immunodeficiency diseases.

Immobilized-liposome chromatographic analysis of drug partitioning into lipid bilayers

The chromatographic retardation of drugs on a gel bed with immobilized liposomes was shown to correlate with the absorption of the drugs through epithelial cell layers, which is related to drug partitioning into the lipid bilayers of cell membranes. The capacity factors were divided by the lipid concentration (mM) in the gel bed to obtain specific capacity factors, Ks. The logarithm of the octanol-water distribution ratios showed a linear correlation with log Ks, whereas the logarithm of the apparent permeability coefficients in epithelial cell monolayers and the absorption of drugs orally administered in humans (data from other laboratories) increased over the interval 0 < log Ks < 1 and attained a saturation level in the interval 1 < log Ks < 3. Immobilized-liposome chromatography may be applicable for prediction of drug uptake through epithelial cell membranes.

Immobilized proteoliposome affinity chromatography for quantitative analysis of specific interactions between solutes and membrane proteins. Interaction of cytochalasin B and D-glucose with the glucose transporter Glut1

An affinity gel bed was prepared by reconstitution of a transmembrane protein, the human red cell glucose transporter (Glut1), followed by steric immobilization of the proteoliposomes in small and rigid gel beads by freeze-thawing. The specific interactions between the reconstituted Glut1, the transport inhibitor cytochalasin B (CB), and the transported solute D-glucose were analyzed by isocratic chromatography of CB on the Glut1-proteoliposome gel bed. Specific retardation of CB which decreased upon inclusion of the competitor D-glucose in the eluent was observed on-line. The equilibrium constants for CB and D-glucose interaction with Glut1 (Kd 1.5 x 10(-7) M and 67 mM, respectively) obtained by use of equations derived for the affinity chromatographic analysis were consistent with values obtained by others by conventional methods. Effects of liposome composition, pH, and time on the CB binding activity of Glut1 were studied. Reconstitution of a membrane protein into a lipid environment and steric immobilization of the proteoliposomes favor retention of the protein activity. Immobilized proteoliposome affinity chromatography (IPAC) is a novel, powerful method for analysis of interactions between membrane proteins and solutes.

Isolation of a high affinity inhibitor of urokinase-type plasminogen activator by phage display of ecotin

Ecotin, a serine protease inhibitor found in the periplasm of Escherichia coli, is unique in its ability and mechanism of inhibiting serine proteases of a broad range of substrate specificity. However, although the catalytic domain of human urokinase-type plasminogen activator (uPA) has 40% identity to bovine trypsin and the substrate specificities of these two proteases are virtually identical, ecotin inhibits uPA almost 10,000-fold less efficiently than trypsin. Ecotin was expressed on the surface of filamentous bacteriophage (ecotin phage) to allow the isolation of more potent inhibitors of uPA from a library of ecotin variants. The 142-amino acid inhibitor was fused to the C-terminal domain of the M13 minor coat protein, pIII, through a Gly-Gly-Gly linker and assembled into phage particles. The ecotin phage were shown to react with anti-ecotin antibodies, revealing a stoichiometry of approximately one ecotin per bacteriophage. The ecotin displayed on the surface of phage inhibited trypsin with an equilibrium dissociation constant of 6.7 nM, in close approximation to that of free ecotin, indicating that phage-associated ecotin is correctly folded and functionally active. Reactive-site amino acids 84 and 85 of ecotin were then randomized and a library of 400 unique ecotin phage was created. Three hundred thousand members of the library were screened with immobilized uPA and subjected to three rounds of binding and in vitro selection. DNA sequence analysis of the selected ecotin phage showed that ecotin M84R/M85R predominated while ecotin M84R, M84K, and M84R/M85K were present at a lower frequency. The four ecotin variants were overexpressed and purified and their affinities toward uPA were determined. Each of the selected ecotin variants exhibited increased affinity for uPA when compared to wild-type ecotin with ecotin M84R/M85R showing a 2800-fold increase in binding affinity.

Diagnostic scores for acute appendicitis. Abdominal Pain Study Group

OBJECTIVE

To assess the value of predictive scores in the diagnosis of acute appendicitis.

DESIGN

Multicentre evaluation with a prospective database.

SUBJECTS

1254 patients with acute abdominal pain.

SETTING

6 departments of surgery, Germany.

INTERVENTIONS

To measure the performance of 10 scores on one database using standardised criteria and to compare the results with published data.

MAIN OUTCOME MEASURES

The ability of a score to fulfill standardised criteria: an initial negative appendicectomy rate of 15% or less, a potential perforation rate of 35% or less, an initial missed perforation rate of 15% or less, and a missed appendicitis rate of 5% or less.

RESULTS

Reevaluation of the published data showed that the Alvarado score fulfilled all four criteria and the Lindberg, the Fenyö and the Christian scores fulfilled two criteria each. If applied to our database (acute abdominal pain, suspected appendicitis), none of the scores fulfilled any of the given criteria, even if the cut-off point was varied systematically. There were significant differences among the scores.

CONCLUSIONS

The original published data seemed to comply with our standardised criteria but evaluation of the scores on our database resulted in poor performances for all of them. Published data seem to be optimistically biased whereas our evaluation gives more realistic estimates of the routine performance in different clinical environments. Further well designed large scale trials are needed to investigate the clinical benefit of diagnostic scoring in acute appendicitis.

[A study on the mechanism of the cardiac adenylyl cyclase activity alteration in septic rats]

The present work showed that cardiac sarcolemmal (SL) adenylyl cyclase (AC) and purified AC maximal activity of septic rat (cecal ligaation and puncture, CLP) were significantly increased during the early sepsis (ES, CLP 9 h) but decreased in the late sepsis (LS, CLP 18 h). Similar alterations were observed in cardiac sarcolemmal protein kinase C (PKC) activity. Sensitization and desensitization of rat SL adenylyl cyclase during ES and LS were respectively correlated with activition and inhibition of PKC. The biphasic changes of AC and PKC were independent of beta- and alpha 1-adrenergic receptor systems. The rat cardiac sarcolemmal PKC activation and AC sensitization during ES is related to M-cholinergic receptor system. The system, however, is not involved during the LS PKC inhibition and AC desensitization.

Electrocardiographic interactions between pinacidil, a potassium channel opener and class I antiarrhythmic agents in guinea-pig isolated perfused heart

1. Drugs that shorten action potential duration could decrease the Na-channel blocking effect of class I antiarrhythmic agents by reducing the availability of Na channel in the inactivated state. 2. This hypothesis was tested in guinea-pig perfused heart, measuring the surface ECG effects of three class I drugs endowed with different binding kinetics (15 microM mexiletine, 10 microM quinidine and 3 microM flecainide) in the presence of increasing concentrations of pinacidil (10 microM, 30 microM, 50 microM), a potassium channel opener that shortens action potential duration. 3. The ECG parameters measured were: the QRS interval, i.e. the intraventricular conduction time; the JT interval, which reflects the duration of ventricular repolarization; the ratio between JT peak (the time from the end of QRS and the peak of T wave) and JT interval, which quantifies changes in the morphology of the T wave. 4. At the concentrations tested all the antiarrhythmic drugs widened the QRS complex by 55-60%. Flecainide did not significantly change JT interval, but quinidine prolonged and mexiletine shortened it. Mexiletine also decreased the JT peak/JT ratio. Pinacidil by itself decreased the JT interval and the JT peak/JT ratio in a dose-dependent way, but did not affect QRS duration. 5. In the presence of fixed antiarrhythmic drug concentrations, however, pinacidil decreased the QRS prolongation induced by mexiletine (-17%) and quinidine (-8%), but not that induced by flecainide: this effect was already maximal at the lower concentration tested (10 microM) and there was no relationship between pinacidil-induced JT shortening and QRS changes. To explain this unexpected result it has been supposed that, at the driving frequency used (4 Hz), myocardial cells were partially depolarized and that pinacidil could repolarize them, thus decreasing the number of inactivated Na channels and the effects of drugs that (mainly or partly) block the channels in the inactivated state. In agreement with this hypothesis, an additional series of experiments carried out with 15 microM mexiletine at a lower stimulation rate (2 Hz) showed only a negligible loss of QRS effect (- 2.3%) at any pinacidil concentration.6. Flecainide, but not quinidine and mexiletine, antagonized the JT shortening induced by pinacidil;furthermore, no drug modified the JTp/JT decrease induced by pinacidil.7. These results indicate that: (a) an antagonism between class I antiarrhythmic drugs and pinacidil is possible; (b) mexiletine is the most involved among the drugs tested; (c) the interaction is not related to pinacidil-induced repolarization shortening, but probably to changes in membrane resting potential. The possible clinical implications need to be defined.

[Prognostic factors in curative resection of stomach carcinoma. A uni- and multivariate analysis]

The TNM system, including tumor infiltration (T category), lymph node infiltration (N category) and metastasis (M category), is a well-established system of prognostic factors. To evaluate the prognostic importance of patient characteristics and tumor parameters 5 clinical and 13 pathological factors were analyzed. Data on 200 consecutive patients with histologically verified stomach cancer were prospectively recorded using a standardized form. In the subgroup with curative resection (R0, n = 108) a uni- and multivariate analysis was performed with respect to 5-year survival. In the univariate analysis statistical significance was demonstrated for the following factors: tumor size, tumor localization, T category, N category, number of infiltrated lymph nodes infiltrated, lymph node compartments, tumor stage, lymph node ratio: infiltrated/inspected. Multivariate analysis, taking into consideration the interaction between prognostic factors, revealed only two factors as statistically significant: number of infiltrated lymph nodes and tumor size. Our results and those in the literature indicate that the infiltration of lymph nodes is the most relevant prognostic factor. In addition to the TNM system the number of infiltrated lymph nodes seems to be of prognostic importance.

[Antitussive, expectorant and anti-asthmatic effects of Cynanchum glaucescens (Decne.) Hand. -Mazz]

The water, ethanol and ether extracts from Cynanchum glaucescems administrated orally showed significant antitussive effect in ammonia-induced cough model in mice. The water and ethanol extracts had obvious expectorant effect. The filtered solution of water decoction injected intraperitoneally could effectively prevent guinea pigs from asthma induced by acetulcholine and histamine mixture, and also inhibit the ear inflammation in mice caused by croton oil. All these effects showed close dose-effect relationship.