Cephalosporin C production by a highly productive Cephalosporium acremonium strain in an airlift tower loop reactor with static mixers

The production of cephalosporin C (CPC) and its precursors penicillin N (PEN N), deacetoxycephalosporin C (DAOC) and deacetylcephalosporin C (DAC), with a highly productive strain of Cephalosporin acremonium, was investigated in an 80-1 airlift tower loop reactor with four static mixer modules (Type SMV, Sulzer) (ATLRM) on a complex medium containing 50 g l-1 peanut flour (PF). The most important key parameters such as glucose concentration and cell mass concentration were monitored during a fed-batch cultivation process. The concentrations of products CPC, PEN N, DAOC an DAC were determined on line by HPLC. The influences of four motionless mixers on the dissolved oxygen concentration (DOC), oxygen transfer rate, the cell growth and the CPC production, as well as the reactor performance, were evaluated. The results were compared with the performance of an airlift tower loop reactor (ATLR) without static mixers as well as with a stirred tank reactor (STR). A comparison of cultivations in the ATLRM and ATLR with 50 g l-1 PF indicates that the obtained maximal CPC concentration and the (CPC + DAC + DAOC) concentration were 7% and 22% higher in the ATLRM (4.96 and 7.46 g l-1) than in the ATLR (4.63 and 6.13 g l-1) respectively. The maximal CPC volumetric productivity in the ATLRM (55.1 mg l-1 h-1) was also considerably higher than that in the ATLR (48.5 mg l-1 h-1). The specific power input was reduced from 2.36 to 1.5 kW m-3, the specific productivity pertaining to the power input was improved from 1.96 to 3.31 g W-1. On the other hand, cultivation in the ATLRM had a lower maximum CPC concentration and volumetric productivity than those in STR (7.2 g l-1 and 71.2 mg l-1 h-1) with the same medium due to the lower shear stress levels and the lower specific power input (1.5 vs. 3.0 kW m-3); but the specific power imput-based yield coefficient was in the ATLRM (3.31 g W-1) higher than in the STR (2.40 g W-1). By increasing the amount of PF, it was possible to enhance the CPC concentration and volumetric productivity in the STR. However, the performance of the ATLRM was limited to using a medium containing maximal 50 g l-1 PF because of the high viscosity of the medium, the limited energy input and thus the limited oxygen supply.

Decolorization of industrial effluents containing reactive dyes by actinomycetes

Actinomycete strains have been identified which decolorize effluents containing different types of reactive dyes. Adsorption of anthraquinone, phthalocyanine and azo dyes to the cells of some of the strains resulted in the decolorization of the effluents, but no degradation of the dyes was observed. In contrast, effluents containing an azo-copper complex and a formazan-copper complex dye were almost completely decolorized by several of the strains without adsorption to the cells. The observed changes in the visible spectra indicated a degradation during incubation with the strains.

The study of relationships between the damage of visual function and hemorrheology, ocular rheography, as well as other related factors in patients with primary open angle glaucoma (POAG)

Researches of glaucoma visual function damage, hemorheology, ocular rheography and other related multiplex factors, with computed multifactorial stepwise regression analysis, indicate that the elevation of intraocular pressure (IOP) is not the only factor to induce visual impairment. POAG patients are shown to have markedly reduced diastolic perfusion pressure in ophthalmic artery, besides prolonged filling time of the retinal artery and vein, diminished erythrocyte deformability and increased platelet adhesion rate. The characteristic of ocular rheographic changes in POAG patients of controlled IOP suggest that the abnormal changes of hemorheology be responsible for the damage of visual function. The abnormal changes of plasma viscosity, blood apparent viscosity, blood viscoelasticity, hematocrit, mean red cell volume etc could be found in addition to the reduction of PO2, SO2% and trace elements (Cr, Zn, Mg, Fe) in patients with POAG. Computed multiply stepwise regression analysis and Bayes discrimination were made among the deteriorate rate of quantitative visual field and 28 factors from the combined investigation. Only the hemorrheological index could be introduced into the multiply regression equations. The more the damage of visual function in POAG patients, the more accurate the discriminatory effect. Based upon the results, and the reports of articles published as well as the search of 1982-1989 Compact Combridge MEDLINE Medical data base, the new clinical concept could be presented that POAG might belong to the scope of blood hyperviscosity syndromes. When IOP elevation and the decrease of ocular artery pressure existed, the damage of visual function in POAG patients should be deteriorated.

Cloning and characterization of the human GnRH receptor

A cDNA encoding the human GnRH receptor (GnRHR) has been cloned and functionally expressed in both Xenopus oocytes and COS-1 cells. The 2160 bp cDNA encodes a 328 amino acid protein with a predicted amino acid sequence that is 90% identical to that of the mouse GnRHR (Tsutsumi et al. (1992) Mol. Endocrinol. 6, 1163-1169). Injection of synthetic RNA transcript into oocytes led to the development of a depolarizing response to agonists when assayed by voltage-clamp electrophysiology. Consistent with the expression of a mammalian GnRHR, the response was blocked by GnRH antagonists. Following expression of the human GnRHR in COS-1 cells, agonists and an antagonist displaced [125I]GnRH agonist from membrane isolates with nanomolar range dissociation constants similar to those described for displacement from human pituitary membranes. Transfected COS-1 cells manifested a GnRH-stimulated increase in phosphoinositol turnover, with an EC50 of approximately 3 nM, which was inhibited by GnRH antagonists. Northern blot analysis revealed a single band of approximately 4.7 kb expressed in human pituitary which was not detected in testis. The predicted structure of the human GnRHR is similar to that previously reported for the mouse receptor. Although the mammalian GnRHR is a seven transmembrane domain receptor, it differs from other G-protein coupled receptors in several respects, most notably the lack of a cytoplasmic C-terminal domain. The present study demonstrates that the cDNA isolated encodes the human GnRHR and suggests that several unique features conserved among mammalian GnRHRs may be essential for receptor function and/or regulatory control.

Ca(2+)-dependent stimulation of retinoblastoma gene product phosphorylation and p34cdc2 kinase activation in serum-stimulated human fibroblasts

In serum-deprived human fibroblasts IMR-90 and WI-38 cells, the addition of fetal calf serum or basic fibroblast growth factor stimulates DNA synthesis in an extracellular Ca(2+)-dependent manner; the effect of serum on [3H]thymidine incorporation into DNA is 4-16-fold greater at 2.0 mM CaCl2 as compared with that at 0.03 mM CaCl2. By contrast, in SV40 virus-transformed WI-38 (SV-WI-38) cells DNA synthesis is essentially independent of the extracellular calcium concentration ([Ca]out) and serum growth factors. To explore the role of Ca2+ in mitogenic signal transduction through G1 to S phase cell cycle progression, we studied and compared the effect of [Ca]out on phosphorylation of RB protein, the product of a tumor suppressor retinoblastoma gene. In IMR-90 and WI-38 cells, serum or basic fibroblast growth factor induces an increase in the amount of hyperphosphorylated forms of RB protein in a manner strictly dependent on [Ca]out. In sharp contrast, in SV-WI-38 cells, the extent of RB phosphorylation is little affected by [Ca]out or the presence or absence of serum growth factors. In addition, potent calmodulin antagonists W-7 and calmidazolium, but not an inactive analogue W-12 or W-5, strongly inhibit serum-induced increases in DNA synthesis and RB phosphorylation in IMR-90 and WI-38 cells, whereas in SV-WI-38 cells, the inhibitory effect is much more limited. Under the same treatment conditions, we measured histone H1 kinase activity associated with anti-p34cdc2 immunoprecipitate and found that the serum-induced increase in p34cdc2 kinase activity is strongly dependent on [Ca]out and is potently inhibited by the active calmodulin antagonists in IMR-90 and WI-38 cells, but not in SV-WI-38 cells. In IMR-90 cells that have been incubated with serum in 0.03 mM [Ca]out for 24 h, restoration of [Ca]out to 2.0 mM results in initiation of DNA synthesis after 13 h and concomitant increases in RB phosphorylation and p34cdc2 histone H1 kinase activity. These results suggest that in human fibroblasts, Ca2+/calmodulin regulates the signaling cascade leading to cdc2 kinase activation, RB protein phosphorylation, and DNA synthesis and that this Ca(2+)-dependent regulation is abrogated in SV40-transformed cells.

Effects of fire ant venom alkaloids on platelet and neutrophil function

About 95% of venom of the imported fire ant Solenopsis invicta is composed of dialkyl piperidines. These alkaloids produce a distinct pustule at the site of injection. The formation of this pustule may involve the activation of platelets and neutrophils. The purpose of this paper was to characterize the effects of fire ant venom alkaloids (FAVA) on certain physiological and biochemical functions of human platelets and neutrophils. In platelets, FAVA caused a rise in intracellular [Ca2+], secretion of dense granules as measured by ATP release, and aggregation as measured by light transmission through a suspension of platelets. Aggregation response was less complete with FAVA than with thrombin or PAF. However, secretion response was greater with FAVA than thrombin. One of our most significant findings was that pretreatment of platelets with subthreshold concentrations of FAVA produced enhanced PAF-induced increase in [Ca2+]cyt, suggesting that synergism between the two agonists might play an important role in the physiological response to FAVA. In neutrophils, FAVA produced a rise in intracellular [Ca2+] and aggregation, although the responses were more moderate than those observed in platelets. These results suggest that FAVA activation of platelets and neutrophils may occur in vivo as a response to stings by red fire ants.

Novel expression of gastrin (cholecystokinin-B) receptors in azaserine-induced rat pancreatic carcinoma: receptor determination and characterization

Many reports have emphasized the role of gastrin as a growth factor for normal gastrointestinal mucosa and gastrointestinal cancers. Recent studies have pointed out that this peptide acts also as a growth factor for the pancreatic cancer cell line AR42J. This effect is mediated by gastrin [cholecystokinin (CCK)-B] receptors. In the present study, we investigated gastrin (CCK-B) receptor expression in the azaserine-induced rat pancreatic carcinoma DSL-6, comparing it to normal rat pancreas, and we also characterized CCK receptor subtypes in this tumor. The results showed that there is extensive gastrin binding to the DSL-6 pancreatic carcinoma. No evidence of specific gastrin binding to normal pancreas was found. Analysis of the ability of gastrin-17-I to inhibit 125I-gastrin-I binding demonstrated that gastrin bound to a single class of receptors with a Kd of 0.21 +/- 0.04 nM and a binding capacity of 184 +/- 29 fmol/mg protein. 125I-Gastrin-I binding was inhibited by the specific CCK-B receptor antagonist L365,260 approximately 40 times more effectively than by the specific CCK-A receptor antagonist L364,718. Analysis of the ability of cholecystokinin octapeptide (CCK-8) to inhibit 125I-Bolton-Hunter-CCK-8 binding revealed two CCK binding sites, i.e., a high affinity site and a low affinity site. The observed binding affinities of CCK-8 were then introduced into the computer analysis of the dose-inhibition curve of the ability of gastrin-17-I to inhibit binding of 125I-Bolton-Hunter-CCK-8, which was significantly better fit by a three-site model than by a two-site model. The three sites meet the criteria for CCK-B, high affinity CCK-A, and low affinity CCK-A receptors. The binding capacity of CCK-B receptors constitutes 34% of the total high affinity CCK binding sites. This study demonstrated that DSL-6 pancreatic carcinoma expresses three subtypes of CCK receptors. Gastrin (CCK-B) receptors, which were not detected in normal rat pancreas, constitute about one third of the total high affinity CCK receptors. We suggest that novel expression of gastrin (CCK-B) receptors may be generated by gene mutation or amplification during carcinogenesis and may play an important role in promoting tumor growth.

[Glaucomatous hemodynamic changes in central retinal artery and ocular artery]

The hemodynamics of ocular artery (OA) and central retinal artery (CRA) in 100 eyes of 50 normal subjects and 61 eyes of 39 patients with glaucoma were studied with colour doppler image technique. The results showed the hemodynamic characteristics about normal and glaucomatous eyes and that the ischemic change of CRA was one of the high risk factors in glaucomatous visual functional damages. We propose a new classification of glaucomatous hemodynamics and the clinical application of hemodynamic parameters in glaucoma diagnosis. We also, for the first time, make use of hydrodynamic pressure to calculate the retinal perfusion pressure, which explain the phenomena of intraocular pressure increasing with blood flow decreasing and the effect of hyperviscosity as well as cardiovascular disease on glaucoma. A new approach to the research of glaucoma is presented.

[The experimental studies of the effect of Forskolin on the lowering of intraocular pressure]

The effect of the domestic Forskolin on lowering the intraocular pressure (IOP) of rabbits was studied. The results showed that the Forskolin significantly lowered the normal IOP of rabbits and blocked the ocular hypertension induced by water load in rabbits (p < 0.01). The maximum decrease value of 2%, 1% and 0.5% of the Forskolin was 0.59. 0.36 and 0.19 kPa (1 kPa = 7.5 mmHg), which showed the noticeable dose-effect relationship. Topical ocular application of Forskolin lowered IOP in 1/2 hour, reached to a peak in 2-3 hours and remained significantly for 10 hours. The pupillary diameter did not change when IOP were reduced. Furthermore, the Forskolin had potent stimulative properties to adenylate cyclase (AC). The greater the ability of the Forskolin to stimulate AC, the stronger the effect of IOP lowering.

[Computerized image analysis for retinal nerve fiber layer: a preliminary report]

The principle and method for analysing the white-black photographs of retinal nerve fiber layer (RNFL) by using the technique of computerized image analysis were introduced. An objective and quantitative result of RNFL on the white-black photograph was initially obtained, and using the technique of fulse colour, each of the RNFL could be showed, which seem to have more advantages than observing RNFL on a white-black photograph.

Activators of protein kinase C induce p34cdc2 histone H1 kinase stimulation in Swiss 3T3 fibroblasts

Phorbol-12,13-dibutyrate and 1,2-dioctanoylglycerol, activators of protein kinase C (PKC) that stimulate DNA synthesis in serum-deprived Swiss 3T3 fibroblasts, induce histone H1 kinase activity associated with anti-cdc2 immunoprecipitates after a lag period of 15h, a time point close to G1/S boundary of the cell cycle in these cells. Downregulation of PKC does not affect the basal cdc2 kinase activity, but potently inhibits both phorbol dibutyrate- and dioctanoylglycerol-induced cdc2 kinase activation. Phorbol dibutyrate induces a dramatic increase in the p34cdc2 protein level as well as the appearance of p35-p36 forms of cdc2 on Western blot. In PKC-downregulated cells, the p34 form of cdc2 remains elevated but p35-p36 forms do not appear upon phorbol dibutyrate stimulation. These results demonstrate that PKC activation leads to cdc2 kinase activation in mitogenically responsive Swiss 3T3 cells, and strongly suggest that both expression of p34cdc2 protein and its posttranslational modification(s) are involved in this process. Western blot analysis of PKC isozymes suggests that either PKC alpha, PKC delta or PKC epsilon may be involved in p34cdc2 kinase activation and mitogenesis.

Inflammation and platelet-activating factor production during hepatic ischemia/reperfusion

The role of platelet-activating factor as a potential mediator of hepatic inflammatory injury associated with liver ischemia/reperfusion was investigated using a partial no-flow model in rats in vivo. Platelet-activating factor levels of livers from sham-operated rats and from animals experiencing hepatic reperfusion for less than 6 hr were very low. They were observed to increase significantly after 12 hr of reperfusion and reached peak levels after a 24-hr reperfusion period, a time when maximal hepatic injury and inflammation occurred. Treatment of experimental rats with WEB2170, a platelet-activating factor receptor antagonist, attenuated the hepatic injury and inflammation, as evidenced by decreases in plasma ALT and in hepatocyte necrosis and neutrophil infiltration. Both inactivation of Kupffer cells with gadolinium chloride and inhibition of the formation of reactive oxygen species with allopurinol reduced platelet-activating factor production in the liver, whereas induction of neutropenia had no effect, suggesting that interaction of Kupffer cells with oxygen-derived free radicals may be a plausible mechanism for hepatic platelet-activating factor accumulation. It is concluded that platelet-activating factor contributes to the inflammatory consequences of ischemia/reperfusion underlying late-phase hepatic injury.

Local cerebral blood flow responses in rats to hypercapnia and hypoxia in the rostral ventrolateral medulla and in the cortex

The effects of hypercapnia and hypoxia on two local cerebral blood flows in the parietal cortex (PC-BF) and rostral ventrolateral medulla (RVLM-BF) were examined using laser Doppler flowmetry in anesthetized rats. Hypercapnia for 45 s duration at the end-tidal CO2 between 5% and 10%, induced by increasing inspiratory CO2, increased both cerebral blood flows and systemic blood pressure in a degree-dependent manner. The response of RVLM-BF was significantly stronger than that of PC-BF. Both cerebral blood flow responses to hypercapnia were not influenced by cutting peripheral chemoreceptor afferent nerves. Hypoxia for 45 s duration at the end-tidal O2 between 12% and 6%, induced by decreasing inspiratory O2, produced an increase of similar magnitude in both RVLM and PC local blood flows in a degree-dependent manner and a decrease in systemic blood pressure. The responses of both PC-BF and RVLM-BF to hypoxia were significantly diminished after cutting peripheral chemoreceptor afferent nerves. It is concluded that: (1) the RVLM-BF is much more sensitive to hypercapnia than the PC-BF; and (2) activation of peripheral arterial chemoreceptors possibly contributes to hypoxia-induced increase in the RVLM-BF and PC-BF.

Role of platelet-activating factor in hepatic responses after bile duct ligation in rats

Role of platelet-activating factor (PAF) as a potential mediator of hepatic pathophysiology was investigated using a rat model of obstructive jaundice. Over a 1-wk course of bile duct ligation, a sixfold increase in tissue levels of PAF (1.57 +/- 0.43 ng/g vs. control 0.24 +/- 0.08 ng/g) occurred in the liver, whereas no change was observed in PAF levels in plasma. Concomitantly, endotoxin was detected in portal blood drawn from jaundiced rats, and antagonism of the putative effect of endotoxin by neomycin plus polymyxin B reduced local PAF concentrations in livers from jaundiced animals. Induction of neutropenia failed to alter the elevated hepatic PAF concentrations. Moreover, a large quantity of PAF was released spontaneously from Kupffer cells isolated from livers derived from jaundiced rats but not from endothelial cells or hepatocytes from the same animals. An in vitro study using cultured Kupffer cells from normal rats indicated that Kupffer cells secreted a significant amount of PAF in response to lipopolysaccharide challenge; pretreatment of cells with polymyxin B prevented this stimulated PAF release. Treatment of animals with either of two PAF receptor antagonists (BN 52021 and WEB 2170) partially prevented the increase in tissue levels of eicosanoids and O2-derived free radicals and partially alleviated liver injury as judged by the appearance of glutamate-pyruvate transaminase in the plasma of jaundiced rats. The present study indicates 1) that endogenous PAF may be an important signaling mediator for the hepatic inflammatory alterations associated with short-term bile duct ligation and 2) that the interaction of Kupffer cells with portal endotoxin is the mechanism by which PAF is produced locally.

Inhibitory effect of interferon and tumor necrosis factor on human luteal function in vitro

OBJECTIVE

To investigate whether immunological mechanisms may be involved in human luteal function.

DESIGN

The effects of the cytokines, interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) on steroidogenesis by human luteal cells were examined in vitro. The dispersed human luteal cells, obtained from a total of 17 women at laparotomy, were cultured separately in the presence or absence of human chorionic gonadotropin (hCG) and IFNs/TNF-alpha with the medium being replaced at 48 hours. The medium was collected at 48 and 96 hours for steroid assays.

RESULTS

The IFN-alpha had no significant effect on the production of estradiol or progesterone (P), whereas a dose-related inhibition of basal, as well as hCG-stimulated P formation, was observed after the addition of IFN-gamma (10 to 1,000 U/mL). Progesterone production was inhibited to about 45% of the control at 48 hours and even lower at 96 hours (n = 6, P < 0.001). The combination of IFN-gamma and low doses of TNF-alpha induced a further significant inhibition, whereas there was no effect of TNF-alpha alone. This inhibitory effect of IFN-gamma could be completely neutralized with a monoclonal antibody to IFN-gamma. Incubation with the antibody alone increased the production of P from luteal cells in culture, suggesting a local tonic inhibitory action of endogenous IFN-gamma.

CONCLUSION

Interferon-gamma and TNF-alpha, whose function classically is known as antiviral, also may play a role in human luteal regression by inhibiting luteal P production.

Influence of dissolved oxygen concentration on the biosynthesis of cephalosporin C

Cephalosporin C was produced by a highly productive strain of Cephalosporium acremonium under industrial production conditions by fed-batch cultivation in a 40-l stirred-tank reactor using a complex medium containing 50 g l-1 peanut flour. The influence of dissolved oxygen concentration (pO2, DOC), which was maintained at different constant levels between 5 and 40% of its saturation value, during the production phase by means of a parameter-adaptive pO2-controller, on the cephalosporin C biosynthesis, was investigated. The concentrations of cephalosporin C (CPC) and its precursors penicillin N (PEN N), deacetoxycephalosporin C (DAOC), and deacetylcephalosporin C (DAC) were monitored by on-line HPLC. The concentrations of amino acids, valine (VAL), cysteine (CYS), alpha-amino-adipic acid (alpha-AAA), the dipeptide alpha-amino-adipyl-cysteine (AC), and the tripeptide alpha-amino-adipyl-cysteinyl-valine (ACV) were determined by off-line HPLC. By reducing the pO2 in the production phase from 40 to 5% of its saturation value, the CPC concentration diminished from 7.2 to 1.1 g l-1 and the PEN N concentration increased from 2.57 to 7.65 g l-1. The DAC concentration also dropped from 3.13 to 0.42 g l-1; however, the DAOC concentration was less influenced. The concentrations of AC and ACV were also less affected. The small DOC did not lead to an accumulation of the intermediate AC and ACV during the production phase. With increasing DOC in the range of 5-20%, the maximal specific production rate, the cell mass concentration-based and the substrate-based yield coefficients for CPC increased almost linearly, and fell back for PEN N.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet-activating factor as an intercellular signal in neutrophil-dependent platelet activation

The role of platelet-activating factor (PAF) in heterotypic cell to cell interactions in a rabbit neutrophil-platelet mixture model was investigated. Platelets were exposed to each of three chemotactic agonists: PAF, leukotriene B4 (LTB4), or FMLP. Only PAF stimulated aggregation, [3H]serotonin secretion, and cytosolic Ca2+ mobilization in platelets alone. However, platelets were stimulated by LTB4 and FMLP in the presence of neutrophils. This neutrophil-dependent platelet activation was blocked by pretreatment of platelets with PAF receptor antagonists, and was prevented by desensitization of platelets to PAF. Furthermore, the time-course of platelet activation showed a positive correlation with PAF production by neutrophils stimulated with either LTB4 or FMLP. The PAF-mediated neutrophil-platelet interaction was dependent on direct cell to cell contact, as demonstrated by experiments in which the majority of newly formed PAF was neutrophil associated (rather than released). Platelet activation did not occur when the neutrophil-platelet mixture was not stirred, minimizing cell to cell contact, or when platelets were challenged with a cell-free supernatant prepared from neutrophils activated with LTB4 or FMLP. Finally, the neutrophil-platelet interaction was abolished by SC-49992, a peptidomimetic of the fibrinogen binding sequence Arg-Gly-Asp-Phe, indicating a Arg-Gly-Asp-specific recognition mechanism. Our results demonstrate that neutrophil-generated PAF plays a crucial role in neutrophil-dependent platelet activation in this model system. This type of intercellular signaling event may be important in certain inflammatory or thrombotic processes.

Platelet-activating factor as an intercellular signal in neutrophil-dependent platelet activation

The role of platelet-activating factor (PAF) in heterotypic cell to cell interactions in a rabbit neutrophil-platelet mixture model was investigated. Platelets were exposed to each of three chemotactic agonists: PAF, leukotriene B4 (LTB4), or FMLP. Only PAF stimulated aggregation, [3H]serotonin secretion, and cytosolic Ca2+ mobilization in platelets alone. However, platelets were stimulated by LTB4 and FMLP in the presence of neutrophils. This neutrophil-dependent platelet activation was blocked by pretreatment of platelets with PAF receptor antagonists, and was prevented by desensitization of platelets to PAF. Furthermore, the time-course of platelet activation showed a positive correlation with PAF production by neutrophils stimulated with either LTB4 or FMLP. The PAF-mediated neutrophil-platelet interaction was dependent on direct cell to cell contact, as demonstrated by experiments in which the majority of newly formed PAF was neutrophil associated (rather than released). Platelet activation did not occur when the neutrophil-platelet mixture was not stirred, minimizing cell to cell contact, or when platelets were challenged with a cell-free supernatant prepared from neutrophils activated with LTB4 or FMLP. Finally, the neutrophil-platelet interaction was abolished by SC-49992, a peptidomimetic of the fibrinogen binding sequence Arg-Gly-Asp-Phe, indicating a Arg-Gly-Asp-specific recognition mechanism. Our results demonstrate that neutrophil-generated PAF plays a crucial role in neutrophil-dependent platelet activation in this model system. This type of intercellular signaling event may be important in certain inflammatory or thrombotic processes.

Ca2+/calmodulin is involved in growth factor-induced retinoblastoma gene product phosphorylation in human vascular endothelial cells

In human vascular endothelial cells, both growth factor-induced DNA synthesis and retinoblastoma gene product (RB) phosphorylation are absolutely dependent on extracellular Ca2+, and are potently inhibited by an active calmodulin antagonist, W-7, but not an inactive analogue, W-12. A reduction in the extracellular Ca2+ or an addition of W-7 as late as 8 h after growth factor stimulation still inhibits both RB phosphorylation and DNA synthesis to the full extent. However, once RB phosphorylation occurs 12-16 h after addition of the growth factors, it is not reversed by subsequent Ca2+ reduction or W-7. These results suggest the existence of a Ca2+/calmodulin-dependent process relatively late in the mitogenic signalling cascade, at a step proximal to RB phosphorylation reaction itself.

[A variable prism]

A new compact and convenient prism consisting of a planoconvex and a planoconcave cylindrical lens varies continuously in strength between 0 and 90 prism diopters. The relationship between the angle of incidence and the prism dioptric power is discussed.

Cloning and functional expression of a mouse gonadotropin-releasing hormone receptor

GnRH plays a pivotal role in the reproductive system, and GnRH analogs have wide therapeutic applications ranging from the treatment of prostatic cancer to infertility. Determination of the predicted structure of the GnRH receptor (GnRHR) would illuminate the mechanisms of receptor activation and regulation and allow directed design of improved GnRH analogs. We report the cloning of a cDNA representing the mouse GnRHR and confirm its identity using Xenopus oocyte expression. Injection of sense RNA transcript leads to the expression of a functional, high affinity GnRHR. Expression of the GnRHR using gonadotrope cell line RNA, however, is blocked by an antisense oligonucleotide. In situ hybridization in the rat anterior pituitary reveals a characteristic GnRHR distribution. The nucleotide sequence encodes a 327-amino acid protein which has the seven putative transmembrane domains characteristic of G protein-coupled receptors, but which lacks a typical intracellular C-terminus. The unusual structure and novel potential regulatory domain of the GnRHR may explain unique aspects of its signal transduction and regulation.

Influence of medium composition on the cephalosporin C production with a highly productive strain Cephalosporium acremonium

Cephalosporin production by a highly productive Cephalosporium acremonium strain was carried out and optimized by fed-batch operation in a 40 l stirred tank reactor using a complex medium containing 30-120 g l-1 peanut flour. The concentrations of cephalosporin C (CPC) and its precursors: penicillin N (PEN N), deacetoxy cephalosporin C (DAOC), and deacetyl cephalosporin C (DAC) were monitored with an on-line HPLC. The concentrations of amino acids valine (VAL), cysteine (CYS), alpha-amino adipic acid (alpha-AAA), the dipeptide alpha-amino-adipyl-cysteine (AC), and the tripeptide alpha-amino-adipyl-cysteinyl-valine (ACV), were determined off-line by HPLC. The RNA content and dry weight of the sediment as well as the oxygen transfer rate (OTR) and the CO2 production rate (CPR) were used to calculate the cell mass concentration (X). The influences of peanut flour (PF) and the on-line monitored and controlled medium components: glucose (GLU), phosphate, methionine (MET) as well as the dissolved oxygen (DOC) on the cell growth, the product formation, and the pathway of cephalosporin C biosynthesis were investigated and evaluated. When the glucose fed-batch cycle was optimized and oxygen transfer limitation was avoided (DOC greater than 20% of the saturation value), high process performance (103.5 g l-1 X, 11.84 g l-1 CPC, a maximum CPC productivity of 118 mg l-1 h-1, and the whole concentration of the beta-lactam antibiotics CPC, DAC, DAOC, PEN N 17.34 g l-1) was achieved by using 100 g l-1 PF in the medium with the optimum concentration of phosphate (260-270 mg l-1) and a low glucose concentration (less than 0.5 g l-1). The cultivations with different medium concentrations demonstrated that the product formation was directly proportional to the cell mass concentration. On the average, the cell mass-based yield coefficient of CPC: YCPC/X amounted to 0.115 g CPC per g cell mass.

Role of platelet-activating factor in pancreatitis-associated acute lung injury in the rat

Acute necrotizing pancreatitis induced by infusion of bile salt into the pancreatic duct in rats is consistently associated with acute lung injury similar to the adult respiratory distress syndrome. The role of platelet-activating factor (PAF) in this pancreatitis-associated remote organ failure (lung injury) was investigated. Pulmonary tissue levels of PAF were increased gradually and reached a level of 1345 +/- 455 pg/g (6 times the control level) at 12 hours after induction of pancreatitis, whereas pancreatic PAF levels were undetectable and blood PAF remained unchanged. This local pulmonary PAF accumulation occurred at approximately the same time as the progression of lung injury. Pulmonary responses detected (i.e., eicosanoid production, leukocytic infiltration, Evan's blue extravasation, beta-glucuronidase release) were attenuated to varying degrees by treatment of rats in which pancreatitis was initiated with the PAF receptor antagonists (WEB2170 and BN52021). Rat lung lavages were examined after a 12-hour course of pancreatitis and no changes in PAF concentration, surfactant content, and phospholipase A2 (PLA2) activity were noted. Intravenous administration of PLA2 promoted pulmonary PAF production in experimental rats with pancreatitis but not in normal rats. This observation indicates that PLA2, which was determined to be elevated in plasma during pancreatitis, may be responsible for the accumulation of PAF in the lung. In conclusion, pancreatitis-associated lung injury appears to result from an endogenous inflammatory response in which PAF may play an important role.

Somatosensory regulation of regional hippocampal blood flow in anesthetized rats

The effect of noxious or non-noxious mechanical stimulation of various cutaneous areas on cerebral blood flow in hippocampus was examined with laser Doppler flowmetry in urethane-anesthetized artificially-ventilated rats. Noxious mechanical stimulation (pinching) of the skin on the face, forepaw, chest, or hindpaw for 20s increased regional hippocampal blood flow (Hpc-BF) and systemic blood pressure, but non-noxious mechanical stimulation (brushing) had no such effect. After the spinal cord was transected at T1 level a forepaw pinch caused no change in blood pressure but still increased Hpc-BF. This suggests that cutaneous noxious stimulation can induce pressor-independent increases in Hpc-BF. The increase in Hpc-BF induced by a forepaw pinch in T1-transected rats was partially reduced by intravenous administration of mecamylamine (2 mg/kg), a nicotinic cholinergic receptor antagonist. Atropine (0.5 mg/kg), a muscarinic cholinergic antagonist was ineffective. These data indicate that the cholinergic vasodilative system is involved in the somatically-induced increase in Hpc-BF via activation of the nicotinic cholinergic receptors.

Suppression of human nasopharyngeal carcinoma cell growth in nude mice by the wild-type p53 gene

Wild-type and mutant human p53 genes were transfected into the nasopharyngeal carcinoma (NPC) cell line CNE-3. Tumorigenicity in nude mice showed that the tumor resulting from the cells transfected with the wild-type p53 gene grew more slowly and was smaller than that from the cells transfected with mutant p53 gene and that from control CNE-3 cells. In contrast, the tumor from the cells transfected with the mutant p53 gene grew faster than that produced by cells transfected with the wild-type p53 gene and that produced by control CNE-3 cells. The results demonstrate that the wild-type p53 gene could inhibit the NPC cell growth in nude mice and the mutant p53 gene could enhance the NPC cell growth in nude mice. The p53 gene may also play an important role in the pathogenesis of NPC.

Successful replantation of digits and restoration of partial hand function: a case report

A case of a five-finger amputation and avulsion injury with salvage of two digits combined with island flap coverage of the remaining skin defect is reported. The salvaged digits were replanted onto the ulnar and radial borders of the hand stump and rotated to oppose one another. Recovery of partial hand function is reported.

Control of inhibin production by dispersed human luteal cells in vitro

The production of inhibin in vitro by dispersed cells from early to mid (Days 16-19) and late stage (Day 23) human corpus luteum (CL) was examined, and the effects of human chorionic gonadotrophin (hCG), follicle stimulating hormone (FSH), oestradiol and testosterone on inhibin production were determined. Corpora lutea from five subjects in the early to mid luteal stage and three subjects in late luteal stage were dispersed with enzymes and the luteal cells cultured in medium supplemented with 5% calf serum and either FSH (1, 10 or 100 ng mL-1), oestradiol-17 beta (2.5, 5 or 10 micrograms mL-1) or testosterone (0.25, 1 or 5 micrograms mL-1) with or without hCG (1 I.U. mL-1). Cells were cultured for 1 to 3 days without changes of medium, and the concentrations of progesterone, oestradiol and immunoreactive inhibin in the medium were measured by radioimmunoassay. Cells from both types of CL produced inhibin in vitro under basal conditions, but only cells from early to mid CLs responded to hCG with a significant increase in inhibin production. Both progesterone and oestradiol production were stimulated by hCG in both groups of CL. Inhibin concentrations in the cell cultures declined with time in culture, particularly in the late CL group, whereas the concentration of steroids increased. Neither FSH, oestradiol nor testosterone significantly changed inhibin production in either CL group. It was concluded that inhibin production by human luteal cells in vitro is influenced by the age of the CL, and is dependent on LH (hCG) but not on FSH or sex steroids.

Bleomycin A2 and B2 purification by flash chromatography for chemical and biochemical studies

The clinically used formulation of the anticancer antibiotic, Blenoxane, is a mixture of bleomycin congeners. A new approach to separating the major A2 and B2 congeners has been developed utilizing the flash chromatography technique. A 5-6-inch column of fine mesh silica gel with a solvent system of 1% ammonium formate:methanol (2:3) was used. Low air pressure was applied to the column to increase the flow rate such that separation was complete in approximately 20 min. Reverse phase size exclusion gravity chromatography with Sephadex G-15 column bedding was an effective, rapid procedure for removal of the 1% ammonium formate, the lowest percentage practical for separating the bleomycins. This separation approach does not damage the antibiotics, as demonstrated by NMR spectroscopy, thin layer chromatography, and DNA cleaving activity. Although not as useful for detection of trace amounts of the drug in biological systems as some of the known HPLC methods, this method is excellent for separating large quantities of the drug (8-32 mg) in order to obtain congeners pure enough for synthetic, biochemical, and biophysical studies.

[Isolation and purification of alpha fetal protein utilizing Act-Ultrogel AcA 22 affinity chromatography]

In the present communication, we report a method for the isolation and purification of alpha FP from fetal corpse homogenate in a single-step procedure using Act-Ultrogel AcA 22 affinity chromatogrpahy column. This method proves to be better than the conventional method in simplicity, fastness and validity with recovery, purity and immunoreactivity. The immunoreactivity of the purified alpha FP labelled by the method of Hunter and Greenwood (1962) was 50-60% (B/T%). This was similar to alpha FP standard (WHO). The results indicate that the 125I-alpha FP is suitable for alpha FP radioimmunoassay.

[Flow cytometric DNA analysis and its relationship with pathology and prognosis in lung carcinoma]

DNA content of paraffin-embedded tumour material from 110 patients with lung carcinoma was measured by means of flow cytometry. Aneuploidy was found in 78% of the patients. The mean DNA ploid, the percentage of hyperdiploidy and the percentage of multiploidy in small cell carcinoma and large cell carcinoma were higher than those obtained in squamous cell carcinoma and adenocarcinoma. These values were also higher in grade III squamous cell carcinoma and adenocarcinoma as compared with grade I and II squamous cell carcinoma, and adenocarcinoma. They were also higher in lung carcinoma with the primary tumor size greater than or equal to 3 cm than that less than 3 cm. The five-year survival rate and mid mean survival time of patients with hyperdiploidy were significantly lower than those of patients with diploidy and hypodiploidy. Conclusively, DNA content is considered closely related to the degree of malignancy of lung carcinoma and may be adapted as a reliable criterion in estimating the prognosis of lung carcinoma.

Efficacy of the immunoblot assay for cysticercosis in pigs and modulated expression of distinct IgM/IgG activities to Taenia solium antigens in experimental infections

A recently invented immunoblot assay for human cysticercosis was evaluated for efficacy in pigs. The test population consists of 45 pigs with parasitologically confirmed cysticercosis, 47 with heterologous infections, 45 SPF or concrete raised control animals. With this group of 137 animals the test performance was 100% sensitive and 100% specific. The antigen-specific responses of immunoglobulin A (IgA), IgG and IgM in four pigs infected with Taenia solium eggs derived from a human were quantified by immunoblot. Antigen-specific activities were observed as early as 1 week postinfection. The first antigen-specific isotypic response was IgM antibodies directed against a glycoprotein at 97 KD (GP97). This activity generally disappeared between the sixth and ninth week postinfection. Between Weeks 5 and 8, IgG activity rose as IgM activity fell. The IgG activity, however, was directed mostly towards GP50 and GP42 antigens. If the same response occurs in people with cysticercosis, identifying specific isotype activity may help to distinguish new infection from old.

Angiotensin II actions in the rabbit proximal tubule. Angiotensin II mediated signaling mechanisms and electrolyte transport in the rabbit proximal tubule

Angiotensin II (AngII) is a potent regulator of electrolyte transport with biphasic effects on salt and HCO3-resorption in proximal tubule epithelia (PCT). In cultured PCT cells, pM to nM AngII activates a GTP-binding protein to inhibit cAMP formation and thus releases inhibition of apical Na/H exchange. Phospholipase A2 is activated by nM to microM AngII releasing arachidonate which is metabolized by a novel P450 epoxygenase to form 5,6-epoxy-eicosatrienoic acid (5,6-EET). 5,6-EET and nM apical AngII cause dihydropyridine-sensitive Ca2+ influx from the extracellular space, inhibition of apical-to-basolateral Na flux, and decrease in epithelial monolayer short circuit current. 5,6-EET also inhibits Na/K-ATPase by 50%. This P450 epoxygenase is physiologically important in the AngII-signaling system because the P450 inhibitor ketoconazole blocks AngII effects while potentiating exogenous 5,6-EET effects. Finally, these AngII-mediated signaling systems are polarized in the PCT with pM basolateral AngII inhibiting adenylate cyclase and nM apical AngII activating PLA2 and subsequent generation of 5,6-EET.

Guatemalan human onchocerciasis. II. Evidence for IgG3 involvement in acquired immunity to Onchocerca volvulus and identification of possible immune-associated antigens

Ag-specific isotypic differences in immune response to Onchocerca volvulus Ag were assessed for 778 long term residents of endemic Guatemalan areas by quantitative ELISA with 5-min incubation steps and immunoblot. The study population was separated into five groups based on clinical status: N+F+, N+F-, N-F+, N-F-H+, and N-F-H-, where N = O. volvulus adults (nodule), F = microfiladermia, and H = history of O. volvulus infection. A subset of 44 individuals with high exposure to onchocerciasis from the N-F-H- group were critically evaluated and designated as "putatively immune." IgG1 reactivity to O. volvulus Ag was elevated in the majority of infected persons, but not in putatively immune individuals. Specific IgG3 levels, however, were equally elevated in all groups. The majority of N+F- persons also had elevated IgG1 levels, but they were lower than those found in F+ persons. IgG3 reactivities to a group of antigens at 20 kDa (GP20) were seen in many uninfected persons and some N+F- persons. In contrast, most F+ persons, react to this Ag with IgG1 and not IgG3. A mangabey inoculated with the infectious larval stage of O. volvulus (L3), but showed no signs of infection, began to recognize GP20 at 2 wk postinoculation. Early recognition of GP20 was possibly elicited by the larval stage. Purified nodule Ag from N+F+ individuals contained GP20, however, identical nodule Ag prepared from N+F- individuals did not. These data suggest that GP20 Ag may be common to both uterine microfilaria and the infectious larval stages. The fact that GP20 is predominantly recognized by IgG3 in putatively immune persons and some N+F- persons suggests that this increased IgG3 activity may be important in acquired immunity to onchocerciasis.

Guatemalan human onchocerciasis. II. Evidence for IgG3 involvement in acquired immunity to Onchocerca volvulus and identification of possible immune-associated antigens

Ag-specific isotypic differences in immune response to Onchocerca volvulus Ag were assessed for 778 long term residents of endemic Guatemalan areas by quantitative ELISA with 5-min incubation steps and immunoblot. The study population was separated into five groups based on clinical status: N+F+, N+F-, N-F+, N-F-H+, and N-F-H-, where N = O. volvulus adults (nodule), F = microfiladermia, and H = history of O. volvulus infection. A subset of 44 individuals with high exposure to onchocerciasis from the N-F-H- group were critically evaluated and designated as "putatively immune." IgG1 reactivity to O. volvulus Ag was elevated in the majority of infected persons, but not in putatively immune individuals. Specific IgG3 levels, however, were equally elevated in all groups. The majority of N+F- persons also had elevated IgG1 levels, but they were lower than those found in F+ persons. IgG3 reactivities to a group of antigens at 20 kDa (GP20) were seen in many uninfected persons and some N+F- persons. In contrast, most F+ persons, react to this Ag with IgG1 and not IgG3. A mangabey inoculated with the infectious larval stage of O. volvulus (L3), but showed no signs of infection, began to recognize GP20 at 2 wk postinoculation. Early recognition of GP20 was possibly elicited by the larval stage. Purified nodule Ag from N+F+ individuals contained GP20, however, identical nodule Ag prepared from N+F- individuals did not. These data suggest that GP20 Ag may be common to both uterine microfilaria and the infectious larval stages. The fact that GP20 is predominantly recognized by IgG3 in putatively immune persons and some N+F- persons suggests that this increased IgG3 activity may be important in acquired immunity to onchocerciasis.

[The preparation of highly purified insulin and its clinical use. Insulin Cooperative Study Group]

Antigenicity of insulin preparations is obviously related to their purity. The average contents of proinsulin, glucagon and pancreatic polypeptide in highly purified insulin (HP-I) produced by us are 76.0, 2.11 and 0.11 ppm respectively. These results are superior to those for domestic conventional crystalline insulin and single peak insulin (SP-I). The antibodies to insulin, proinsulin and pancreatic polypeptide in serum were examined in 24 diabetic patients treated with HP-I for more than 6 months. The positive rates for the above three antibodies were 37.5%, 0% and 0% respectively. The results showed that the antigenicity of HP-I was much lower than that of domestic conventional crystalline insulin and almost the same as that of MC-I from Nordisk, Denmark.

[Pigmentary glaucoma and capsular glaucoma--a clinical and histopathological report]

In this paper, 7 cases (13 eyes) of pigmentary glaucoma and 9 cases (12 eyes) of capsular glaucoma were reported. Pigmentary dispersion in pigmentary glaucoma, pseudo-exfoliation material deposition in capsular glaucoma were the classical characteristics in the anterior segment of the eye, but pigmentary scatter was another clinical feature of capsular glaucoma. The histopathological studies of the trabeculectomy specimens by the light and transmission electron microscopy demonstrated that pigment granules or/and pseudo-exfoliation materials played an important role in obstructing the outflow tract of aqueous humor. In addition, we also discuss the diagnosis and differential diagnosis of both types of glaucoma.

Guatemalan human onchocerciasis. I. Systematic analysis of patient populations, nodular antigens, and specific isotypic reactions

The population from five Guatemalan plantations in areas endemic for onchocerciasis was surveyed, and 1032 individuals were recruited to participate in our study. From physical examination, past clinical history (5 to 8 yr), laboratory evidence and sample availability, a group of 778 long term residents with confirmed disease status were selected for detailed examination. We were able to identify 268 long term residents of endemic areas who had never been infected, 44 of these are from hyper- and mesoendemic areas. The 44 uninfected individuals from the hyper- and mesoendemic areas, because of their considerable exposure to this disease, were classified as "putatively immune." Intact nodules containing adult worms of Onchocerca volvulus were homogenized in the presence of protease inhibitors and fractionated into particulate and aqueous isotonic soluble antigens. Systematic analysis of these Ag fractions showed considerable amounts of Ig, presumably associated with Ag in the form of immune complexes. Individual specific antibody reactions from all 778 patients to nodule Ag were examined. Reactions to O. volvulus antigens by antibodies from patients with confirmed parasitic infections were almost exclusively restricted to IgG1 and IgG4 isotypes. Antigenic activity appeared to be primarily associated with low molecular mass (14 to 29 kDa) components. Some competitive blocking of antibody activities of other isotypes by IgG1 was observed, most notable was that of IgG3 and IgA. IgG4 and IgM activities were not significantly blocked.

Guatemalan human onchocerciasis. I. Systematic analysis of patient populations, nodular antigens, and specific isotypic reactions

The population from five Guatemalan plantations in areas endemic for onchocerciasis was surveyed, and 1032 individuals were recruited to participate in our study. From physical examination, past clinical history (5 to 8 yr), laboratory evidence and sample availability, a group of 778 long term residents with confirmed disease status were selected for detailed examination. We were able to identify 268 long term residents of endemic areas who had never been infected, 44 of these are from hyper- and mesoendemic areas. The 44 uninfected individuals from the hyper- and mesoendemic areas, because of their considerable exposure to this disease, were classified as "putatively immune." Intact nodules containing adult worms of Onchocerca volvulus were homogenized in the presence of protease inhibitors and fractionated into particulate and aqueous isotonic soluble antigens. Systematic analysis of these Ag fractions showed considerable amounts of Ig, presumably associated with Ag in the form of immune complexes. Individual specific antibody reactions from all 778 patients to nodule Ag were examined. Reactions to O. volvulus antigens by antibodies from patients with confirmed parasitic infections were almost exclusively restricted to IgG1 and IgG4 isotypes. Antigenic activity appeared to be primarily associated with low molecular mass (14 to 29 kDa) components. Some competitive blocking of antibody activities of other isotypes by IgG1 was observed, most notable was that of IgG3 and IgA. IgG4 and IgM activities were not significantly blocked.

[Comparison of Spatholobus suberectus Dum, Euonymus alatus (Thunb.) Sieb. and Eupolyphaga sinensis Walker on regulation of plasma lipid]

The Spatholobus suberectus (SS) of hexue type, the Euonymus alatus (EA) of huoxue type and the Eupolyphaga sinensis (ES) of poxue type were selected and their influence on plasma lipid in the experimental hyperlipidemia quails was observed. The ES could raise plasma HDL-C/TC ratio and increase LCAT activity. The SS could raise plasma HDL2-C/HDL3-C ratio. The effect of EA on plasma HDL-C/TC, HDL2-C/HDL3-C and LCAT levels was between SS and ES. All the three huoxue huayu Chinese drugs could lower plasma HDL3-C level and slow down the progress of atherosclerosis to a certain degree. The above-mentioned results show that certain orders exist between the action range of huoxue huayu drugs and their effect on regulating plasma lipid.

Optimization of binding capacity and specificity of protein G on various solid matrices for immunoglobulins

Streptococcal protein G is a more versatile and efficient alternative to staphylococcal protein A in purifying immunoglobin G (IgG) isotypes from various animal species. Optimizations are most dramatic with goat IgG, which binds protein G 55 times better than protein A. Using GammaBind G (a recombinant form of protein G (Genex Corp.)), we optimized binding capacity and specificity for IgG. Protein G was covalently coupled to three different matrices (CNBr-Sepharose, Tresyl-Sepharose, and Affigel-10) and compared with protein A-CNBr-Sepharose. Equal volumes of human, mouse, and goat serum samples were equilibrated into Hepes/NaOH buffers with various ionic strengths (i.e., concentrations of NaCl) and pH values and allowed to bind to affinity columns of proteins G and A. Bound ligands were eluted with 8.0 M urea, 0.05-M Tris/HCl, pH 8.00. Bound fractions were assayed for protein concentration and analyzed by sodium dodecyl sulfate polyacrylamide electrophoresis. The optimal conditions for binding IgG to protein G are 1.0 M NaCl and pH 8.0 for human, mouse, and goat.