Yama/CPP32 beta, a mammalian homolog of CED-3, is a CrmA-inhibitable protease that cleaves the death substrate poly(ADP-ribose) polymerase

Although the mechanism of mammalian apoptosis has not been elucidated, a protease of the CED-3/ICE family is anticipated to be a component of the death machinery. Several lines of evidence predict that this protease cleaves the death substrate poly(ADP-ribose) polymerase (PARP) to a specific 85 kDa form observed during apoptosis, is inhibitable by the CrmA protein, and is distinct from ICE. We cloned a ced-3/ICE-related gene, designated Yama, that encodes a protein identical to CPP32 beta. Purified Yama was a zymogen that, when activated, cleaved PARP to generate the 85 kDa apoptotic fragment. Cleavage of PARP by Yama was inhibited by CrmA but not by an inactive point mutant of CrmA. Furthermore, CrmA blocked cleavage of PARP in cells undergoing apoptosis. We propose that Yama may represent an effector component of the mammalian cell death pathway and suggest that CrmA blocks apoptosis by inhibiting Yama.

[Effect of tripchlorolide (T4) of Tripterygium wilfordii Hook on the production of endothelin-1 by endothelial cells of human umbilical vein]

Tripchlorolide (T4), a single active ingredient of Tripterygium wilfordii Hook was shown to possess both anti-inflammatory and immunosuppressive actions in experimental animals. The paper reports the effect of T4 on the production of endothelin-1 (ET-1) by endothelial cells of human umbilical vein. The cells were incubated with different doses of T4 (2.5, 5, 10 and 20 ng/ml) for 24 hours. By radioimmunoassay the results showed that T4 at concentration of 5 ng/ml significantly inhibited the production of ET-1 by endothelial cell in a dose dependent trend. The significance of T4 action was discussed.

[Effect of NG-nitro-L-arginine methylester on the secretion of endothelin-1 in vivo and in cultured endothelial cells]

We investigated the effect of nitric oxide, derived from L-arginine on the production of endothelin-1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n = 5), mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR) and plasma endothelin-1 level of the femoral artery during hypoxic ventilation (FIO2 = 0.10) were 3.3 +/- 0.4kPa, 68.7 +/- 10.2kPa.s-1/L and 47.2 +/- 17.4ng/L respectively. NG-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase, increased the peak value of mPAP and PVR during hypoxic ventilation to 4.9 +/- 0.6 kPa and 160.9 +/- 34.6kPa. s/L and its effect lasted for 3 hours. Meanwhile, plasma endothelin-1 level in the femoral artery was increased to 68.2 +/- 20.6, 72.8 +/- 20.9, 75.8 +/- 22.7 ng/L at 60, 120, 180 minutes respectively after the injection of L-NAME (P < 0.05 vs hypoxic control before the injection). In cultured endothelial cells from human umbilical veins, endothelin-1 level of culture medium increased significantly in 10(-11) and 10(-7) mol/L L-NAME group (n = 9, P < 0.05 vs control group). These findings indicate that endogenous nitric oxide is an inhibitory modulator of hypoxic pulmonary vasoconstriction and that nitric oxide inhibits the production of endothelin-1 in vivo and in cultured vascular endothelial cells.

Differential expression of protein kinase C isoforms in human colorectal cancers

Protein kinase C (PKC), a serine/threonine kinase central to signal transduction, is implicated in tumor promotion. At present, 10 PKC isoforms have been cloned but their precise tissue-specific role has yet to be defined. In order to determine if PKC is reduced in colorectal cancers (CRC) and if specific PKC isoforms are altered in different stages of human CRC progression, total RNA was extracted from human primary CRC, liver metastases, paired normal mucosa, and liver as well as CRC cell lines and examined for specific PKC isoform mRNA expression. PKC-alpha, beta II, delta, epsilon, eta(L), theta, and zeta were expressed in all tissues examined, while PKC-beta I was not detected. PKC-alpha, beta II, delta, epsilon, and zeta were decreased in most primary CRC. However, the reduction in PKC-beta II was greatest in advanced primary CRC (P < 0.05). Although PKC-gamma was detected in about 29.6% of primary CRC and liver metastases, it was absent from all corresponding normal tissue. In addition, a second band hybridizing to our PKC-gamma probe was uniquely present only in cancerous tissue and not in brain control, suggestive of alternative splicing. PKC-alpha, delta, epsilon, and zeta were present in all cell lines. PKC-beta I/II were both uniformly absent from all cell lines. Since mRNA expression for most PKC isoforms is decreased in CRC, the previously reported decreases in overall PKC activity in CRC are not solely due to a post-translational enzyme modification.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of acute pulmonary alveolar hypoxia on canine plasma endothelin-1 levels]

The effect of acute pulmonary alveolar hypoxia on plasma endothelin (ET)-1 levels was observed in 10 anesthetized dogs (hypoxic group). Plasma ET-1 like immunoreactivity (-LI) levels increased significantly at the fifth, fifteenth, sixtieth minute after hypoxia (fractional inspiratory O2 concentration 10%), but they had no remarkable change at the thirtieth minute. It was suggested that the first peak of ET-1-LI levels (the fifth minute) might be caused by the release of endothelin-1 which was formed before hypoxia and the second peak could be associated with the secretion of ET-1 after hypoxia. The effect of ligustrazine on plasma ET-1-LI levels during hypoxia was also investigated in other 8 anesthetized dogs. Plasma ET-1-LI levels reduced significantly at the fifth minute after the injection of ligustrazine, compared with the hypoxic group. The result demonstrated that ligustrazine can inhibit the release of ET-1, which could be correlated with the blockade of calcium channel caused by ligustrazine.

[Morphometric study of motor cortex in acute focal epilepsy rat induced by coriaria lactone]

Twenty adult male Wistar rats were divided randomly into two groups (10 rats for LM, 10 rats for EM). The experimental rats were injected with convulsive dosage 3.8 microliters (19 micrograms) of coriaria lactone (CL) in the left cerebral motor cortex of the fore limb to induce acute focal epilepsy. The control rats were injected with normal saline of the same volume and at the same location. Motor cortex was cut coronally 2 hours after seizure and the layer V was studied morphometrically. Under x400 and x7000, take photos of focus, parafocus areas respectively for morphometric study. The number of neurons and neuroglias of layer V was counted in the LM photos. The number of presynaptic terminals of the neuropil was counted in the x7000 EM photos and the area fraction of each constitute in the neuropil was measured. The positive results demonstrated that the number of neurons and neuroglias in the focus and parafocus areas of the experimental animals was significantly lower than that in the control group, the side injected was lower than the other side and it was the lowest in the focus. The number and area fraction of the presynaptic terminals of the experimental rats at the focus neuropil decreased significantly, but the area fraction of neuroglial components increased significantly. The authors suggest that the convulsive dosage of CL may have toxic effect on some neurons and neuroglias and therefore to decrease the number of both types of cells and the number and area fraction of presynaptic terminals in the neuropil.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of potential ligands for nuclear receptors in cellular extracts

In response to external stimuli, steroid receptors are directly influenced to transactivate gene expression. Assuming they exist, identification of ligands for orphan steroid receptors is a key to understanding their physiology. In the orphan subgroup of the steroid receptor superfamily, the putative carboxyl terminal ligand-binding domain (LBD) is well conserved among members of the superfamily, which suggests a role in ligand binding. A consequence of ligand binding is the induction of a significant conformational change within the LBD which is necessary for the transactivation function. This characteristic conformational change can be detected by partial proteolytic digestion and has been localized by mutational analysis and epitopic mapping of the LBD using monoclonal antibodies. Based on this finding, a sensitive in vitro assay was developed for the rapid screening and identification of potential ligands for orphan receptors. We examined the patterns of conformational changes in the androgen receptor, glucocorticoid receptor, and progesterone receptor induced by binding of their cognate agonists and antagonists. We demonstrated that the conformational changes induced by ligands can serve as characteristic and reliable markers to distinguish between the ligand-bound and apoprotein states of a receptor. The sensitivity and feasibility of employing this assay to detect new endogenous ligands using fractionated cellular extracts were also tested. The results strongly suggest that unknown compounds can be defined as potential ligands for orphan receptors using this approach.

[Synthesis of terephthalic acid derivatives and their activity on human promyelocytic leukaemia cells HL-60]

There were 13 derivatives of terephthalic acid were synthesized, in which 9 compounds were not found in literature. The 9 compounds were evaluated for their differentiation-inducing activities on human promyelocytic leukaemia cells HL-60. Compounds N1 and N4 possessed potential activity. Their percentage of differentiating effect was 55% (5 x 10(-6) mol/L), but it was less than that of retinoic acid (79%, 10(-7) mol/L).

[The effect of interleukin-2, interleukin-4 and tumor necrosis factor on LAK cells activity]

We studied the effect of single or combination of interleukin-2 (IL-2), interleukin-4 (IL-4) and tumor necrosis factor (TNF) on lymphokine-activated killer cells (LAK) activity which killed both of target cells HepG2 and 2 2,1,5 cells induced for seven days. It was shown that LAK activity induced by the combination of triplet of IL-2, IL-4 and TNF was higher than that induced by single or two of IL-2, IL-4 and TNF, and that enhanced LAK activity was associated with the quantity of IL-2 receptor expression and lysosomes of LAK precursors.

No association between alleles or genotypes at the dopamine transporter gene and schizophrenia

The dopamine transporter gene (DAT1) is an important candidate gene for schizophrenia. A 40-bp VNTR (variable number of tandem repeats) polymorphism of DAT1 has been typed in 105 schizophrenic patients and 98 normal control subjects from Sichuan (China). Compared with allele frequencies for Caucasians reported in the literature, the Chinese population investigated showed a reduced frequency of the 9-copy allele and an increased frequency of the 10-copy allele. The observed frequency of genotypes was in agreement with the expected values according to Hardy-Weinberg equilibrium. No significant difference was found between patients and control subjects with regard to allele frequency, allele prevalence, and genotype counts. The results of the association study presented here are in agreement with the negative results of linkage analyses in schizophrenia pedigrees from Iceland (Kristbjarnarson et al., submitted) and from Utah (Byerley et al., 1993). Taken together, these studies suggest that variation in the dopamine transporter gene (DAT1) is unlikely to be a factor in the etiology of schizophrenia. The observed differences in allele frequencies between Chinese and Caucasian groups suggest that the human transporter gene might be useful for the construction of evolutionary trees in humans and primates as illustrated by Cavalli-Sforza's work (Mountain et al., 1992).

[Synthesis of p-substituted benzoylaminobenzoic acid (methyl esters) and its differentiation induction in activities of human promyelocytic leukemia cells HL-60]

Sixteen p-substituted benzoylaminobenzoic acids and their methyl esters were synthesized, of which nine were not found in literature. All of the topic compounds were evaluated for their differentiation induction in activities of human promyelotic leukemia cells HL-60. Compounds III1, III2, III4, and III5 possessed potential activities. The differentiation rate, of III4 and III5 was 70% respectively. But it was less than that of retinoic acid (97%).

[Quantitative study on cerebral motor cortex structure of kindling rat induced by coriaria lactone]

Ten male Wistar rats were divided into two groups. The experimental rats were injected with subconvulsive dosage of coriaria lactone (1 mg/kg) intramuscularly every 3.5 days to induce kindling seizures. The controls were injected with normal saline. Cerebral motor cortex of kindling rats was taken at the time between seizures and layer V was compared morphologically with that of the control. The number of neurons and neuroglias was counted from light micrographs. The numerical density and length fraction of boutons on the surface of pyramidal somata were measured from electron micrographs with MIAS 300 type image analyser. The number of synapses in neuropil was counted directly and the areal fraction of various constitute in neuropil was measured stereologically from EM photos. In the experimental rats, the number of neurons remained unchanged and the numerical density and length fraction of boutons on the surface of pyramidal somata showed no change, either. The number of synapses (or presynaptic terminals) decreased significantly in neuropil, but the areal fraction of synaptic terminals had no change and the areal fraction of dendrites and unmyelinated fibers decreased. The areal fraction of myelinated fibers increased significantly. The number of neuroglias and the areal fraction of neuroglial processes increased significantly in the experimental rats. The data suggest that the major morphological changes are manifested as a decline in the pyramidal dendritic components, especially dendritic spines, and the axons with its terminals from superficial neurons in motor cortex layer V of the kindling rats induced by coriaria lactone, besides the neurogliosis which is similar to that occurring in other long-term seizures.

Usefulness of carcinoembryonic antigen monitoring despite normal preoperative values in node-positive colon cancer patients

PURPOSE

The aim of our study was to determine to what extent serial carcinoembryonic antigen (CEA) monitoring is helpful in detecting colorectal cancer recurrence in patients if their preoperative serum CEA is normal. Additional major objectives of this study were to correlate CEA immunohistochemical features of the primary tumor with serum CEA levels at the time of tumor recurrence in node-positive colorectal cancer patients with low preoperative CEA values.

METHODS

One hundred fourteen node-positive colorectal cancer patients with preoperative serum CEA levels of < 5.0 ng/ml undergoing clinically curative operations were studied. Primary tumors were evaluated for tissue CEA using the same monoclonal antibody as used for serum CEA determinations utilizing the avidin-biotin-peroxidase immunohistochemical technique.

RESULTS

The exact preoperative serum CEA value did not correlate with tumor grade, immunohistochemical CEA intensity or pattern. In the 32 patients who developed recurrent cancer, the serum CEA at recurrence was greater than 5 ng/ml in 44 percent. All such patients had CEA present in their primary tumor. There was no correlation with the exact preoperative serum CEA, the intensity of the primary tissue CEA, or the localization of such CEA and subsequent serum elevation at recurrence.

CONCLUSION

Serum CEA is a useful marker in the detection of recurrent colorectal cancer despite normal preoperative values.

No association between schizophrenia and homozygosity at the D3 dopamine receptor gene

The D3 dopamine receptor gene is an important candidate gene for schizophrenia, since (because of its almost exclusive expression in the limbic system) it combines the dopamine receptor hypothesis with the limbic system hypothesis of schizophrenia. A BalI restriction fragment length polymorphism of the D3 dopamine receptor gene has been typed in 107 schizophrenic patients and 98 normal controls from Sichuan (China). With regard to alleles or genotypes, no significant differences were obtained between controls from Europe and China, between patients and controls, and between patient subgroups and controls. These results indicate a lack of association between schizophrenia and the D3 dopamine receptor gene in our sample. Our findings are at variance with reports of a significant excess of homozygosity at the D3 dopamine receptor gene in schizophrenic patients from Wales (United Kingdom) and Alsace (France). In conclusion, further studies will be needed with larger samples of patients from Wales and Alsace as well as with samples of different racial groups to prove or disprove the initial positive association between schizophrenia and genotypes of the D3 dopamine receptor gene.

Chemically bonded stationary phases that use synthetic hosts containing aromatic binding clefts: HPLC analysis of nitro-substituted polycyclic aromatic hydrocarbons

The synthesis of hosts with improved binding affinities for nitroaromatic guests is described. Association constants for several host-guest complexes were measured in chloroform solution and ranged over three orders of magnitude. Two hosts were covalently linked to silica gel to produce chemically bonded stationary phases for HPLC. The use of these phases for HPLC analysis of nitro-substituted polycyclic aromatic hydrocarbons is discussed.

Localization of two binding domains for thrombospondin within fibronectin

Thrombospondin is a major glycoprotein of the platelet alpha-granule and is secreted during platelet activation. Several protease-resistant domains of thrombospondin mediate its interactions with components of the extracellular matrix including fibronectin, collagen, heparin, laminin, and fibrinogen. Thrombospondin, as well as fibronectin, is composed of several discretely located biologically active domains. We have characterized the thrombospondin binding domains of plasma fibronectin and determined the binding affinities of the purified domains; fibronectin has at least two binding sites for thrombospondin. Thrombospondin bound specifically to the 29-kDa amino-terminal heparin binding domain of fibronectin as well as to the 31-kDa non-heparin binding domain located within the larger 40-kDa carboxy-terminal fibronectin domain generated by chymotrypsin proteolysis. Platelet thrombospondin interacted with plasma fibronectin in a specific and saturable manner in blot binding as well as solid-phase binding assays. These interactions were independent of divalent cations. Thrombospondin bound to the 29-kDa fibronectin heparin binding domain with a Kd of 1.35 x 10(-9) M. The Kd for the 31-kDa domain of fibronectin was 2.28 x 10(-8) M. The 40-kDa carboxy-terminal fragment bound with a Kd of 1.65 x 10(-8) M. Heparin, which binds to both proteins, inhibited thrombospondin binding to the amino-terminal domain of fibronectin by more than 70%. The heparin effect was less pronounced with the non-heparin binding carboxy-terminal domain of fibronectin. By contrast, the binding affinity of the thrombospondin 150-kDa domain, which itself lacked heparin binding, was not affected by the presence of heparin. Based on these data, we conclude that thrombospondin binds with different affinities to two distinct domains in the fibronectin molecule.

Serosal cytologic study to determine free mesothelial penetration of intraperitoneal colon cancer

BACKGROUND

The presence of complete transmural penetration with tumor cells at the free mesothelial surface in patients with intraperitoneal colon cancer is an important prognostic feature and may alter the decision regarding adjuvant chemotherapy.

METHODS

In this prospective study of 65 patients, specimens obtained by scraping the serosa overlying the primary tumor mass were analyzed by routine Papanicolaou cytologic study.

RESULTS

Malignant cells were present in 23.1% of patients. In 46 patients with histologic pT3 tumors (through the muscularis propria but not through serosa), serosal cytologic study results were positive in 26.1% of patients. Serosal cytologic results were positive from an area of normal colon at least 10 cm proximal or distal to the primary tumor in one patient.

CONCLUSIONS

Serosal cytologic study appeared to be a simple and reliable method to detect serosal penetration and the presence of tumor cells at the mesothelial surface.

[The use of 6-flavor Rehmannia decoction with additives in the prevention of ototoxic deafness induced by gentamicin in guinea pigs]

The purpose of this study is to discuss the effects of the Chinese medicine six-flavor Rehmannia Decoction with additives on preventing deafness induced by gentamicin (GM) in guinea pig by means of testing the thresholds of Preyer's reflex (PR) cochlear microphonic potential (CM), action potential of the auditory nerve (N1) and scanning electron microscope of inner ear (SEM). The results showed that the medicine is effective in reducing the ototoxic effect of GM on inner ear.

Evidence for the existence of O-linked sugar chains consisting of glucose and xylose in bovine thrombospondin

We have recently discovered unusual sugar chains [xylose-glucose and (xylose)2-glucose] linked to a serine residue in the first epidermal growth factor (EGF)-like domains of human and bovine coagulation factors VII, IX, and protein Z. The sequence surrounding this serine residue has a common -Cys-X-Ser-X-Pro-Cys- structure. Since one (residues 533-538) of the three EGF-like domains found in human thrombospondin contains the conserved sequence, we examined the presence of such O-linked sugar chains in bovine thrombospondin (bTSP) and its 210-kDa fragment. Component sugar analysis after pyridylamination (PA) of the acid hydrolysates of the S-aminoethylated proteins revealed that the proteins contain glucose (Glc) and xylose (Xyl). The oligosaccharide moieties released from intact bTSP by hydrazinolysis followed by pyridylamination were separated into two PA-oligosaccharides by high performance liquid chromatography (HPLC). Component sugar analysis of these PA-oligosaccharides indicated that they consist of Glc and Xyl in molar ratios of 1:1 and 1:2 (or 1:3). The reducing ends of both PA-sugar chains were found to be PA-Glc, as judged from the retention time of the HPLC peak of their hydrolysates. The presence of these PA-sugar chains in bTSP was confirmed by HPLC mapping with two different columns, using standard PA-di- or PA-trisaccharide derived from coagulation factors. From these results, we concluded that bTSP contains O-linked sugar chains consisting of Glc and Xyl in one of its three EGF-like domains.

Effect of pentisomide (CM 7857) on myocardial excitation, conduction, repolarization, and refractoriness. An electrophysiological study in humans

The electrophysiological effects of pentisomide upon the intact human heart were evaluated using programmed stimulation and recording of intracardiac monophasic action potentials (MAP) in 17 patients with various ventricular arrhythmias. After i.v. administration of pentisomide, 85-135 mg, the atrial-His interval increased by 8 +/- 12 ms (p less than 0.05) during sinus rhythm and by 13 +/- 21 ms (p less than 0.05) at atrial pacing of 600 ms cycle length (600 ms pacing). The His-ventricular interval also increased by 6 +/- 10 ms during sinus rhythm (p less than 0.05) and by 5 +/- 9 ms at 600 ms pacing (NS). The QRS duration prolonged by 9 +/- 10 ms (p less than 0.01) and 6 +/- 8 ms (p less than 0.01) during 600 and 500 ms ventricular pacing, respectively. The right ventricular MAP duration to 90% repolarization was significantly shortened, by 20 +/- 21 ms (p less than 0.01) during sinus rhythm, by 16 +/- 17 ms (p less than 0.01) at 600 ms ventricular pacing, and by 11 +/- 16 ms (p less than 0.01) at 500 ms ventricular pacing. The corrected QT interval was shortened by 21 +/- 28 ms (p less than 0.01). The present study supports that pentisomide is a class-I antiarrhythmic agent with a marked effect on depolarization (action of class Ia and Ic) and on repolarization (action of class Ib). This unique combination of cellular electrophysiological properties indicates that the clinical antiarrhythmic efficacy of pentisomide may differ from that of hitherto available antiarrhythmic drugs.

Measurement of the refractive index and thermal refractive index coefficients of Nd:YAP crystal

The principal refractive indices of yttrium aluminate crystal doping with 1-wt.% neodymium (Nd:YAP) have been measured by a minimum deviation method for the wavelengths 0.5398, 0.6328, and 1.0795 microm in the temperature range of 289-435 K. The thermal refractive index coefficients have been obtained at these wavelengths, and they are all positive and slightly decrease with increased wavelength. The constants of the single term Sellmeier equation are also given for the 273-420 K temperature range. These constants are in linear relationship with temperature in the 4 x 10(-3) error range.

The genetic polymorphism of complement component C81 (alpha-gamma) in two Chinese populations

The genetic polymorphism of the complement component C81 (alpha-gamma) in two Chinese populations (Beijing and Guangzhou) were investigated, using isoelectric focusing followed by an immunoblotting technique. Three common and two rare phenotypes were observed. The homozygote phenotype C81 A1 ascribed to a rare allele C81*A1 was newly detected. The frequencies calculated for the two common alleles were as follows: C81*A = 0.5674, C81*B = 0.4255 for the Beijing population; C81*A = 0.5117, C81*B = 0.4785 for the Guangzhou population. The gene frequencies of the two common alleles of C81 in both Chinese populations were similar to those for the other ethnic groups thus far reported, and there is no statistically significant difference between the Beijing and the Guangzhou populations.